Search Results: "eof"

1 November 2022

Jonathan Dowland: Halloween playlist 2022

I hope you had a nice Halloween! I've collected together some songs that I've enjoyed over the last couple of years that loosely fit a theme: ambient, instrumental, experimental, industrial, dark, disconcerting, etc. I've prepared a Spotify playlist of most of them, but not all. The list is inline below as well, with many (but not all) tracks linking to Bandcamp, if I could find them there. This is a bit late, sorry. If anyone listens to something here and has any feedback I'd love to hear it. (If you are reading this on an aggregation site, it's possible the embeds won't work. If so, click through to my main site) Spotify playlist: https://open.spotify.com/playlist/3bEvEguRnf9U1RFrNbv5fk?si=9084cbf78c364ac8; The list, with Bandcamp embeds where possible: Some sources
  1. Via Stuart Maconie's Freak Zone
  2. Via Mary Anne Hobbs
  3. Via Lose yourself with
  4. Soma FM - Doomed (Halloween Special)

Paul Wise: FLOSS Activities October 2022

Focus This month I didn't have any particular focus. I just worked on issues in my info bubble.

Changes

Issues

Review

Administration
  • Debian BTS: unarchive/reopen/triage bugs for reintroduced packages nautilus-image-converter, swift-im, runit-services
  • Debian IRC: removed 2 spammers from OFTC, disable anti-spam channel modes for some channels
  • Debian servers: restart processes due to OOM
  • Debian wiki: approve accounts

Communication
  • Initiate discussion about the apt hook protocol
  • Respond to queries from Debian users and contributors on the mailing lists and IRC

Sponsors All work was done on a volunteer basis.

3 October 2022

Paul Wise: FLOSS Activities September 2022

Focus This month I didn't have any particular focus. I just worked on issues in my info bubble.

Changes

Issues

Review

Administration
  • Debian QA services: deploy changes
  • Debian wiki: approve accounts

Communication
  • Respond to queries from Debian users and contributors on the mailing lists and IRC

Sponsors All work was done on a volunteer basis.

27 September 2022

Steve McIntyre: Firmware again - updates, how I'm voting and why!

Updates Back in April I wrote about issues with how we handle firmware in Debian, and I also spoke about it at DebConf in July. Since then, we've started the General Resolution process - this led to a lot of discussion on the the debian-vote mailing list and we're now into the second week of the voting phase. The discussion has caught the interest of a few news sites along the way: My vote I've also had several people ask me how I'm voting myself, as I started this GR in the first place. I'm happy to oblige! Here's my vote, sorted into preference order:
  [1] Choice 5: Change SC for non-free firmware in installer, one installer
  [2] Choice 1: Only one installer, including non-free firmware
  [3] Choice 6: Change SC for non-free firmware in installer, keep both installers
  [4] Choice 2: Recommend installer containing non-free firmware
  [5] Choice 3: Allow presenting non-free installers alongside the free one
  [6] Choice 7: None Of The Above
  [7] Choice 4: Installer with non-free software is not part of Debian
Why have I voted this way? Fundamentally, my motivation for starting this vote was to ask the project for clear positive direction on a sensible way forward with non-free firmware support. Thus, I've voted all of the options that do that above NOTA. On those terms, I don't like Choice 4 here - IMHO it leaves us in the same unclear situation as before. I'd be happy for us to update the Social Contract for clarity, and I know some people would be much more comfortable if we do that explicitly here. Choice 1 was my initial personal preference as we started the GR, but since then I've been convinced that also updating the SC would be a good idea, hence Choice 5. I'd also rather have a single image / set of images produced, for the two reasons I've outlined before. It's less work for our images team to build and test all the options. But, much more importantly: I believe it's less likely to confuse new users. I appreciate that not everybody agrees with me here, and this is part of the reason why we're voting! Other Debian people have also blogged about their voting choices (Gunnar Wolf and Ian Jackson so far), and I thank them for sharing their reasoning too. For the avoidance of doubt: my goal for this vote was simply to get a clear direction on how to proceed here. Although I proposed Choice 1 (Only one installer, including non-free firmware), I also seconded several of the other ballot options. Of course I will accept the will of the project when the result is announced - I'm not going to do anything silly like throw a tantrum or quit the project over this! Finally If you're a DD and you haven't voted already, please do so - this is an important choice for the Debian project.

25 September 2022

Sergio Talens-Oliag: Kubernetes Static Content Server

This post describes how I ve put together a simple static content server for kubernetes clusters using a Pod with a persistent volume and multiple containers: an sftp server to manage contents, a web server to publish them with optional access control and another one to run scripts which need access to the volume filesystem. The sftp server runs using MySecureShell, the web server is nginx and the script runner uses the webhook tool to publish endpoints to call them (the calls will come from other Pods that run backend servers or are executed from Jobs or CronJobs).

HistoryThe system was developed because we had a NodeJS API with endpoints to upload files and store them on S3 compatible services that were later accessed via HTTPS, but the requirements changed and we needed to be able to publish folders instead of individual files using their original names and apply access restrictions using our API. Thinking about our requirements the use of a regular filesystem to keep the files and folders was a good option, as uploading and serving files is simple. For the upload I decided to use the sftp protocol, mainly because I already had an sftp container image based on mysecureshell prepared; once we settled on that we added sftp support to the API server and configured it to upload the files to our server instead of using S3 buckets. To publish the files we added a nginx container configured to work as a reverse proxy that uses the ngx_http_auth_request_module to validate access to the files (the sub request is configurable, in our deployment we have configured it to call our API to check if the user can access a given URL). Finally we added a third container when we needed to execute some tasks directly on the filesystem (using kubectl exec with the existing containers did not seem a good idea, as that is not supported by CronJobs objects, for example). The solution we found avoiding the NIH Syndrome (i.e. write our own tool) was to use the webhook tool to provide the endpoints to call the scripts; for now we have three:
  • one to get the disc usage of a PATH,
  • one to hardlink all the files that are identical on the filesystem,
  • one to copy files and folders from S3 buckets to our filesystem.

Container definitions

mysecureshellThe mysecureshell container can be used to provide an sftp service with multiple users (although the files are owned by the same UID and GID) using standalone containers (launched with docker or podman) or in an orchestration system like kubernetes, as we are going to do here. The image is generated using the following Dockerfile:
ARG ALPINE_VERSION=3.16.2
FROM alpine:$ALPINE_VERSION as builder
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
RUN apk update &&\
 apk add --no-cache alpine-sdk git musl-dev &&\
 git clone https://github.com/sto/mysecureshell.git &&\
 cd mysecureshell &&\
 ./configure --prefix=/usr --sysconfdir=/etc --mandir=/usr/share/man\
 --localstatedir=/var --with-shutfile=/var/lib/misc/sftp.shut --with-debug=2 &&\
 make all && make install &&\
 rm -rf /var/cache/apk/*
FROM alpine:$ALPINE_VERSION
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
COPY --from=builder /usr/bin/mysecureshell /usr/bin/mysecureshell
COPY --from=builder /usr/bin/sftp-* /usr/bin/
RUN apk update &&\
 apk add --no-cache openssh shadow pwgen &&\
 sed -i -e "s ^.*\(AuthorizedKeysFile\).*$ \1 /etc/ssh/auth_keys/%u "\
 /etc/ssh/sshd_config &&\
 mkdir /etc/ssh/auth_keys &&\
 cat /dev/null > /etc/motd &&\
 add-shell '/usr/bin/mysecureshell' &&\
 rm -rf /var/cache/apk/*
COPY bin/* /usr/local/bin/
COPY etc/sftp_config /etc/ssh/
COPY entrypoint.sh /
EXPOSE 22
VOLUME /sftp
ENTRYPOINT ["/entrypoint.sh"]
CMD ["server"]
The /etc/sftp_config file is used to configure the mysecureshell server to have all the user homes under /sftp/data, only allow them to see the files under their home directories as if it were at the root of the server and close idle connections after 5m of inactivity:
etc/sftp_config
# Default mysecureshell configuration
<Default>
   # All users will have access their home directory under /sftp/data
   Home /sftp/data/$USER
   # Log to a file inside /sftp/logs/ (only works when the directory exists)
   LogFile /sftp/logs/mysecureshell.log
   # Force users to stay in their home directory
   StayAtHome true
   # Hide Home PATH, it will be shown as /
   VirtualChroot true
   # Hide real file/directory owner (just change displayed permissions)
   DirFakeUser true
   # Hide real file/directory group (just change displayed permissions)
   DirFakeGroup true
   # We do not want users to keep forever their idle connection
   IdleTimeOut 5m
</Default>
# vim: ts=2:sw=2:et
The entrypoint.sh script is the one responsible to prepare the container for the users included on the /secrets/user_pass.txt file (creates the users with their HOME directories under /sftp/data and a /bin/false shell and creates the key files from /secrets/user_keys.txt if available). The script expects a couple of environment variables:
  • SFTP_UID: UID used to run the daemon and for all the files, it has to be different than 0 (all the files managed by this daemon are going to be owned by the same user and group, even if the remote users are different).
  • SFTP_GID: GID used to run the daemon and for all the files, it has to be different than 0.
And can use the SSH_PORT and SSH_PARAMS values if present. It also requires the following files (they can be mounted as secrets in kubernetes):
  • /secrets/host_keys.txt: Text file containing the ssh server keys in mime format; the file is processed using the reformime utility (the one included on busybox) and can be generated using the gen-host-keys script included on the container (it uses ssh-keygen and makemime).
  • /secrets/user_pass.txt: Text file containing lines of the form username:password_in_clear_text (only the users included on this file are available on the sftp server, in fact in our deployment we use only the scs user for everything).
And optionally can use another one:
  • /secrets/user_keys.txt: Text file that contains lines of the form username:public_ssh_ed25519_or_rsa_key; the public keys are installed on the server and can be used to log into the sftp server if the username exists on the user_pass.txt file.
The contents of the entrypoint.sh script are:
entrypoint.sh
#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
# Expects SSH_UID & SSH_GID on the environment and uses the value of the
# SSH_PORT & SSH_PARAMS variables if present
# SSH_PARAMS
SSH_PARAMS="-D -e -p $ SSH_PORT:=22  $ SSH_PARAMS "
# Fixed values
# DIRECTORIES
HOME_DIR="/sftp/data"
CONF_FILES_DIR="/secrets"
AUTH_KEYS_PATH="/etc/ssh/auth_keys"
# FILES
HOST_KEYS="$CONF_FILES_DIR/host_keys.txt"
USER_KEYS="$CONF_FILES_DIR/user_keys.txt"
USER_PASS="$CONF_FILES_DIR/user_pass.txt"
USER_SHELL_CMD="/usr/bin/mysecureshell"
# TYPES
HOST_KEY_TYPES="dsa ecdsa ed25519 rsa"
# ---------
# FUNCTIONS
# ---------
# Validate HOST_KEYS, USER_PASS, SFTP_UID and SFTP_GID
_check_environment()  
  # Check the ssh server keys ... we don't boot if we don't have them
  if [ ! -f "$HOST_KEYS" ]; then
    cat <<EOF
We need the host keys on the '$HOST_KEYS' file to proceed.
Call the 'gen-host-keys' script to create and export them on a mime file.
EOF
    exit 1
  fi
  # Check that we have users ... if we don't we can't continue
  if [ ! -f "$USER_PASS" ]; then
    cat <<EOF
We need at least the '$USER_PASS' file to provision users.
Call the 'gen-users-tar' script to create a tar file to create an archive that
contains public and private keys for users, a 'user_keys.txt' with the public
keys of the users and a 'user_pass.txt' file with random passwords for them 
(pass the list of usernames to it).
EOF
    exit 1
  fi
  # Check SFTP_UID
  if [ -z "$SFTP_UID" ]; then
    echo "The 'SFTP_UID' can't be empty, pass a 'GID'."
    exit 1
  fi
  if [ "$SFTP_UID" -eq "0" ]; then
    echo "The 'SFTP_UID' can't be 0, use a different 'UID'"
    exit 1
  fi
  # Check SFTP_GID
  if [ -z "$SFTP_GID" ]; then
    echo "The 'SFTP_GID' can't be empty, pass a 'GID'."
    exit 1
  fi
  if [ "$SFTP_GID" -eq "0" ]; then
    echo "The 'SFTP_GID' can't be 0, use a different 'GID'"
    exit 1
  fi
 
# Adjust ssh host keys
_setup_host_keys()  
  opwd="$(pwd)"
  tmpdir="$(mktemp -d)"
  cd "$tmpdir"
  ret="0"
  reformime <"$HOST_KEYS"   ret="1"
  for kt in $HOST_KEY_TYPES; do
    key="ssh_host_$ kt _key"
    pub="ssh_host_$ kt _key.pub"
    if [ ! -f "$key" ]; then
      echo "Missing '$key' file"
      ret="1"
    fi
    if [ ! -f "$pub" ]; then
      echo "Missing '$pub' file"
      ret="1"
    fi
    if [ "$ret" -ne "0" ]; then
      continue
    fi
    cat "$key" >"/etc/ssh/$key"
    chmod 0600 "/etc/ssh/$key"
    chown root:root "/etc/ssh/$key"
    cat "$pub" >"/etc/ssh/$pub"
    chmod 0600 "/etc/ssh/$pub"
    chown root:root "/etc/ssh/$pub"
  done
  cd "$opwd"
  rm -rf "$tmpdir"
  return "$ret"
 
# Create users
_setup_user_pass()  
  opwd="$(pwd)"
  tmpdir="$(mktemp -d)"
  cd "$tmpdir"
  ret="0"
  [ -d "$HOME_DIR" ]   mkdir "$HOME_DIR"
  # Make sure the data dir can be managed by the sftp user
  chown "$SFTP_UID:$SFTP_GID" "$HOME_DIR"
  # Allow the user (and root) to create directories inside the $HOME_DIR, if
  # we don't allow it the directory creation fails on EFS (AWS)
  chmod 0755 "$HOME_DIR"
  # Create users
  echo "sftp:sftp:$SFTP_UID:$SFTP_GID:::/bin/false" >"newusers.txt"
  sed -n "/^[^#]/   s/:/ /p  " "$USER_PASS"   while read -r _u _p; do
    echo "$_u:$_p:$SFTP_UID:$SFTP_GID::$HOME_DIR/$_u:$USER_SHELL_CMD"
  done >>"newusers.txt"
  newusers --badnames newusers.txt
  # Disable write permission on the directory to forbid remote sftp users to
  # remove their own root dir (they have already done it); we adjust that
  # here to avoid issues with EFS (see before)
  chmod 0555 "$HOME_DIR"
  # Clean up the tmpdir
  cd "$opwd"
  rm -rf "$tmpdir"
  return "$ret"
 
# Adjust user keys
_setup_user_keys()  
  if [ -f "$USER_KEYS" ]; then
    sed -n "/^[^#]/   s/:/ /p  " "$USER_KEYS"   while read -r _u _k; do
      echo "$_k" >>"$AUTH_KEYS_PATH/$_u"
    done
  fi
 
# Main function
exec_sshd()  
  _check_environment
  _setup_host_keys
  _setup_user_pass
  _setup_user_keys
  echo "Running: /usr/sbin/sshd $SSH_PARAMS"
  # shellcheck disable=SC2086
  exec /usr/sbin/sshd -D $SSH_PARAMS
 
# ----
# MAIN
# ----
case "$1" in
"server") exec_sshd ;;
*) exec "$@" ;;
esac
# vim: ts=2:sw=2:et
The container also includes a couple of auxiliary scripts, the first one can be used to generate the host_keys.txt file as follows:
$ docker run --rm stodh/mysecureshell gen-host-keys > host_keys.txt
Where the script is as simple as:
bin/gen-host-keys
#!/bin/sh
set -e
# Generate new host keys
ssh-keygen -A >/dev/null
# Replace hostname
sed -i -e 's/@.*$/@mysecureshell/' /etc/ssh/ssh_host_*_key.pub
# Print in mime format (stdout)
makemime /etc/ssh/ssh_host_*
# vim: ts=2:sw=2:et
And there is another script to generate a .tar file that contains auth data for the list of usernames passed to it (the file contains a user_pass.txt file with random passwords for the users, public and private ssh keys for them and the user_keys.txt file that matches the generated keys). To generate a tar file for the user scs we can execute the following:
$ docker run --rm stodh/mysecureshell gen-users-tar scs > /tmp/scs-users.tar
To see the contents and the text inside the user_pass.txt file we can do:
$ tar tvf /tmp/scs-users.tar
-rw-r--r-- root/root        21 2022-09-11 15:55 user_pass.txt
-rw-r--r-- root/root       822 2022-09-11 15:55 user_keys.txt
-rw------- root/root       387 2022-09-11 15:55 id_ed25519-scs
-rw-r--r-- root/root        85 2022-09-11 15:55 id_ed25519-scs.pub
-rw------- root/root      3357 2022-09-11 15:55 id_rsa-scs
-rw------- root/root      3243 2022-09-11 15:55 id_rsa-scs.pem
-rw-r--r-- root/root       729 2022-09-11 15:55 id_rsa-scs.pub
$ tar xfO /tmp/scs-users.tar user_pass.txt
scs:20JertRSX2Eaar4x
The source of the script is:
bin/gen-users-tar
#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
USER_KEYS_FILE="user_keys.txt"
USER_PASS_FILE="user_pass.txt"
# ---------
# MAIN CODE
# ---------
# Generate user passwords and keys, return 1 if no username is received
if [ "$#" -eq "0" ]; then
  return 1
fi
opwd="$(pwd)"
tmpdir="$(mktemp -d)"
cd "$tmpdir"
for u in "$@"; do
  ssh-keygen -q -a 100 -t ed25519 -f "id_ed25519-$u" -C "$u" -N ""
  ssh-keygen -q -a 100 -b 4096 -t rsa -f "id_rsa-$u" -C "$u" -N ""
  # Legacy RSA private key format
  cp -a "id_rsa-$u" "id_rsa-$u.pem"
  ssh-keygen -q -p -m pem -f "id_rsa-$u.pem" -N "" -P "" >/dev/null
  chmod 0600 "id_rsa-$u.pem"
  echo "$u:$(pwgen -s 16 1)" >>"$USER_PASS_FILE"
  echo "$u:$(cat "id_ed25519-$u.pub")" >>"$USER_KEYS_FILE"
  echo "$u:$(cat "id_rsa-$u.pub")" >>"$USER_KEYS_FILE"
done
tar cf - "$USER_PASS_FILE" "$USER_KEYS_FILE" id_* 2>/dev/null
cd "$opwd"
rm -rf "$tmpdir"
# vim: ts=2:sw=2:et

nginx-scsThe nginx-scs container is generated using the following Dockerfile:
ARG NGINX_VERSION=1.23.1
FROM nginx:$NGINX_VERSION
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
RUN rm -f /docker-entrypoint.d/*
COPY docker-entrypoint.d/* /docker-entrypoint.d/
Basically we are removing the existing docker-entrypoint.d scripts from the standard image and adding a new one that configures the web server as we want using a couple of environment variables:
  • AUTH_REQUEST_URI: URL to use for the auth_request, if the variable is not found on the environment auth_request is not used.
  • HTML_ROOT: Base directory of the web server, if not passed the default /usr/share/nginx/html is used.
Note that if we don t pass the variables everything works as if we were using the original nginx image. The contents of the configuration script are:
docker-entrypoint.d/10-update-default-conf.sh
#!/bin/sh
# Replace the default.conf nginx file by our own version.
set -e
if [ -z "$HTML_ROOT" ]; then
  HTML_ROOT="/usr/share/nginx/html"
fi
if [ "$AUTH_REQUEST_URI" ]; then
  cat >/etc/nginx/conf.d/default.conf <<EOF
server  
  listen       80;
  server_name  localhost;
  location /  
    auth_request /.auth;
    root  $HTML_ROOT;
    index index.html index.htm;
   
  location /.auth  
    internal;
    proxy_pass $AUTH_REQUEST_URI;
    proxy_pass_request_body off;
    proxy_set_header Content-Length "";
    proxy_set_header X-Original-URI \$request_uri;
   
  error_page   500 502 503 504  /50x.html;
  location = /50x.html  
    root /usr/share/nginx/html;
   
 
EOF
else
  cat >/etc/nginx/conf.d/default.conf <<EOF
server  
  listen       80;
  server_name  localhost;
  location /  
    root  $HTML_ROOT;
    index index.html index.htm;
   
  error_page   500 502 503 504  /50x.html;
  location = /50x.html  
    root /usr/share/nginx/html;
   
 
EOF
fi
# vim: ts=2:sw=2:et
As we will see later the idea is to use the /sftp/data or /sftp/data/scs folder as the root of the web published by this container and create an Ingress object to provide access to it outside of our kubernetes cluster.

webhook-scsThe webhook-scs container is generated using the following Dockerfile:
ARG ALPINE_VERSION=3.16.2
ARG GOLANG_VERSION=alpine3.16
FROM golang:$GOLANG_VERSION AS builder
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
ENV WEBHOOK_VERSION 2.8.0
ENV WEBHOOK_PR 549
ENV S3FS_VERSION v1.91
WORKDIR /go/src/github.com/adnanh/webhook
RUN apk update &&\
 apk add --no-cache -t build-deps curl libc-dev gcc libgcc patch
RUN curl -L --silent -o webhook.tar.gz\
 https://github.com/adnanh/webhook/archive/$ WEBHOOK_VERSION .tar.gz &&\
 tar xzf webhook.tar.gz --strip 1 &&\
 curl -L --silent -o $ WEBHOOK_PR .patch\
 https://patch-diff.githubusercontent.com/raw/adnanh/webhook/pull/$ WEBHOOK_PR .patch &&\
 patch -p1 < $ WEBHOOK_PR .patch &&\
 go get -d && \
 go build -o /usr/local/bin/webhook
WORKDIR /src/s3fs-fuse
RUN apk update &&\
 apk add ca-certificates build-base alpine-sdk libcurl automake autoconf\
 libxml2-dev libressl-dev mailcap fuse-dev curl-dev
RUN curl -L --silent -o s3fs.tar.gz\
 https://github.com/s3fs-fuse/s3fs-fuse/archive/refs/tags/$S3FS_VERSION.tar.gz &&\
 tar xzf s3fs.tar.gz --strip 1 &&\
 ./autogen.sh &&\
 ./configure --prefix=/usr/local &&\
 make -j && \
 make install
FROM alpine:$ALPINE_VERSION
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
WORKDIR /webhook
RUN apk update &&\
 apk add --no-cache ca-certificates mailcap fuse libxml2 libcurl libgcc\
 libstdc++ rsync util-linux-misc &&\
 rm -rf /var/cache/apk/*
COPY --from=builder /usr/local/bin/webhook /usr/local/bin/webhook
COPY --from=builder /usr/local/bin/s3fs /usr/local/bin/s3fs
COPY entrypoint.sh /
COPY hooks/* ./hooks/
EXPOSE 9000
ENTRYPOINT ["/entrypoint.sh"]
CMD ["server"]
Again, we use a multi-stage build because in production we wanted to support a functionality that is not already on the official versions (streaming the command output as a response instead of waiting until the execution ends); this time we build the image applying the PATCH included on this pull request against a released version of the source instead of creating a fork. The entrypoint.sh script is used to generate the webhook configuration file for the existing hooks using environment variables (basically the WEBHOOK_WORKDIR and the *_TOKEN variables) and launch the webhook service:
entrypoint.sh
#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
WEBHOOK_BIN="$ WEBHOOK_BIN:-/webhook/hooks "
WEBHOOK_YML="$ WEBHOOK_YML:-/webhook/scs.yml "
WEBHOOK_OPTS="$ WEBHOOK_OPTS:--verbose "
# ---------
# FUNCTIONS
# ---------
print_du_yml()  
  cat <<EOF
- id: du
  execute-command: '$WEBHOOK_BIN/du.sh'
  command-working-directory: '$WORKDIR'
  response-headers:
  - name: 'Content-Type'
    value: 'application/json'
  http-methods: ['GET']
  include-command-output-in-response: true
  include-command-output-in-response-on-error: true
  pass-arguments-to-command:
  - source: 'url'
    name: 'path'
  pass-environment-to-command:
  - source: 'string'
    envname: 'OUTPUT_FORMAT'
    name: 'json'
EOF
 
print_hardlink_yml()  
  cat <<EOF
- id: hardlink
  execute-command: '$WEBHOOK_BIN/hardlink.sh'
  command-working-directory: '$WORKDIR'
  http-methods: ['GET']
  include-command-output-in-response: true
  include-command-output-in-response-on-error: true
EOF
 
print_s3sync_yml()  
  cat <<EOF
- id: s3sync
  execute-command: '$WEBHOOK_BIN/s3sync.sh'
  command-working-directory: '$WORKDIR'
  http-methods: ['POST']
  include-command-output-in-response: true
  include-command-output-in-response-on-error: true
  pass-environment-to-command:
  - source: 'payload'
    envname: 'AWS_KEY'
    name: 'aws.key'
  - source: 'payload'
    envname: 'AWS_SECRET_KEY'
    name: 'aws.secret_key'
  - source: 'payload'
    envname: 'S3_BUCKET'
    name: 's3.bucket'
  - source: 'payload'
    envname: 'S3_REGION'
    name: 's3.region'
  - source: 'payload'
    envname: 'S3_PATH'
    name: 's3.path'
  - source: 'payload'
    envname: 'SCS_PATH'
    name: 'scs.path'
  stream-command-output: true
EOF
 
print_token_yml()  
  if [ "$1" ]; then
    cat << EOF
  trigger-rule:
    match:
      type: 'value'
      value: '$1'
      parameter:
        source: 'header'
        name: 'X-Webhook-Token'
EOF
  fi
 
exec_webhook()  
  # Validate WORKDIR
  if [ -z "$WEBHOOK_WORKDIR" ]; then
    echo "Must define the WEBHOOK_WORKDIR variable!" >&2
    exit 1
  fi
  WORKDIR="$(realpath "$WEBHOOK_WORKDIR" 2>/dev/null)"   true
  if [ ! -d "$WORKDIR" ]; then
    echo "The WEBHOOK_WORKDIR '$WEBHOOK_WORKDIR' is not a directory!" >&2
    exit 1
  fi
  # Get TOKENS, if the DU_TOKEN or HARDLINK_TOKEN is defined that is used, if
  # not if the COMMON_TOKEN that is used and in other case no token is checked
  # (that is the default)
  DU_TOKEN="$ DU_TOKEN:-$COMMON_TOKEN "
  HARDLINK_TOKEN="$ HARDLINK_TOKEN:-$COMMON_TOKEN "
  S3_TOKEN="$ S3_TOKEN:-$COMMON_TOKEN "
  # Create webhook configuration
    
    print_du_yml
    print_token_yml "$DU_TOKEN"
    echo ""
    print_hardlink_yml
    print_token_yml "$HARDLINK_TOKEN"
    echo ""
    print_s3sync_yml
    print_token_yml "$S3_TOKEN"
   >"$WEBHOOK_YML"
  # Run the webhook command
  # shellcheck disable=SC2086
  exec webhook -hooks "$WEBHOOK_YML" $WEBHOOK_OPTS
 
# ----
# MAIN
# ----
case "$1" in
"server") exec_webhook ;;
*) exec "$@" ;;
esac
The entrypoint.sh script generates the configuration file for the webhook server calling functions that print a yaml section for each hook and optionally adds rules to validate access to them comparing the value of a X-Webhook-Token header against predefined values. The expected token values are taken from environment variables, we can define a token variable for each hook (DU_TOKEN, HARDLINK_TOKEN or S3_TOKEN) and a fallback value (COMMON_TOKEN); if no token variable is defined for a hook no check is done and everybody can call it. The Hook Definition documentation explains the options you can use for each hook, the ones we have right now do the following:
  • du: runs on the $WORKDIR directory, passes as first argument to the script the value of the path query parameter and sets the variable OUTPUT_FORMAT to the fixed value json (we use that to print the output of the script in JSON format instead of text).
  • hardlink: runs on the $WORKDIR directory and takes no parameters.
  • s3sync: runs on the $WORKDIR directory and sets a lot of environment variables from values read from the JSON encoded payload sent by the caller (all the values must be sent by the caller even if they are assigned an empty value, if they are missing the hook fails without calling the script); we also set the stream-command-output value to true to make the script show its output as it is working (we patched the webhook source to be able to use this option).

The du hook scriptThe du hook script code checks if the argument passed is a directory, computes its size using the du command and prints the results in text format or as a JSON dictionary:
hooks/du.sh
#!/bin/sh
set -e
# Script to print disk usage for a PATH inside the scs folder
# ---------
# FUNCTIONS
# ---------
print_error()  
  if [ "$OUTPUT_FORMAT" = "json" ]; then
    echo " \"error\":\"$*\" "
  else
    echo "$*" >&2
  fi
  exit 1
 
usage()  
  if [ "$OUTPUT_FORMAT" = "json" ]; then
    echo " \"error\":\"Pass arguments as '?path=XXX\" "
  else
    echo "Usage: $(basename "$0") PATH" >&2
  fi
  exit 1
 
# ----
# MAIN
# ----
if [ "$#" -eq "0" ]   [ -z "$1" ]; then
  usage
fi
if [ "$1" = "." ]; then
  DU_PATH="./"
else
  DU_PATH="$(find . -name "$1" -mindepth 1 -maxdepth 1)"   true
fi
if [ -z "$DU_PATH" ]   [ ! -d "$DU_PATH/." ]; then
  print_error "The provided PATH ('$1') is not a directory"
fi
# Print disk usage in bytes for the given PATH
OUTPUT="$(du -b -s "$DU_PATH")"
if [ "$OUTPUT_FORMAT" = "json" ]; then
  # Format output as  "path":"PATH","bytes":"BYTES" 
  echo "$OUTPUT"  
    sed -e "s%^\(.*\)\t.*/\(.*\)$% \"path\":\"\2\",\"bytes\":\"\1\" %"  
    tr -d '\n'
else
  # Print du output as is
  echo "$OUTPUT"
fi
# vim: ts=2:sw=2:et:ai:sts=2

The s3sync hook scriptThe s3sync hook script uses the s3fs tool to mount a bucket and synchronise data between a folder inside the bucket and a directory on the filesystem using rsync; all values needed to execute the task are taken from environment variables:
hooks/s3sync.sh
#!/bin/ash
set -euo pipefail
set -o errexit
set -o errtrace
# Functions
finish()  
  ret="$1"
  echo ""
  echo "Script exit code: $ret"
  exit "$ret"
 
# Check variables
if [ -z "$AWS_KEY" ]   [ -z "$AWS_SECRET_KEY" ]   [ -z "$S3_BUCKET" ]  
  [ -z "$S3_PATH" ]   [ -z "$SCS_PATH" ]; then
  [ "$AWS_KEY" ]   echo "Set the AWS_KEY environment variable"
  [ "$AWS_SECRET_KEY" ]   echo "Set the AWS_SECRET_KEY environment variable"
  [ "$S3_BUCKET" ]   echo "Set the S3_BUCKET environment variable"
  [ "$S3_PATH" ]   echo "Set the S3_PATH environment variable"
  [ "$SCS_PATH" ]   echo "Set the SCS_PATH environment variable"
  finish 1
fi
if [ "$S3_REGION" ] && [ "$S3_REGION" != "us-east-1" ]; then
  EP_URL="endpoint=$S3_REGION,url=https://s3.$S3_REGION.amazonaws.com"
else
  EP_URL="endpoint=us-east-1"
fi
# Prepare working directory
WORK_DIR="$(mktemp -p "$HOME" -d)"
MNT_POINT="$WORK_DIR/s3data"
PASSWD_S3FS="$WORK_DIR/.passwd-s3fs"
# Check the moutpoint
if [ ! -d "$MNT_POINT" ]; then
  mkdir -p "$MNT_POINT"
elif mountpoint "$MNT_POINT"; then
  echo "There is already something mounted on '$MNT_POINT', aborting!"
  finish 1
fi
# Create password file
touch "$PASSWD_S3FS"
chmod 0400 "$PASSWD_S3FS"
echo "$AWS_KEY:$AWS_SECRET_KEY" >"$PASSWD_S3FS"
# Mount s3 bucket as a filesystem
s3fs -o dbglevel=info,retries=5 -o "$EP_URL" -o "passwd_file=$PASSWD_S3FS" \
  "$S3_BUCKET" "$MNT_POINT"
echo "Mounted bucket '$S3_BUCKET' on '$MNT_POINT'"
# Remove the password file, just in case
rm -f "$PASSWD_S3FS"
# Check source PATH
ret="0"
SRC_PATH="$MNT_POINT/$S3_PATH"
if [ ! -d "$SRC_PATH" ]; then
  echo "The S3_PATH '$S3_PATH' can't be found!"
  ret=1
fi
# Compute SCS_UID & SCS_GID (by default based on the working directory owner)
SCS_UID="$ SCS_UID:=$(stat -c "%u" "." 2>/dev/null) "   true
SCS_GID="$ SCS_GID:=$(stat -c "%g" "." 2>/dev/null) "   true
# Check destination PATH
DST_PATH="./$SCS_PATH"
if [ "$ret" -eq "0" ] && [ -d "$DST_PATH" ]; then
  mkdir -p "$DST_PATH"   ret="$?"
fi
# Copy using rsync
if [ "$ret" -eq "0" ]; then
  rsync -rlptv --chown="$SCS_UID:$SCS_GID" --delete --stats \
    "$SRC_PATH/" "$DST_PATH/"   ret="$?"
fi
# Unmount the S3 bucket
umount -f "$MNT_POINT"
echo "Called umount for '$MNT_POINT'"
# Remove mount point dir
rmdir "$MNT_POINT"
# Remove WORK_DIR
rmdir "$WORK_DIR"
# We are done
finish "$ret"
# vim: ts=2:sw=2:et:ai:sts=2

Deployment objectsThe system is deployed as a StatefulSet with one replica. Our production deployment is done on AWS and to be able to scale we use EFS for our PersistenVolume; the idea is that the volume has no size limit, its AccessMode can be set to ReadWriteMany and we can mount it from multiple instances of the Pod without issues, even if they are in different availability zones. For development we use k3d and we are also able to scale the StatefulSet for testing because we use a ReadWriteOnce PVC, but it points to a hostPath that is backed up by a folder that is mounted on all the compute nodes, so in reality Pods in different k3d nodes use the same folder on the host.

secrets.yamlThe secrets file contains the files used by the mysecureshell container that can be generated using kubernetes pods as follows (we are only creating the scs user):
$ kubectl run "mysecureshell" --restart='Never' --quiet --rm --stdin \
  --image "stodh/mysecureshell:latest" -- gen-host-keys >"./host_keys.txt"
$ kubectl run "mysecureshell" --restart='Never' --quiet --rm --stdin \
  --image "stodh/mysecureshell:latest" -- gen-users-tar scs >"./users.tar"
Once we have the files we can generate the secrets.yaml file as follows:
$ tar xf ./users.tar user_keys.txt user_pass.txt
$ kubectl --dry-run=client -o yaml create secret generic "scs-secret" \
  --from-file="host_keys.txt=host_keys.txt" \
  --from-file="user_keys.txt=user_keys.txt" \
  --from-file="user_pass.txt=user_pass.txt" > ./secrets.yaml
The resulting secrets.yaml will look like the following file (the base64 would match the content of the files, of course):
secrets.yaml
apiVersion: v1
data:
  host_keys.txt: TWlt...
  user_keys.txt: c2Nz...
  user_pass.txt: c2Nz...
kind: Secret
metadata:
  creationTimestamp: null
  name: scs-secret

pvc.yamlThe persistent volume claim for a simple deployment (one with only one instance of the statefulSet) can be as simple as this:
pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: scs-pvc
  labels:
    app.kubernetes.io/name: scs
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 8Gi
On this definition we don t set the storageClassName to use the default one.

Volumes in our development environment (k3d)In our development deployment we create the following PersistentVolume as required by the Local Persistence Volume Static Provisioner (note that the /volumes/scs-pv has to be created by hand, in our k3d system we mount the same host directory on the /volumes path of all the nodes and create the scs-pv directory by hand before deploying the persistent volume):
k3d-pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: scs-pv
  labels:
    app.kubernetes.io/name: scs
spec:
  capacity:
    storage: 8Gi
  volumeMode: Filesystem
  accessModes:
  - ReadWriteOnce
  persistentVolumeReclaimPolicy: Delete
  claimRef:
    name: scs-pvc
  storageClassName: local-storage
  local:
    path: /volumes/scs-pv
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: node.kubernetes.io/instance-type
          operator: In
          values:
          - k3s
And to make sure that everything works as expected we update the PVC definition to add the right storageClassName:
k3d-pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: scs-pvc
  labels:
    app.kubernetes.io/name: scs
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 8Gi
  storageClassName: local-storage

Volumes in our production environment (aws)In the production deployment we don t create the PersistentVolume (we are using the aws-efs-csi-driver which supports Dynamic Provisioning) but we add the storageClassName (we set it to the one mapped to the EFS driver, i.e. efs-sc) and set ReadWriteMany as the accessMode:
efs-pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: scs-pvc
  labels:
    app.kubernetes.io/name: scs
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 8Gi
  storageClassName: efs-sc

statefulset.yamlThe definition of the statefulSet is as follows:
statefulset.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: scs
  labels:
    app.kubernetes.io/name: scs
spec:
  serviceName: scs
  replicas: 1
  selector:
    matchLabels:
      app: scs
  template:
    metadata:
      labels:
        app: scs
    spec:
      containers:
      - name: nginx
        image: stodh/nginx-scs:latest
        ports:
        - containerPort: 80
          name: http
        env:
        - name: AUTH_REQUEST_URI
          value: ""
        - name: HTML_ROOT
          value: /sftp/data
        volumeMounts:
        - mountPath: /sftp
          name: scs-datadir
      - name: mysecureshell
        image: stodh/mysecureshell:latest
        ports:
        - containerPort: 22
          name: ssh
        securityContext:
          capabilities:
            add:
            - IPC_OWNER
        env:
        - name: SFTP_UID
          value: '2020'
        - name: SFTP_GID
          value: '2020'
        volumeMounts:
        - mountPath: /secrets
          name: scs-file-secrets
          readOnly: true
        - mountPath: /sftp
          name: scs-datadir
      - name: webhook
        image: stodh/webhook-scs:latest
        securityContext:
          privileged: true
        ports:
        - containerPort: 9000
          name: webhook-http
        env:
        - name: WEBHOOK_WORKDIR
          value: /sftp/data/scs
        volumeMounts:
        - name: devfuse
          mountPath: /dev/fuse
        - mountPath: /sftp
          name: scs-datadir
      volumes:
      - name: devfuse
        hostPath:
          path: /dev/fuse
      - name: scs-file-secrets
        secret:
          secretName: scs-secrets
      - name: scs-datadir
        persistentVolumeClaim:
          claimName: scs-pvc
Notes about the containers:
  • nginx: As this is an example the web server is not using an AUTH_REQUEST_URI and uses the /sftp/data directory as the root of the web (to get to the files uploaded for the scs user we will need to use /scs/ as a prefix on the URLs).
  • mysecureshell: We are adding the IPC_OWNER capability to the container to be able to use some of the sftp-* commands inside it, but they are not really needed, so adding the capability is optional.
  • webhook: We are launching this container in privileged mode to be able to use the s3fs-fuse, as it will not work otherwise for now (see this kubernetes issue); if the functionality is not needed the container can be executed with regular privileges; besides, as we are not enabling public access to this service we don t define *_TOKEN variables (if required the values should be read from a Secret object).
Notes about the volumes:
  • the devfuse volume is only needed if we plan to use the s3fs command on the webhook container, if not we can remove the volume definition and its mounts.

service.yamlTo be able to access the different services on the statefulset we publish the relevant ports using the following Service object:
service.yaml
apiVersion: v1
kind: Service
metadata:
  name: scs-svc
  labels:
    app.kubernetes.io/name: scs
spec:
  ports:
  - name: ssh
    port: 22
    protocol: TCP
    targetPort: 22
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80
  - name: webhook-http
    port: 9000
    protocol: TCP
    targetPort: 9000
  selector:
    app: scs

ingress.yamlTo download the scs files from the outside we can add an ingress object like the following (the definition is for testing using the localhost name):
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: scs-ingress
  labels:
    app.kubernetes.io/name: scs
spec:
  ingressClassName: nginx
  rules:
  - host: 'localhost'
    http:
      paths:
      - path: /scs
        pathType: Prefix
        backend:
          service:
            name: scs-svc
            port:
              number: 80

DeploymentTo deploy the statefulSet we create a namespace and apply the object definitions shown before:
$ kubectl create namespace scs-demo
namespace/scs-demo created
$ kubectl -n scs-demo apply -f secrets.yaml
secret/scs-secrets created
$ kubectl -n scs-demo apply -f pvc.yaml
persistentvolumeclaim/scs-pvc created
$ kubectl -n scs-demo apply -f statefulset.yaml
statefulset.apps/scs created
$ kubectl -n scs-demo apply -f service.yaml
service/scs-svc created
$ kubectl -n scs-demo apply -f ingress.yaml
ingress.networking.k8s.io/scs-ingress created
Once the objects are deployed we can check that all is working using kubectl:
$ kubectl  -n scs-demo get all,secrets,ingress
NAME        READY   STATUS    RESTARTS   AGE
pod/scs-0   3/3     Running   0          24s
NAME            TYPE       CLUSTER-IP  EXTERNAL-IP  PORT(S)                  AGE
service/scs-svc ClusterIP  10.43.0.47  <none>       22/TCP,80/TCP,9000/TCP   21s

NAME                   READY   AGE
statefulset.apps/scs   1/1     24s
NAME                         TYPE                                  DATA   AGE
secret/default-token-mwcd7   kubernetes.io/service-account-token   3      53s
secret/scs-secrets           Opaque                                3      39s
NAME                                   CLASS  HOSTS      ADDRESS     PORTS   AGE
ingress.networking.k8s.io/scs-ingress  nginx  localhost  172.21.0.5  80      17s
At this point we are ready to use the system.

Usage examples

File uploadsAs previously mentioned in our system the idea is to use the sftp server from other Pods, but to test the system we are going to do a kubectl port-forward and connect to the server using our host client and the password we have generated (it is on the user_pass.txt file, inside the users.tar archive):
$ kubectl -n scs-demo port-forward service/scs-svc 2020:22 &
Forwarding from 127.0.0.1:2020 -> 22
Forwarding from [::1]:2020 -> 22
$ PF_PID=$!
$ sftp -P 2020 scs@127.0.0.1                                                 1
Handling connection for 2020
The authenticity of host '[127.0.0.1]:2020 ([127.0.0.1]:2020)' can't be \
  established.
ED25519 key fingerprint is SHA256:eHNwCnyLcSSuVXXiLKeGraw0FT/4Bb/yjfqTstt+088.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '[127.0.0.1]:2020' (ED25519) to the list of known \
  hosts.
scs@127.0.0.1's password: **********
Connected to 127.0.0.1.
sftp> ls -la
drwxr-xr-x    2 sftp     sftp         4096 Sep 25 14:47 .
dr-xr-xr-x    3 sftp     sftp         4096 Sep 25 14:36 ..
sftp> !date -R > /tmp/date.txt                                               2
sftp> put /tmp/date.txt .
Uploading /tmp/date.txt to /date.txt
date.txt                                      100%   32    27.8KB/s   00:00
sftp> ls -l
-rw-r--r--    1 sftp     sftp           32 Sep 25 15:21 date.txt
sftp> ln date.txt date.txt.1                                                 3
sftp> ls -l
-rw-r--r--    2 sftp     sftp           32 Sep 25 15:21 date.txt
-rw-r--r--    2 sftp     sftp           32 Sep 25 15:21 date.txt.1
sftp> put /tmp/date.txt date.txt.2                                           4
Uploading /tmp/date.txt to /date.txt.2
date.txt                                      100%   32    27.8KB/s   00:00
sftp> ls -l                                                                  5
-rw-r--r--    2 sftp     sftp           32 Sep 25 15:21 date.txt
-rw-r--r--    2 sftp     sftp           32 Sep 25 15:21 date.txt.1
-rw-r--r--    1 sftp     sftp           32 Sep 25 15:21 date.txt.2
sftp> exit
$ kill "$PF_PID"
[1]  + terminated  kubectl -n scs-demo port-forward service/scs-svc 2020:22
  1. We connect to the sftp service on the forwarded port with the scs user.
  2. We put a file we have created on the host on the directory.
  3. We do a hard link of the uploaded file.
  4. We put a second copy of the file we created locally.
  5. On the file list we can see that the two first files have two hardlinks

File retrievalsIf our ingress is configured right we can download the date.txt file from the URL http://localhost/scs/date.txt:
$ curl -s http://localhost/scs/date.txt
Sun, 25 Sep 2022 17:21:51 +0200

Use of the webhook containerTo finish this post we are going to show how we can call the hooks directly, from a CronJob and from a Job.

Direct script call (du)In our deployment the direct calls are done from other Pods, to simulate it we are going to do a port-forward and call the script with an existing PATH (the root directory) and a bad one:
$ kubectl -n scs-demo port-forward service/scs-svc 9000:9000 >/dev/null &
$ PF_PID=$!
$ JSON="$(curl -s "http://localhost:9000/hooks/du?path=.")"
$ echo $JSON
 "path":"","bytes":"4160" 
$ JSON="$(curl -s "http://localhost:9000/hooks/du?path=foo")"
$ echo $JSON
 "error":"The provided PATH ('foo') is not a directory" 
$ kill $PF_PID
As we only have files on the base directory we print the disk usage of the . PATH and the output is in json format because we export OUTPUT_FORMAT with the value json on the webhook configuration.

Jobs (s3sync)The following job can be used to synchronise the contents of a directory in a S3 bucket with the SCS Filesystem:
job.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: s3sync
  labels:
    cronjob: 's3sync'
spec:
  template:
    metadata:
      labels:
        cronjob: 's3sync'
    spec:
      containers:
      - name: s3sync-job
        image: alpine:latest
        command: 
        - "wget"
        - "-q"
        - "--header"
        - "Content-Type: application/json"
        - "--post-file"
        - "/secrets/s3sync.json"
        - "-O-"
        - "http://scs-svc:9000/hooks/s3sync"
        volumeMounts:
        - mountPath: /secrets
          name: job-secrets
          readOnly: true
      restartPolicy: Never
      volumes:
      - name: job-secrets
        secret:
          secretName: webhook-job-secrets
The file with parameters for the script must be something like this:
s3sync.json
 
  "aws":  
    "key": "********************",
    "secret_key": "****************************************"
   ,
  "s3":  
    "region": "eu-north-1",
    "bucket": "blogops-test",
    "path": "test"
   ,
  "scs":  
    "path": "test"
   
 
Once we have both files we can run the Job as follows:
$ kubectl -n scs-demo create secret generic webhook-job-secrets \            1
  --from-file="s3sync.json=s3sync.json"
secret/webhook-job-secrets created
$ kubectl -n scs-demo apply -f webhook-job.yaml                              2
job.batch/s3sync created
$ kubectl -n scs-demo get pods -l "cronjob=s3sync"                           3
NAME           READY   STATUS      RESTARTS   AGE
s3sync-zx2cj   0/1     Completed   0          12s
$ kubectl -n scs-demo logs s3sync-zx2cj                                      4
Mounted bucket 's3fs-test' on '/root/tmp.jiOjaF/s3data'
sending incremental file list
created directory ./test
./
kyso.png
Number of files: 2 (reg: 1, dir: 1)
Number of created files: 2 (reg: 1, dir: 1)
Number of deleted files: 0
Number of regular files transferred: 1
Total file size: 15,075 bytes
Total transferred file size: 15,075 bytes
Literal data: 15,075 bytes
Matched data: 0 bytes
File list size: 0
File list generation time: 0.147 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 15,183
Total bytes received: 74
sent 15,183 bytes  received 74 bytes  30,514.00 bytes/sec
total size is 15,075  speedup is 0.99
Called umount for '/root/tmp.jiOjaF/s3data'
Script exit code: 0
$ kubectl -n scs-demo delete -f webhook-job.yaml                             5
job.batch "s3sync" deleted
$ kubectl -n scs-demo delete secrets webhook-job-secrets                     6
secret "webhook-job-secrets" deleted
  1. Here we create the webhook-job-secrets secret that contains the s3sync.json file.
  2. This command runs the job.
  3. Checking the label cronjob=s3sync we get the Pods executed by the job.
  4. Here we print the logs of the completed job.
  5. Once we are finished we remove the Job.
  6. And also the secret.

Final remarksThis post has been longer than I expected, but I believe it can be useful for someone; in any case, next time I ll try to explain something shorter or will split it into multiple entries.

20 September 2022

Simon Josefsson: Privilege separation of GSS-API credentials for Apache

To protect web resources with Kerberos you may use Apache HTTPD with mod_auth_gssapi however, all web scripts (e.g., PHP) run under Apache will have access to the Kerberos long-term symmetric secret credential (keytab). If someone can get it, they can impersonate your server, which is bad. The gssproxy project makes it possible to introduce privilege separation to reduce the attack surface. There is a tutorial for RPM-based distributions (Fedora, RHEL, AlmaLinux, etc), but I wanted to get this to work on a DPKG-based distribution (Debian, Ubuntu, Trisquel, PureOS, etc) and found it worthwhile to document the process. I m using Ubuntu 22.04 below, but have tested it on Debian 11 as well. I have adopted the gssproxy package in Debian, and testing this setup is part of the scripted autopkgtest/debci regression testing. First install the required packages:
root@foo:~# apt-get update
root@foo:~# apt-get install -y apache2 libapache2-mod-auth-gssapi gssproxy curl
This should give you a working and running web server. Verify it is operational under the proper hostname, I ll use foo.sjd.se in this writeup.
root@foo:~# curl --head http://foo.sjd.se/
HTTP/1.1 200 OK
The next step is to create a keytab containing the Kerberos V5 secrets for your host, the exact steps depends on your environment (usually kadmin ktadd or ipa-getkeytab), but use the string HTTP/foo.sjd.se and then confirm using something like the following.
root@foo:~# ls -la /etc/gssproxy/httpd.keytab
-rw------- 1 root root 176 Sep 18 06:44 /etc/gssproxy/httpd.keytab
root@foo:~# klist -k /etc/gssproxy/httpd.keytab -e
Keytab name: FILE:/etc/gssproxy/httpd.keytab
KVNO Principal
---- --------------------------------------------------------------------------
   2 HTTP/foo.sjd.se@GSSPROXY.EXAMPLE.ORG (aes256-cts-hmac-sha1-96) 
   2 HTTP/foo.sjd.se@GSSPROXY.EXAMPLE.ORG (aes128-cts-hmac-sha1-96) 
root@foo:~# 
The file should be owned by root and not be in the default /etc/krb5.keytab location, so Apache s libapache2-mod-auth-gssapi will have to use gssproxy to use it.

Then configure gssproxy to find the credential and use it with Apache.
root@foo:~# cat<<EOF > /etc/gssproxy/80-httpd.conf
[service/HTTP]
mechs = krb5
cred_store = keytab:/etc/gssproxy/httpd.keytab
cred_store = ccache:/var/lib/gssproxy/clients/krb5cc_%U
euid = www-data
process = /usr/sbin/apache2
EOF
For debugging, it may be useful to enable more gssproxy logging:
root@foo:~# cat<<EOF > /etc/gssproxy/gssproxy.conf
[gssproxy]
debug_level = 1
EOF
root@foo:~#
Restart gssproxy so it finds the new configuration, and monitor syslog as follows:
root@foo:~# tail -F /var/log/syslog &
root@foo:~# systemctl restart gssproxy
You should see something like this in the log file:
Sep 18 07:03:15 foo gssproxy[4076]: [2022/09/18 05:03:15]: Exiting after receiving a signal
Sep 18 07:03:15 foo systemd[1]: Stopping GSSAPI Proxy Daemon
Sep 18 07:03:15 foo systemd[1]: gssproxy.service: Deactivated successfully.
Sep 18 07:03:15 foo systemd[1]: Stopped GSSAPI Proxy Daemon.
Sep 18 07:03:15 foo gssproxy[4092]: [2022/09/18 05:03:15]: Debug Enabled (level: 1)
Sep 18 07:03:15 foo systemd[1]: Starting GSSAPI Proxy Daemon
Sep 18 07:03:15 foo gssproxy[4093]: [2022/09/18 05:03:15]: Kernel doesn't support GSS-Proxy (can't open /proc/net/rpc/use-gss-proxy: 2 (No such file or directory))
Sep 18 07:03:15 foo gssproxy[4093]: [2022/09/18 05:03:15]: Problem with kernel communication! NFS server will not work
Sep 18 07:03:15 foo systemd[1]: Started GSSAPI Proxy Daemon.
Sep 18 07:03:15 foo gssproxy[4093]: [2022/09/18 05:03:15]: Initialization complete.
The NFS-related errors is due to a default gssproxy configuration file, it is harmless and if you don t use NFS with GSS-API you can silence it like this:
root@foo:~# rm /etc/gssproxy/24-nfs-server.conf
root@foo:~# systemctl try-reload-or-restart gssproxy
The log should now indicate that it loaded the keytab:
Sep 18 07:18:59 foo systemd[1]: Reloading GSSAPI Proxy Daemon 
Sep 18 07:18:59 foo gssproxy[4182]: [2022/09/18 05:18:59]: Received SIGHUP; re-reading config.
Sep 18 07:18:59 foo gssproxy[4182]: [2022/09/18 05:18:59]: Service: HTTP, Keytab: /etc/gssproxy/httpd.keytab, Enctype: 18
Sep 18 07:18:59 foo gssproxy[4182]: [2022/09/18 05:18:59]: New config loaded successfully.
Sep 18 07:18:59 foo systemd[1]: Reloaded GSSAPI Proxy Daemon.
To instruct Apache or actually, the MIT Kerberos V5 GSS-API library used by mod_auth_gssap loaded by Apache to use gssproxy instead of using /etc/krb5.keytab as usual, Apache needs to be started in an environment that has GSS_USE_PROXY=1 set. The background is covered by the gssproxy-mech(8) man page and explained by the gssproxy README.

When systemd is used the following can be used to set the environment variable, note the final command to reload systemd.
root@foo:~# mkdir -p /etc/systemd/system/apache2.service.d
root@foo:~# cat<<EOF > /etc/systemd/system/apache2.service.d/gssproxy.conf
[Service]
Environment=GSS_USE_PROXY=1
EOF
root@foo:~# systemctl daemon-reload
The next step is to configure a GSS-API protected Apache resource:
root@foo:~# cat<<EOF > /etc/apache2/conf-available/private.conf
<Location /private>
  AuthType GSSAPI
  AuthName "GSSAPI Login"
  Require valid-user
</Location>
Enable the configuration and restart Apache the suggested use of reload is not sufficient, because then it won t be restarted with the newly introduced GSS_USE_PROXY variable. This just applies to the first time, after the first restart you may use reload again.
root@foo:~# a2enconf private
Enabling conf private.
To activate the new configuration, you need to run:
systemctl reload apache2
root@foo:~# systemctl restart apache2
When you have debug messages enabled, the log may look like this:
Sep 18 07:32:23 foo systemd[1]: Stopping The Apache HTTP Server 
Sep 18 07:32:23 foo gssproxy[4182]: [2022/09/18 05:32:23]: Client [2022/09/18 05:32:23]: (/usr/sbin/apache2) [2022/09/18 05:32:23]: connected (fd = 10)[2022/09/18 05:32:23]: (pid = 4651) (uid = 0) (gid = 0)[2022/09/18 05:32:23]:
Sep 18 07:32:23 foo gssproxy[4182]: message repeated 4 times: [ [2022/09/18 05:32:23]: Client [2022/09/18 05:32:23]: (/usr/sbin/apache2) [2022/09/18 05:32:23]: connected (fd = 10)[2022/09/18 05:32:23]: (pid = 4651) (uid = 0) (gid = 0)[2022/09/18 05:32:23]:]
Sep 18 07:32:23 foo systemd[1]: apache2.service: Deactivated successfully.
Sep 18 07:32:23 foo systemd[1]: Stopped The Apache HTTP Server.
Sep 18 07:32:23 foo systemd[1]: Starting The Apache HTTP Server
Sep 18 07:32:23 foo gssproxy[4182]: [2022/09/18 05:32:23]: Client [2022/09/18 05:32:23]: (/usr/sbin/apache2) [2022/09/18 05:32:23]: connected (fd = 10)[2022/09/18 05:32:23]: (pid = 4657) (uid = 0) (gid = 0)[2022/09/18 05:32:23]:
root@foo:~# Sep 18 07:32:23 foo gssproxy[4182]: message repeated 8 times: [ [2022/09/18 05:32:23]: Client [2022/09/18 05:32:23]: (/usr/sbin/apache2) [2022/09/18 05:32:23]: connected (fd = 10)[2022/09/18 05:32:23]: (pid = 4657) (uid = 0) (gid = 0)[2022/09/18 05:32:23]:]
Sep 18 07:32:23 foo systemd[1]: Started The Apache HTTP Server.
Finally, set up a dummy test page on the server:
root@foo:~# echo OK > /var/www/html/private
To verify that the server is working properly you may acquire tickets locally and then use curl to retrieve the GSS-API protected resource. The "--negotiate" enables SPNEGO and "--user :" asks curl to use username from the environment.
root@foo:~# klist
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: jas@GSSPROXY.EXAMPLE.ORG
Valid starting Expires Service principal
09/18/22 07:40:37 09/19/22 07:40:37 krbtgt/GSSPROXY.EXAMPLE.ORG@GSSPROXY.EXAMPLE.ORG
root@foo:~# curl --negotiate --user : http://foo.sjd.se/private
OK
root@foo:~#
The log should contain something like this:
Sep 18 07:56:00 foo gssproxy[4872]: [2022/09/18 05:56:00]: Client [2022/09/18 05:56:00]: (/usr/sbin/apache2) [2022/09/18 05:56:00]: connected (fd = 10)[2022/09/18 05:56:00]: (pid = 5042) (uid = 33) (gid = 33)[2022/09/18 05:56:00]:
Sep 18 07:56:00 foo gssproxy[4872]: [CID 10][2022/09/18 05:56:00]: gp_rpc_execute: executing 6 (GSSX_ACQUIRE_CRED) for service "HTTP", euid: 33,socket: (null)
Sep 18 07:56:00 foo gssproxy[4872]: [CID 10][2022/09/18 05:56:00]: gp_rpc_execute: executing 6 (GSSX_ACQUIRE_CRED) for service "HTTP", euid: 33,socket: (null)
Sep 18 07:56:00 foo gssproxy[4872]: [CID 10][2022/09/18 05:56:00]: gp_rpc_execute: executing 1 (GSSX_INDICATE_MECHS) for service "HTTP", euid: 33,socket: (null)
Sep 18 07:56:00 foo gssproxy[4872]: [CID 10][2022/09/18 05:56:00]: gp_rpc_execute: executing 6 (GSSX_ACQUIRE_CRED) for service "HTTP", euid: 33,socket: (null)
Sep 18 07:56:00 foo gssproxy[4872]: [CID 10][2022/09/18 05:56:00]: gp_rpc_execute: executing 9 (GSSX_ACCEPT_SEC_CONTEXT) for service "HTTP", euid: 33,socket: (null)
The Apache log will look like this, notice the authenticated username shown.
127.0.0.1 - jas@GSSPROXY.EXAMPLE.ORG [18/Sep/2022:07:56:00 +0200] "GET /private HTTP/1.1" 200 481 "-" "curl/7.81.0"
Congratulations, and happy hacking!

Matthew Garrett: Handling WebAuthn over remote SSH connections

Being able to SSH into remote machines and do work there is great. Using hardware security tokens for 2FA is also great. But trying to use them both at the same time doesn't work super well, because if you hit a WebAuthn request on the remote machine it doesn't matter how much you mash your token - it's not going to work.

But could it?

The SSH agent protocol abstracts key management out of SSH itself and into a separate process. When you run "ssh-add .ssh/id_rsa", that key is being loaded into the SSH agent. When SSH wants to use that key to authenticate to a remote system, it asks the SSH agent to perform the cryptographic signatures on its behalf. SSH also supports forwarding the SSH agent protocol over SSH itself, so if you SSH into a remote system then remote clients can also access your keys - this allows you to bounce through one remote system into another without having to copy your keys to those remote systems.

More recently, SSH gained the ability to store SSH keys on hardware tokens such as Yubikeys. If configured appropriately, this means that even if you forward your agent to a remote site, that site can't do anything with your keys unless you physically touch the token. But out of the box, this is only useful for SSH keys - you can't do anything else with this support.

Well, that's what I thought, at least. And then I looked at the code and realised that SSH is communicating with the security tokens using the same library that a browser would, except it ensures that any signature request starts with the string "ssh:" (which a genuine WebAuthn request never will). This constraint can actually be disabled by passing -O no-restrict-websafe to ssh-agent, except that was broken until this weekend. But let's assume there's a glorious future where that patch gets backported everywhere, and see what we can do with it.

First we need to load the key into the security token. For this I ended up hacking up the Go SSH agent support. Annoyingly it doesn't seem to be possible to make calls to the agent without going via one of the exported methods here, so I don't think this logic can be implemented without modifying the agent module itself. But this is basically as simple as adding another key message type that looks something like:
type ecdsaSkKeyMsg struct  
       Type        string  sshtype:"17 25" 
       Curve       string
       PubKeyBytes []byte
       RpId        string
       Flags       uint8
       KeyHandle   []byte
       Reserved    []byte
       Comments    string
       Constraints []byte  ssh:"rest" 
 
Where Type is ssh.KeyAlgoSKECDSA256, Curve is "nistp256", RpId is the identity of the relying party (eg, "webauthn.io"), Flags is 0x1 if you want the user to have to touch the key, KeyHandle is the hardware token's representation of the key (basically an opaque blob that's sufficient for the token to regenerate the keypair - this is generally stored by the remote site and handed back to you when it wants you to authenticate). The other fields can be ignored, other than PubKeyBytes, which is supposed to be the public half of the keypair.

This causes an obvious problem. We have an opaque blob that represents a keypair. We don't have the public key. And OpenSSH verifies that PubKeyByes is a legitimate ecdsa public key before it'll load the key. Fortunately it only verifies that it's a legitimate ecdsa public key, and does nothing to verify that it's related to the private key in any way. So, just generate a new ECDSA key (ecdsa.GenerateKey(elliptic.P256(), rand.Reader)) and marshal it ( elliptic.Marshal(ecKey.Curve, ecKey.X, ecKey.Y)) and we're good. Pass that struct to ssh.Marshal() and then make an agent call.

Now you can use the standard agent interfaces to trigger a signature event. You want to pass the raw challenge (not the hash of the challenge!) - the SSH code will do the hashing itself. If you're using agent forwarding this will be forwarded from the remote system to your local one, and your security token should start blinking - touch it and you'll get back an ssh.Signature blob. ssh.Unmarshal() the Blob member to a struct like
type ecSig struct  
        R *big.Int
        S *big.Int
 
and then ssh.Unmarshal the Rest member to
type authData struct  
        Flags    uint8
        SigCount uint32
 
The signature needs to be converted back to a DER-encoded ASN.1 structure (eg,
var b cryptobyte.Builder
b.AddASN1(asn1.SEQUENCE, func(b *cryptobyte.Builder)  
        b.AddASN1BigInt(ecSig.R)
        b.AddASN1BigInt(ecSig.S)
 )
signatureDER, _ := b.Bytes()
, and then you need to construct the Authenticator Data structure. For this, take the RpId used earlier and generate the sha256. Append the one byte Flags variable, and then convert SigCount to big endian and append those 4 bytes. You should now have a 37 byte structure. This needs to be CBOR encoded (I used github.com/fxamacker/cbor and just called cbor.Marshal(data, cbor.EncOptions )).

Now base64 encode the sha256 of the challenge data, the DER-encoded signature and the CBOR-encoded authenticator data and you've got everything you need to provide to the remote site to satisfy the challenge.

There are alternative approaches - you can use USB/IP to forward the hardware token directly to the remote system. But that means you can't use it locally, so it's less than ideal. Or you could implement a proxy that communicates with the key locally and have that tunneled through to the remote host, but at that point you're just reinventing ssh-agent.

And you should bear in mind that the default behaviour of blocking this sort of request is for a good reason! If someone is able to compromise a remote system that you're SSHed into, they can potentially trick you into hitting the key to sign a request they've made on behalf of an arbitrary site. Obviously they could do the same without any of this if they've compromised your local system, but there is some additional risk to this. It would be nice to have sensible MAC policies that default-denied access to the SSH agent socket and only allowed trustworthy binaries to do so, or maybe have some sort of reasonable flatpak-style portal to gate access. For my threat model I think it's a worthwhile security tradeoff, but you should evaluate that carefully yourself.

Anyway. Now to figure out whether there's a reasonable way to get browsers to work with this.

comment count unavailable comments

6 September 2022

Shirish Agarwal: Debian on Phone

History Before I start, the game I was talking about is called Cell To Singularity. Now I haven t gone much in the game as I have shared but think that the Singularity it refers to is the Technological Singularity that people think will happen. Whether that will happen or not is open to debate to one and all. This is going to be a bit long one. Confession Time :- When I was sharing in the blog post, I had no clue that we actually had sessions on it in this year s Debconf. I just saw the schedule yesterday and then came to know. Then I saw Guido s two talks, one at Debconf as well as one as Froscon. In fact, saw the Froscon talk first, and then the one at Debconf. Both the talks are nearly the same except for a thing here or a thing there. Now because I was not there so my understanding and knowledge would be disadvantageously asymmetrical to Guido and others who were there and could talk and share more. Having a Debian mobile or Debian on the mobile could also make Debian more popular and connectable to the masses, one of the things that were not pointed out in the Debian India BOF sadly. At the same time, there are some facts that are not on the table and hence not thought about. Being a B.Com person, I have been following not just the technical but also how the economics work and smartphone penetration in India is pretty low or historically been very low, say around 3-4% while the majority that people use, almost 90-95% of the market uses what are called non-smartphones or dumbphones. Especially during the pandemic and even after that the dumbphones market actually went up while smartphones stagnated and even came down. There is a lot of inventory at most of the dealers that they can t get rid of. From a dealer perspective, it probably makes more sense to buy and sell dumbphones more in number as the turnaround of capital is much faster and easier than for smartphones. I have seen people spend a number of hours and rightly so in order to make their minds up on a smartphone while for a dumbphone, it is a 10-minute thing. Ask around, figure out who is selling at the cheapest, and just buy. Most of these low-end phones are coming from China. In fact, even in the middle and getting even into smartphones, the Chinese are the masters from whom we buy, even as they have occupied Indian territory. In the top five, Samsung comes at number three of four (sharing about Samsung as a fan and having used them.) even though battery times are atrocious, especially with Android 12L. The only hope that most of the smartphone manufacturers have is lowering the sticker prices and hoping that 5G Adoption picks up and that is what they are betting on but that comes with its own share of drawbacks as can be seen.

GNOME, MATE, memory leaks, Payments FWIW, while I do have GNOME and do use a couple of tools from the GNOME stack, I hate GNOME with a passion. I have been a mate user for almost a decade now and really love the simplicity that mate has vis-a-vis GNOME. And with each release, MATE has only become better. So, it would be nice if we can have MATE on the mobile phone. How adaptive the apps might be on the smaller area, I dunno. It would be interesting to find out if and how people are looking at debugging memory leaks on mobile phones. Although finding memory leaks on any platform is good, finding them and fixing them on a mobile phone is pretty much critical as most phones have fixed & relatively small amounts of memory and it is and can get quickly exhausted. One of the things that were asked in the Q&A was about payments. The interesting thing is both UK and India are the same or markedly similar in regard as far as contactless payments being concerned. What most Indians have or use is basically UPI which is basically backed by your bank. Unlike in some other countries where you have a selection of wallets and even temporary/permanent virtual accounts whereby you can minimize your risks in case your mobile gets stolen or something, here we don t have that. There are three digital wallets that I know Paytm Not used (have heard it s creepy, but don t really know), Google pay (Unfortunately, this is the one I use, they bought multiple features, and in the last couple of years have really taken the game away from Paytm but also creepy.). The last one is Samsung Pay (haven t really used it as their find my phone app. always crashes, dunno how it is supposed to work.) But I do find that the apps. are vulnerable. Every day there is some or other news of fraud happening. Previously, only States like Bihar and Jharkhand used to be infamous for cybercrime as a hub, but now even States like Andhra Pradesh have joined and surpassed them :(. People have lost lakhs and crores, this is just a few days back. Some more info. on UPI can be found here and GitHub has a few implementation examples that anybody could look at and run away with it.

Balancing on three things For any new mobile phone to crack the market, it has to balance three things. One, achieve economies of scale. Unless, that is not taken care of or done, however good or bad the product might be, it remains a niche and dies after some time. While Guido shared about Openmoko and N900, one of the more interesting bits from a user perspective at least was the OLPC project. There are many nuances that the short article didn t go through. While I can t say for other countries, at least in India, no education initiative happens without corruption. And perhaps Nicholas s hands were tied while other manufacturers would and could do to achieve their sales targets. In India, it flopped because there was no way for volunteers to buy or get OLPC unless they were part of a school or college. There was some traction in FOSS communities, but that died down once OLPC did the partnership with MS-Windows, and proverbially broke the camel s back. FWIW, I think the idea, the concept, and even the machine were far ahead of their time. The other two legs are support and Warranty Without going into any details, I can share and tell there were quite a few OLPC type attempts using conventional laptops or using Android and FOSS or others or even using one of the mainstream distributions but the problems have always been polishing, training and support. Guido talked about privacy as a winning feature but fails to take into account that people want to know that their privacy isn t being violated. If a mobile phone answers to Hey Google does it mean it was passively gathering, storing, and sending info to third parties, we just don t know. The mobile phone could be part of the right to repair profile while at the same time it can force us to ask many questions about the way things currently are and going to be. Six months down the line all the flagships of all companies are working on being able to take and share through satellites (Satellite Internet) and perhaps maybe a few non-flagships. Of course, if you are going to use a satellite, then you are going to drain that much more quickly. In all and every event there are always gonna be tradeoffs. The Debian-mobile mailing list doesn t seem to have many takers. The latest I could find there is written by Paul Wise. I am in a similar boat (Samsung; SM-M526B; Lahaina; arm64-v8a) v12. It is difficult to know which release would work on your machine, make sure that the building from the source is not tainted and pristine and needs a way to backup and restore if you need to. I even tried installing GNURoot Debian and the Xserver alternative they had shared but was unable to use the touch interface on the fakeroot instance  . The system talks about a back key but what back key I have no clue.

Precursor Events Debconf 2023 As far as precursor events are concerned before Debconf 23 in India, all the festivals that we have could be used to showcase Debian. In fact, the ongoing Ganesh Chaturthi would have been the perfect way to showcase Debian and apps. according to the audience. Even the festival of Durga Puja, Diwali etc. can be used. When commercial organizations use the same festivals, why can t we? What perhaps we would need to figure out is the funding part as well as getting permissions from Municipal authorities. One of the things for e.g. that we could do is buy either a permanent 24 monitor or a 34 TV and use that to display Debian and apps. The bigger, the better. Something that we could use day to day and also is used for events. This would require significant amounts of energy so we could approach companies, small businesses and individuals both for volunteering as well as helping out with funding. Somebody asked how we could do online stuff and why it is somewhat boring. What could be done for e.g. instead of 4-5 hrs. of things, break it into manageable 45 minute pieces. 4-5 hrs. is long and is gonna fatigue the best of people. Make it into 45-minute negotiable chunks, and intersphere it with jokes, hacks, anecdotes, and war stories. People do not like or want to be talked down to but rather converse. One of the things that I saw many of the artists do is have shows and limit the audience to 20-24 people on zoom call or whatever videoconferencing system you have and play with them. The passive audience enjoys the play between the standup guy and the crowd he works on, some of them may be known to him personally so he can push that envelope a bit more. The same thing can be applied here. Share the passion, and share why we are doing something. For e.g. you could do smem -t -k less and give a whole talk about how memory is used and freed during a session, how are things different on desktop and ARM as far as memory architecture is concerned (if there is). What is being done on the hardware side, what is on the software side and go on and on. Then share about troubleshooting applications. Valgrind is super slow and makes life hell, is there some better app ? Doesn t matter if you are a front-end or a back-end developer you need to know this and figure out the best way to deal with in your app/program. That would have lot of value. And this is just an e.g. to help trigger more ideas from the community. I am sure others probably have more fun ideas as to what can be done. I am stopping here now otherwise would just go on, till later. Feel free to comment, feedback. Hope it generates some more thinking and excitement on the grey cells.

30 August 2022

John Goerzen: The PC & Internet Revolution in Rural America

Inspired by several others (such as Alex Schroeder s post and Szcze uja s prompt), as well as a desire to get this down for my kids, I figure it s time to write a bit about living through the PC and Internet revolution where I did: outside a tiny town in rural Kansas. And, as I ve been back in that same area for the past 15 years, I reflect some on the challenges that continue to play out. Although the stories from the others were primarily about getting online, I want to start by setting some background. Those of you that didn t grow up in the same era as I did probably never realized that a typical business PC setup might cost $10,000 in today s dollars, for instance. So let me start with the background.

Nothing was easy This story begins in the 1980s. Somewhere around my Kindergarten year of school, around 1985, my parents bought a TRS-80 Color Computer 2 (aka CoCo II). It had 64K of RAM and used a TV for display and sound. This got you the computer. It didn t get you any disk drive or anything, no joysticks (required by a number of games). So whenever the system powered down, or it hung and you had to power cycle it a frequent event you d lose whatever you were doing and would have to re-enter the program, literally by typing it in. The floppy drive for the CoCo II cost more than the computer, and it was quite common for people to buy the computer first and then the floppy drive later when they d saved up the money for that. I particularly want to mention that computers then didn t come with a modem. What would be like buying a laptop or a tablet without wifi today. A modem, which I ll talk about in a bit, was another expensive accessory. To cobble together a system in the 80s that was capable of talking to others with persistent storage (floppy, or hard drive), screen, keyboard, and modem would be quite expensive. Adjusted for inflation, if you re talking a PC-style device (a clone of the IBM PC that ran DOS), this would easily be more expensive than the Macbook Pros of today. Few people back in the 80s had a computer at home. And the portion of those that had even the capability to get online in a meaningful way was even smaller. Eventually my parents bought a PC clone with 640K RAM and dual floppy drives. This was primarily used for my mom s work, but I did my best to take it over whenever possible. It ran DOS and, despite its monochrome screen, was generally a more capable machine than the CoCo II. For instance, it supported lowercase. (I m not even kidding; the CoCo II pretty much didn t.) A while later, they purchased a 32MB hard drive for it what luxury! Just getting a machine to work wasn t easy. Say you d bought a PC, and then bought a hard drive, and a modem. You didn t just plug in the hard drive and it would work. You would have to fight it every step of the way. The BIOS and DOS partition tables of the day used a cylinder/head/sector method of addressing the drive, and various parts of that those addresses had too few bits to work with the big drives of the day above 20MB. So you would have to lie to the BIOS and fdisk in various ways, and sort of work out how to do it for each drive. For each peripheral serial port, sound card (in later years), etc., you d have to set jumpers for DMA and IRQs, hoping not to conflict with anything already in the system. Perhaps you can now start to see why USB and PCI were so welcomed.

Sharing and finding resources Despite the two computers in our home, it wasn t as if software written on one machine just ran on another. A lot of software for PC clones assumed a CGA color display. The monochrome HGC in our PC wasn t particularly compatible. You could find a TSR program to emulate the CGA on the HGC, but it wasn t particularly stable, and there s only so much you can do when a program that assumes color displays on a monitor that can only show black, dark amber, or light amber. So I d periodically get to use other computers most commonly at an office in the evening when it wasn t being used. There were some local computer clubs that my dad took me to periodically. Software was swapped back then; disks copied, shareware exchanged, and so forth. For me, at least, there was no online to download software from, and selling software over the Internet wasn t a thing at all.

Three Different Worlds There were sort of three different worlds of computing experience in the 80s:
  1. Home users. Initially using a wide variety of software from Apple, Commodore, Tandy/RadioShack, etc., but eventually coming to be mostly dominated by IBM PC clones
  2. Small and mid-sized business users. Some of them had larger minicomputers or small mainframes, but most that I had contact with by the early 90s were standardized on DOS-based PCs. More advanced ones had a network running Netware, most commonly. Networking hardware and software was generally too expensive for home users to use in the early days.
  3. Universities and large institutions. These are the places that had the mainframes, the earliest implementations of TCP/IP, the earliest users of UUCP, and so forth.
The difference between the home computing experience and the large institution experience were vast. Not only in terms of dollars the large institution hardware could easily cost anywhere from tens of thousands to millions of dollars but also in terms of sheer resources required (large rooms, enormous power circuits, support staff, etc). Nothing was in common between them; not operating systems, not software, not experience. I was never much aware of the third category until the differences started to collapse in the mid-90s, and even then I only was exposed to it once the collapse was well underway. You might say to me, Well, Google certainly isn t running what I m running at home! And, yes of course, it s different. But fundamentally, most large datacenters are running on x86_64 hardware, with Linux as the operating system, and a TCP/IP network. It s a different scale, obviously, but at a fundamental level, the hardware and operating system stack are pretty similar to what you can readily run at home. Back in the 80s and 90s, this wasn t the case. TCP/IP wasn t even available for DOS or Windows until much later, and when it was, it was a clunky beast that was difficult. One of the things Kevin Driscoll highlights in his book called Modem World see my short post about it is that the history of the Internet we usually receive is focused on case 3: the large institutions. In reality, the Internet was and is literally a network of networks. Gateways to and from Internet existed from all three kinds of users for years, and while TCP/IP ultimately won the battle of the internetworking protocol, the other two streams of users also shaped the Internet as we now know it. Like many, I had no access to the large institution networks, but as I ve been reflecting on my experiences, I ve found a new appreciation for the way that those of us that grew up with primarily home PCs shaped the evolution of today s online world also.

An Era of Scarcity I should take a moment to comment about the cost of software back then. A newspaper article from 1985 comments that WordPerfect, then the most powerful word processing program, sold for $495 (or $219 if you could score a mail order discount). That s $1360/$600 in 2022 money. Other popular software, such as Lotus 1-2-3, was up there as well. If you were to buy a new PC clone in the mid to late 80s, it would often cost $2000 in 1980s dollars. Now add a printer a low-end dot matrix for $300 or a laser for $1500 or even more. A modem: another $300. So the basic system would be $3600, or $9900 in 2022 dollars. If you wanted a nice printer, you re now pushing well over $10,000 in 2022 dollars. You start to see one barrier here, and also why things like shareware and piracy if it was indeed even recognized as such were common in those days. So you can see, from a home computer setup (TRS-80, Commodore C64, Apple ][, etc) to a business-class PC setup was an order of magnitude increase in cost. From there to the high-end minis/mainframes was another order of magnitude (at least!) increase. Eventually there was price pressure on the higher end and things all got better, which is probably why the non-DOS PCs lasted until the early 90s.

Increasing Capabilities My first exposure to computers in school was in the 4th grade, when I would have been about 9. There was a single Apple ][ machine in that room. I primarily remember playing Oregon Trail on it. The next year, the school added a computer lab. Remember, this is a small rural area, so each graduating class might have about 25 people in it; this lab was shared by everyone in the K-8 building. It was full of some flavor of IBM PS/2 machines running DOS and Netware. There was a dedicated computer teacher too, though I think she was a regular teacher that was given somewhat minimal training on computers. We were going to learn typing that year, but I did so well on the very first typing program that we soon worked out that I could do programming instead. I started going to school early these machines were far more powerful than the XT at home and worked on programming projects there. Eventually my parents bought me a Gateway 486SX/25 with a VGA monitor and hard drive. Wow! This was a whole different world. It may have come with Windows 3.0 or 3.1 on it, but I mainly remember running OS/2 on that machine. More on that below.

Programming That CoCo II came with a BASIC interpreter in ROM. It came with a large manual, which served as a BASIC tutorial as well. The BASIC interpreter was also the shell, so literally you could not use the computer without at least a bit of BASIC. Once I had access to a DOS machine, it also had a basic interpreter: GW-BASIC. There was a fair bit of software written in BASIC at the time, but most of the more advanced software wasn t. I wondered how these .EXE and .COM programs were written. I could find vague references to DEBUG.EXE, assemblers, and such. But it wasn t until I got a copy of Turbo Pascal that I was able to do that sort of thing myself. Eventually I got Borland C++ and taught myself C as well. A few years later, I wanted to try writing GUI programs for Windows, and bought Watcom C++ much cheaper than the competition, and it could target Windows, DOS (and I think even OS/2). Notice that, aside from BASIC, none of this was free, and none of it was bundled. You couldn t just download a C compiler, or Python interpreter, or whatnot back then. You had to pay for the ability to write any kind of serious code on the computer you already owned.

The Microsoft Domination Microsoft came to dominate the PC landscape, and then even the computing landscape as a whole. IBM very quickly lost control over the hardware side of PCs as Compaq and others made clones, but Microsoft has managed in varying degrees even to this day to keep a stranglehold on the software, and especially the operating system, side. Yes, there was occasional talk of things like DR-DOS, but by and large the dominant platform came to be the PC, and if you had a PC, you ran DOS (and later Windows) from Microsoft. For awhile, it looked like IBM was going to challenge Microsoft on the operating system front; they had OS/2, and when I switched to it sometime around the version 2.1 era in 1993, it was unquestionably more advanced technically than the consumer-grade Windows from Microsoft at the time. It had Internet support baked in, could run most DOS and Windows programs, and had introduced a replacement for the by-then terrible FAT filesystem: HPFS, in 1988. Microsoft wouldn t introduce a better filesystem for its consumer operating systems until Windows XP in 2001, 13 years later. But more on that story later.

Free Software, Shareware, and Commercial Software I ve covered the high cost of software already. Obviously $500 software wasn t going to sell in the home market. So what did we have? Mainly, these things:
  1. Public domain software. It was free to use, and if implemented in BASIC, probably had source code with it too.
  2. Shareware
  3. Commercial software (some of it from small publishers was a lot cheaper than $500)
Let s talk about shareware. The idea with shareware was that a company would release a useful program, sometimes limited. You were encouraged to register , or pay for, it if you liked it and used it. And, regardless of whether you registered it or not, were told please copy! Sometimes shareware was fully functional, and registering it got you nothing more than printed manuals and an easy conscience (guilt trips for not registering weren t necessarily very subtle). Sometimes unregistered shareware would have a nag screen a delay of a few seconds while they told you to register. Sometimes they d be limited in some way; you d get more features if you registered. With games, it was popular to have a trilogy, and release the first episode inevitably ending with a cliffhanger as shareware, and the subsequent episodes would require registration. In any event, a lot of software people used in the 80s and 90s was shareware. Also pirated commercial software, though in the earlier days of computing, I think some people didn t even know the difference. Notice what s missing: Free Software / FLOSS in the Richard Stallman sense of the word. Stallman lived in the big institution world after all, he worked at MIT and what he was doing with the Free Software Foundation and GNU project beginning in 1983 never really filtered into the DOS/Windows world at the time. I had no awareness of it even existing until into the 90s, when I first started getting some hints of it as a port of gcc became available for OS/2. The Internet was what really brought this home, but I m getting ahead of myself. I want to say again: FLOSS never really entered the DOS and Windows 3.x ecosystems. You d see it make a few inroads here and there in later versions of Windows, and moreso now that Microsoft has been sort of forced to accept it, but still, reflect on its legacy. What is the software market like in Windows compared to Linux, even today? Now it is, finally, time to talk about connectivity!

Getting On-Line What does it even mean to get on line? Certainly not connecting to a wifi access point. The answer is, unsurprisingly, complex. But for everyone except the large institutional users, it begins with a telephone.

The telephone system By the 80s, there was one communication network that already reached into nearly every home in America: the phone system. Virtually every household (note I don t say every person) was uniquely identified by a 10-digit phone number. You could, at least in theory, call up virtually any other phone in the country and be connected in less than a minute. But I ve got to talk about cost. The way things worked in the USA, you paid a monthly fee for a phone line. Included in that monthly fee was unlimited local calling. What is a local call? That was an extremely complex question. Generally it meant, roughly, calling within your city. But of course, as you deal with things like suburbs and cities growing into each other (eg, the Dallas-Ft. Worth metroplex), things got complicated fast. But let s just say for simplicity you could call others in your city. What about calling people not in your city? That was long distance , and you paid often hugely by the minute for it. Long distance rates were difficult to figure out, but were generally most expensive during business hours and cheapest at night or on weekends. Prices eventually started to come down when competition was introduced for long distance carriers, but even then you often were stuck with a single carrier for long distance calls outside your city but within your state. Anyhow, let s just leave it at this: local calls were virtually free, and long distance calls were extremely expensive.

Getting a modem I remember getting a modem that ran at either 1200bps or 2400bps. Either way, quite slow; you could often read even plain text faster than the modem could display it. But what was a modem? A modem hooked up to a computer with a serial cable, and to the phone system. By the time I got one, modems could automatically dial and answer. You would send a command like ATDT5551212 and it would dial 555-1212. Modems had speakers, because often things wouldn t work right, and the telephone system was oriented around speech, so you could hear what was happening. You d hear it wait for dial tone, then dial, then hopefully the remote end would ring, a modem there would answer, you d hear the screeching of a handshake, and eventually your terminal would say CONNECT 2400. Now your computer was bridged to the other; anything going out your serial port was encoded as sound by your modem and decoded at the other end, and vice-versa. But what, exactly, was the other end? It might have been another person at their computer. Turn on local echo, and you can see what they did. Maybe you d send files to each other. But in my case, the answer was different: PC Magazine.

PC Magazine and CompuServe Starting around 1986 (so I would have been about 6 years old), I got to read PC Magazine. My dad would bring copies that were being discarded at his office home for me to read, and I think eventually bought me a subscription directly. This was not just a standard magazine; it ran something like 350-400 pages an issue, and came out every other week. This thing was a monster. It had reviews of hardware and software, descriptions of upcoming technologies, pages and pages of ads (that often had some degree of being informative to them). And they had sections on programming. Many issues would talk about BASIC or Pascal programming, and there d be a utility in most issues. What do I mean by a utility in most issues ? Did they include a floppy disk with software? No, of course not. There was a literal program listing printed in the magazine. If you wanted the utility, you had to type it in. And a lot of them were written in assembler, so you had to have an assembler. An assembler, of course, was not free and I didn t have one. Or maybe they wrote it in Microsoft C, and I had Borland C, and (of course) they weren t compatible. Sometimes they would list the program sort of in binary: line after line of a BASIC program, with lines like 64, 193, 253, 0, 53, 0, 87 that you would type in for hours, hopefully correctly. Running the BASIC program would, if you got it correct, emit a .COM file that you could then run. They did have a rudimentary checksum system built in, but it wasn t even a CRC, so something like swapping two numbers you d never notice except when the program would mysteriously hang. Eventually they teamed up with CompuServe to offer a limited slice of CompuServe for the purpose of downloading PC Magazine utilities. This was called PC MagNet. I am foggy on the details, but I believe that for a time you could connect to the limited PC MagNet part of CompuServe for free (after the cost of the long-distance call, that is) rather than paying for CompuServe itself (because, OF COURSE, that also charged you per the minute.) So in the early days, I would get special permission from my parents to place a long distance call, and after some nerve-wracking minutes in which we were aware every minute was racking up charges, I could navigate the menus, download what I wanted, and log off immediately. I still, incidentally, mourn what PC Magazine became. As with computing generally, it followed the mass market. It lost its deep technical chops, cut its programming columns, stopped talking about things like how SCSI worked, and so forth. By the time it stopped printing in 2009, it was no longer a square-bound 400-page beheamoth, but rather looked more like a copy of Newsweek, but with less depth.

Continuing with CompuServe CompuServe was a much larger service than just PC MagNet. Eventually, our family got a subscription. It was still an expensive and scarce resource; I d call it only after hours when the long-distance rates were cheapest. Everyone had a numerical username separated by commas; mine was 71510,1421. CompuServe had forums, and files. Eventually I would use TapCIS to queue up things I wanted to do offline, to minimize phone usage online. CompuServe eventually added a gateway to the Internet. For the sum of somewhere around $1 a message, you could send or receive an email from someone with an Internet email address! I remember the thrill of one time, as a kid of probably 11 years, sending a message to one of the editors of PC Magazine and getting a kind, if brief, reply back! But inevitably I had

The Godzilla Phone Bill Yes, one month I became lax in tracking my time online. I ran up my parents phone bill. I don t remember how high, but I remember it was hundreds of dollars, a hefty sum at the time. As I watched Jason Scott s BBS Documentary, I realized how common an experience this was. I think this was the end of CompuServe for me for awhile.

Toll-Free Numbers I lived near a town with a population of 500. Not even IN town, but near town. The calling area included another town with a population of maybe 1500, so all told, there were maybe 2000 people total I could talk to with a local call though far fewer numbers, because remember, telephones were allocated by the household. There was, as far as I know, zero modems that were a local call (aside from one that belonged to a friend I met in around 1992). So basically everything was long-distance. But there was a special feature of the telephone network: toll-free numbers. Normally when calling long-distance, you, the caller, paid the bill. But with a toll-free number, beginning with 1-800, the recipient paid the bill. These numbers almost inevitably belonged to corporations that wanted to make it easy for people to call. Sales and ordering lines, for instance. Some of these companies started to set up modems on toll-free numbers. There were few of these, but they existed, so of course I had to try them! One of them was a company called PennyWise that sold office supplies. They had a toll-free line you could call with a modem to order stuff. Yes, online ordering before the web! I loved office supplies. And, because I lived far from a big city, if the local K-Mart didn t have it, I probably couldn t get it. Of course, the interface was entirely text, but you could search for products and place orders with the modem. I had loads of fun exploring the system, and actually ordered things from them and probably actually saved money doing so. With the first order they shipped a monster full-color catalog. That thing must have been 500 pages, like the Sears catalogs of the day. Every item had a part number, which streamlined ordering through the modem.

Inbound FAXes By the 90s, a number of modems became able to send and receive FAXes as well. For those that don t know, a FAX machine was essentially a special modem. It would scan a page and digitally transmit it over the phone system, where it would at least in the early days be printed out in real time (because the machines didn t have the memory to store an entire page as an image). Eventually, PC modems integrated FAX capabilities. There still wasn t anything useful I could do locally, but there were ways I could get other companies to FAX something to me. I remember two of them. One was for US Robotics. They had an on demand FAX system. You d call up a toll-free number, which was an automated IVR system. You could navigate through it and select various documents of interest to you: spec sheets and the like. You d key in your FAX number, hang up, and US Robotics would call YOU and FAX you the documents you wanted. Yes! I was talking to a computer (of a sorts) at no cost to me! The New York Times also ran a service for awhile called TimesFax. Every day, they would FAX out a page or two of summaries of the day s top stories. This was pretty cool in an era in which I had no other way to access anything from the New York Times. I managed to sign up for TimesFax I have no idea how, anymore and for awhile I would get a daily FAX of their top stories. When my family got its first laser printer, I could them even print these FAXes complete with the gothic New York Times masthead. Wow! (OK, so technically I could print it on a dot-matrix printer also, but graphics on a 9-pin dot matrix is a kind of pain that is a whole other article.)

My own phone line Remember how I discussed that phone lines were allocated per household? This was a problem for a lot of reasons:
  1. Anybody that tried to call my family while I was using my modem would get a busy signal (unable to complete the call)
  2. If anybody in the house picked up the phone while I was using it, that would degrade the quality of the ongoing call and either mess up or disconnect the call in progress. In many cases, that could cancel a file transfer (which wasn t necessarily easy or possible to resume), prompting howls of annoyance from me.
  3. Generally we all had to work around each other
So eventually I found various small jobs and used the money I made to pay for my own phone line and my own long distance costs. Eventually I upgraded to a 28.8Kbps US Robotics Courier modem even! Yes, you heard it right: I got a job and a bank account so I could have a phone line and a faster modem. Uh, isn t that why every teenager gets a job? Now my local friend and I could call each other freely at least on my end (I can t remember if he had his own phone line too). We could exchange files using HS/Link, which had the added benefit of allowing split-screen chat even while a file transfer is in progress. I m sure we spent hours chatting to each other keyboard-to-keyboard while sharing files with each other.

Technology in Schools By this point in the story, we re in the late 80s and early 90s. I m still using PC-style OSs at home; OS/2 in the later years of this period, DOS or maybe a bit of Windows in the earlier years. I mentioned that they let me work on programming at school starting in 5th grade. It was soon apparent that I knew more about computers than anybody on staff, and I started getting pulled out of class to help teachers or administrators with vexing school problems. This continued until I graduated from high school, incidentally often to my enjoyment, and the annoyance of one particular teacher who, I must say, I was fine with annoying in this way. That s not to say that there was institutional support for what I was doing. It was, after all, a small school. Larger schools might have introduced BASIC or maybe Logo in high school. But I had already taught myself BASIC, Pascal, and C by the time I was somewhere around 12 years old. So I wouldn t have had any use for that anyhow. There were programming contests occasionally held in the area. Schools would send teams. My school didn t really send anybody, but I went as an individual. One of them was run by a local college (but for jr. high or high school students. Years later, I met one of the professors that ran it. He remembered me, and that day, better than I did. The programming contest had problems one could solve in BASIC or Logo. I knew nothing about what to expect going into it, but I had lugged my computer and screen along, and asked him, Can I write my solutions in C? He was, apparently, stunned, but said sure, go for it. I took first place that day, leading to some rather confused teams from much larger schools. The Netware network that the school had was, as these generally were, itself isolated. There was no link to the Internet or anything like it. Several schools across three local counties eventually invested in a fiber-optic network linking them together. This built a larger, but still closed, network. Its primary purpose was to allow students to be exposed to a wider variety of classes at high schools. Participating schools had an ITV room , outfitted with cameras and mics. So students at any school could take classes offered over ITV at other schools. For instance, only my school taught German classes, so people at any of those participating schools could take German. It was an early Zoom room. But alongside the TV signal, there was enough bandwidth to run some Netware frames. By about 1995 or so, this let one of the schools purchase some CD-ROM software that was made available on a file server and could be accessed by any participating school. Nice! But Netware was mainly about file and printer sharing; there wasn t even a facility like email, at least not on our deployment.

BBSs My last hop before the Internet was the BBS. A BBS was a computer program, usually ran by a hobbyist like me, on a computer with a modem connected. Callers would call it up, and they d interact with the BBS. Most BBSs had discussion groups like forums and file areas. Some also had games. I, of course, continued to have that most vexing of problems: they were all long-distance. There were some ways to help with that, chiefly QWK and BlueWave. These, somewhat like TapCIS in the CompuServe days, let me download new message posts for reading offline, and queue up my own messages to send later. QWK and BlueWave didn t help with file downloading, though.

BBSs get networked BBSs were an interesting thing. You d call up one, and inevitably somewhere in the file area would be a BBS list. Download the BBS list and you ve suddenly got a list of phone numbers to try calling. All of them were long distance, of course. You d try calling them at random and have a success rate of maybe 20%. The other 80% would be defunct; you might get the dreaded this number is no longer in service or the even more dreaded angry human answering the phone (and of course a modem can t talk to a human, so they d just get silence for probably the nth time that week). The phone company cared nothing about BBSs and recycled their numbers just as fast as any others. To talk to various people, or participate in certain discussion groups, you d have to call specific BBSs. That s annoying enough in the general case, but even more so for someone paying long distance for it all, because it takes a few minutes to establish a connection to a BBS: handshaking, logging in, menu navigation, etc. But BBSs started talking to each other. The earliest successful such effort was FidoNet, and for the duration of the BBS era, it remained by far the largest. FidoNet was analogous to the UUCP that the institutional users had, but ran on the much cheaper PC hardware. Basically, BBSs that participated in FidoNet would relay email, forum posts, and files between themselves overnight. Eventually, as with UUCP, by hopping through this network, messages could reach around the globe, and forums could have worldwide participation asynchronously, long before they could link to each other directly via the Internet. It was almost entirely volunteer-run.

Running my own BBS At age 13, I eventually chose to set up my own BBS. It ran on my single phone line, so of course when I was dialing up something else, nobody could dial up me. Not that this was a huge problem; in my town of 500, I probably had a good 1 or 2 regular callers in the beginning. In the PC era, there was a big difference between a server and a client. Server-class software was expensive and rare. Maybe in later years you had an email client, but an email server would be completely unavailable to you as a home user. But with a BBS, I could effectively run a server. I even ran serial lines in our house so that the BBS could be connected from other rooms! Since I was running OS/2, the BBS didn t tie up the computer; I could continue using it for other things. FidoNet had an Internet email gateway. This one, unlike CompuServe s, was free. Once I had a BBS on FidoNet, you could reach me from the Internet using the FidoNet address. This didn t support attachments, but then email of the day didn t really, either. Various others outside Kansas ran FidoNet distribution points. I believe one of them was mgmtsys; my memory is quite vague, but I think they offered a direct gateway and I would call them to pick up Internet mail via FidoNet protocols, but I m not at all certain of this.

Pros and Cons of the Non-Microsoft World As mentioned, Microsoft was and is the dominant operating system vendor for PCs. But I left that world in 1993, and here, nearly 30 years later, have never really returned. I got an operating system with more technical capabilities than the DOS and Windows of the day, but the tradeoff was a much smaller software ecosystem. OS/2 could run DOS programs, but it ran OS/2 programs a lot better. So if I were to run a BBS, I wanted one that had a native OS/2 version limiting me to a small fraction of available BBS server software. On the other hand, as a fully 32-bit operating system, there started to be OS/2 ports of certain software with a Unix heritage; most notably for me at the time, gcc. At some point, I eventually came across the RMS essays and started to be hooked.

Internet: The Hunt Begins I certainly was aware that the Internet was out there and interesting. But the first problem was: how the heck do I get connected to the Internet?

Computer labs There was one place that tended to have Internet access: colleges and universities. In 7th grade, I participated in a program that resulted in me being invited to visit Duke University, and in 8th grade, I participated in National History Day, resulting in a trip to visit the University of Maryland. I probably sought out computer labs at both of those. My most distinct memory was finding my way into a computer lab at one of those universities, and it was full of NeXT workstations. I had never seen or used NeXT before, and had no idea how to operate it. I had brought a box of floppy disks, unaware that the DOS disks probably weren t compatible with NeXT. Closer to home, a small college had a computer lab that I could also visit. I would go there in summer or when it wasn t used with my stack of floppies. I remember downloading disk images of FLOSS operating systems: FreeBSD, Slackware, or Debian, at the time. The hash marks from the DOS-based FTP client would creep across the screen as the 1.44MB disk images would slowly download. telnet was also available on those machines, so I could telnet to things like public-access Archie servers and libraries though not Gopher. Still, FTP and telnet access opened up a lot, and I learned quite a bit in those years.

Continuing the Journey At some point, I got a copy of the Whole Internet User s Guide and Catalog, published in 1994. I still have it. If it hadn t already figured it out by then, I certainly became aware from it that Unix was the dominant operating system on the Internet. The examples in Whole Internet covered FTP, telnet, gopher all assuming the user somehow got to a Unix prompt. The web was introduced about 300 pages in; clearly viewed as something that wasn t page 1 material. And it covered the command-line www client before introducing the graphical Mosaic. Even then, though, the book highlighted Mosaic s utility as a front-end for Gopher and FTP, and even the ability to launch telnet sessions by clicking on links. But having a copy of the book didn t equate to having any way to run Mosaic. The machines in the computer lab I mentioned above all ran DOS and were incapable of running a graphical browser. I had no SLIP or PPP (both ways to run Internet traffic over a modem) connectivity at home. In short, the Web was something for the large institutional users at the time.

CD-ROMs As CD-ROMs came out, with their huge (for the day) 650MB capacity, various companies started collecting software that could be downloaded on the Internet and selling it on CD-ROM. The two most popular ones were Walnut Creek CD-ROM and Infomagic. One could buy extensive Shareware and gaming collections, and then even entire Linux and BSD distributions. Although not exactly an Internet service per se, it was a way of bringing what may ordinarily only be accessible to institutional users into the home computer realm.

Free Software Jumps In As I mentioned, by the mid 90s, I had come across RMS s writings about free software most probably his 1992 essay Why Software Should Be Free. (Please note, this is not a commentary on the more recently-revealed issues surrounding RMS, but rather his writings and work as I encountered them in the 90s.) The notion of a Free operating system not just in cost but in openness was incredibly appealing. Not only could I tinker with it to a much greater extent due to having source for everything, but it included so much software that I d otherwise have to pay for. Compilers! Interpreters! Editors! Terminal emulators! And, especially, server software of all sorts. There d be no way I could afford or run Netware, but with a Free Unixy operating system, I could do all that. My interest was obviously piqued. Add to that the fact that I could actually participate and contribute I was about to become hooked on something that I ve stayed hooked on for decades. But then the question was: which Free operating system? Eventually I chose FreeBSD to begin with; that would have been sometime in 1995. I don t recall the exact reasons for that. I remember downloading Slackware install floppies, and probably the fact that Debian wasn t yet at 1.0 scared me off for a time. FreeBSD s fantastic Handbook far better than anything I could find for Linux at the time was no doubt also a factor.

The de Raadt Factor Why not NetBSD or OpenBSD? The short answer is Theo de Raadt. Somewhere in this time, when I was somewhere between 14 and 16 years old, I asked some questions comparing NetBSD to the other two free BSDs. This was on a NetBSD mailing list, but for some reason Theo saw it and got a flame war going, which CC d me. Now keep in mind that even if NetBSD had a web presence at the time, it would have been minimal, and I would have not all that unusually for the time had no way to access it. I was certainly not aware of the, shall we say, acrimony between Theo and NetBSD. While I had certainly seen an online flamewar before, this took on a different and more disturbing tone; months later, Theo randomly emailed me under the subject SLIME saying that I was, well, SLIME . I seem to recall periodic emails from him thereafter reminding me that he hates me and that he had blocked me. (Disclaimer: I have poor email archives from this period, so the full details are lost to me, but I believe I am accurately conveying these events from over 25 years ago) This was a surprise, and an unpleasant one. I was trying to learn, and while it is possible I didn t understand some aspect or other of netiquette (or Theo s personal hatred of NetBSD) at the time, still that is not a reason to flame a 16-year-old (though he would have had no way to know my age). This didn t leave any kind of scar, but did leave a lasting impression; to this day, I am particularly concerned with how FLOSS projects handle poisonous people. Debian, for instance, has come a long way in this over the years, and even Linus Torvalds has turned over a new leaf. I don t know if Theo has. In any case, I didn t use NetBSD then. I did try it periodically in the years since, but never found it compelling enough to justify a large switch from Debian. I never tried OpenBSD for various reasons, but one of them was that I didn t want to join a community that tolerates behavior such as Theo s from its leader.

Moving to FreeBSD Moving from OS/2 to FreeBSD was final. That is, I didn t have enough hard drive space to keep both. I also didn t have the backup capacity to back up OS/2 completely. My BBS, which ran Virtual BBS (and at some point also AdeptXBBS) was deleted and reincarnated in a different form. My BBS was a member of both FidoNet and VirtualNet; the latter was specific to VBBS, and had to be dropped. I believe I may have also had to drop the FidoNet link for a time. This was the biggest change of computing in my life to that point. The earlier experiences hadn t literally destroyed what came before. OS/2 could still run my DOS programs. Its command shell was quite DOS-like. It ran Windows programs. I was going to throw all that away and leap into the unknown. I wish I had saved a copy of my BBS; I would love to see the messages I exchanged back then, or see its menu screens again. I have little memory of what it looked like. But other than that, I have no regrets. Pursuing Free, Unixy operating systems brought me a lot of enjoyment and a good career. That s not to say it was easy. All the problems of not being in the Microsoft ecosystem were magnified under FreeBSD and Linux. In a day before EDID, monitor timings had to be calculated manually and you risked destroying your monitor if you got them wrong. Word processing and spreadsheet software was pretty much not there for FreeBSD or Linux at the time; I was therefore forced to learn LaTeX and actually appreciated that. Software like PageMaker or CorelDraw was certainly nowhere to be found for those free operating systems either. But I got a ton of new capabilities. I mentioned the BBS didn t shut down, and indeed it didn t. I ran what was surely a supremely unique oddity: a free, dialin Unix shell server in the middle of a small town in Kansas. I m sure I provided things such as pine for email and some help text and maybe even printouts for how to use it. The set of callers slowly grew over the time period, in fact. And then I got UUCP.

Enter UUCP Even throughout all this, there was no local Internet provider and things were still long distance. I had Internet Email access via assorted strange routes, but they were all strange. And, I wanted access to Usenet. In 1995, it happened. The local ISP I mentioned offered UUCP access. Though I couldn t afford the dialup shell (or later, SLIP/PPP) that they offered due to long-distance costs, UUCP s very efficient batched processes looked doable. I believe I established that link when I was 15, so in 1995. I worked to register my domain, complete.org, as well. At the time, the process was a bit lengthy and involved downloading a text file form, filling it out in a precise way, sending it to InterNIC, and probably mailing them a check. Well I did that, and in September of 1995, complete.org became mine. I set up sendmail on my local system, as well as INN to handle the limited Usenet newsfeed I requested from the ISP. I even ran Majordomo to host some mailing lists, including some that were surprisingly high-traffic for a few-times-a-day long-distance modem UUCP link! The modem client programs for FreeBSD were somewhat less advanced than for OS/2, but I believe I wound up using Minicom or Seyon to continue to dial out to BBSs and, I believe, continue to use Learning Link. So all the while I was setting up my local BBS, I continued to have access to the text Internet, consisting of chiefly Gopher for me.

Switching to Debian I switched to Debian sometime in 1995 or 1996, and have been using Debian as my primary OS ever since. I continued to offer shell access, but added the WorldVU Atlantis menuing BBS system. This provided a return of a more BBS-like interface (by default; shell was still an uption) as well as some BBS door games such as LoRD and TradeWars 2002, running under DOS emulation. I also continued to run INN, and ran ifgate to allow FidoNet echomail to be presented into INN Usenet-like newsgroups, and netmail to be gated to Unix email. This worked pretty well. The BBS continued to grow in these days, peaking at about two dozen total user accounts, and maybe a dozen regular users.

Dial-up access availability I believe it was in 1996 that dial up PPP access finally became available in my small town. What a thrill! FINALLY! I could now FTP, use Gopher, telnet, and the web all from home. Of course, it was at modem speeds, but still. (Strangely, I have a memory of accessing the Web using WebExplorer from OS/2. I don t know exactly why; it s possible that by this time, I had upgraded to a 486 DX2/66 and was able to reinstall OS/2 on the old 25MHz 486, or maybe something was wrong with the timeline from my memories from 25 years ago above. Or perhaps I made the occasional long-distance call somewhere before I ditched OS/2.) Gopher sites still existed at this point, and I could access them using Netscape Navigator which likely became my standard Gopher client at that point. I don t recall using UMN text-mode gopher client locally at that time, though it s certainly possible I did.

The city Starting when I was 15, I took computer science classes at Wichita State University. The first one was a class in the summer of 1995 on C++. I remember being worried about being good enough for it I was, after all, just after my HS freshman year and had never taken the prerequisite C class. I loved it and got an A! By 1996, I was taking more classes. In 1996 or 1997 I stayed in Wichita during the day due to having more than one class. So, what would I do then but enjoy the computer lab? The CS dept. had two of them: one that had NCD X terminals connected to a pair of SunOS servers, and another one running Windows. I spent most of the time in the Unix lab with the NCDs; I d use Netscape or pine, write code, enjoy the University s fast Internet connection, and so forth. In 1997 I had graduated high school and that summer I moved to Wichita to attend college. As was so often the case, I shut down the BBS at that time. It would be 5 years until I again dealt with Internet at home in a rural community. By the time I moved to my apartment in Wichita, I had stopped using OS/2 entirely. I have no memory of ever having OS/2 there. Along the way, I had bought a Pentium 166, and then the most expensive piece of computing equipment I have ever owned: a DEC Alpha, which, of course, ran Linux.

ISDN I must have used dialup PPP for a time, but I eventually got a job working for the ISP I had used for UUCP, and then PPP. While there, I got a 128Kbps ISDN line installed in my apartment, and they gave me a discount on the service for it. That was around 3x the speed of a modem, and crucially was always on and gave me a public IP. No longer did I have to use UUCP; now I got to host my own things! By at least 1998, I was running a web server on www.complete.org, and I had an FTP server going as well.

Even Bigger Cities In 1999 I moved to Dallas, and there got my first broadband connection: an ADSL link at, I think, 1.5Mbps! Now that was something! But it had some reliability problems. I eventually put together a server and had it hosted at an acquantaince s place who had SDSL in his apartment. Within a couple of years, I had switched to various kinds of proper hosting for it, but that is a whole other article. In Indianapolis, I got a cable modem for the first time, with even tighter speeds but prohibitions on running servers on it. Yuck.

Challenges Being non-Microsoft continued to have challenges. Until the advent of Firefox, a web browser was one of the biggest. While Netscape supported Linux on i386, it didn t support Linux on Alpha. I hobbled along with various attempts at emulators, old versions of Mosaic, and so forth. And, until StarOffice was open-sourced as Open Office, reading Microsoft file formats was also a challenge, though WordPerfect was briefly available for Linux. Over the years, I have become used to the Linux ecosystem. Perhaps I use Gimp instead of Photoshop and digikam instead of well, whatever somebody would use on Windows. But I get ZFS, and containers, and so much that isn t available there. Yes, I know Apple never went away and is a thing, but for most of the time period I discuss in this article, at least after the rise of DOS, it was niche compared to the PC market.

Back to Kansas In 2002, I moved back to Kansas, to a rural home near a different small town in the county next to where I grew up. Over there, it was back to dialup at home, but I had faster access at work. I didn t much care for this, and thus began a 20+-year effort to get broadband in the country. At first, I got a wireless link, which worked well enough in the winter, but had serious problems in the summer when the trees leafed out. Eventually DSL became available locally highly unreliable, but still, it was something. Then I moved back to the community I grew up in, a few miles from where I grew up. Again I got DSL a bit better. But after some years, being at the end of the run of DSL meant I had poor speeds and reliability problems. I eventually switched to various wireless ISPs, which continues to the present day; while people in cities can get Gbps service, I can get, at best, about 50Mbps. Long-distance fees are gone, but the speed disparity remains.

Concluding Reflections I am glad I grew up where I did; the strong community has a lot of advantages I don t have room to discuss here. In a number of very real senses, having no local services made things a lot more difficult than they otherwise would have been. However, perhaps I could say that I also learned a lot through the need to come up with inventive solutions to those challenges. To this day, I think a lot about computing in remote environments: partially because I live in one, and partially because I enjoy visiting places that are remote enough that they have no Internet, phone, or cell service whatsoever. I have written articles like Tools for Communicating Offline and in Difficult Circumstances based on my own personal experience. I instinctively think about making protocols robust in the face of various kinds of connectivity failures because I experience various kinds of connectivity failures myself.

(Almost) Everything Lives On In 2002, Gopher turned 10 years old. It had probably been about 9 or 10 years since I had first used Gopher, which was the first way I got on live Internet from my house. It was hard to believe. By that point, I had an always-on Internet link at home and at work. I had my Alpha, and probably also at least PCMCIA Ethernet for a laptop (many laptops had modems by the 90s also). Despite its popularity in the early 90s, less than 10 years after it came on the scene and started to unify the Internet, it was mostly forgotten. And it was at that moment that I decided to try to resurrect it. The University of Minnesota finally released it under an Open Source license. I wrote the first new gopher server in years, pygopherd, and introduced gopher to Debian. Gopher lives on; there are now quite a few Gopher clients and servers out there, newly started post-2002. The Gemini protocol can be thought of as something akin to Gopher 2.0, and it too has a small but blossoming ecosystem. Archie, the old FTP search tool, is dead though. Same for WAIS and a number of the other pre-web search tools. But still, even FTP lives on today. And BBSs? Well, they didn t go away either. Jason Scott s fabulous BBS documentary looks back at the history of the BBS, while Back to the BBS from last year talks about the modern BBS scene. FidoNet somehow is still alive and kicking. UUCP still has its place and has inspired a whole string of successors. Some, like NNCP, are clearly direct descendents of UUCP. Filespooler lives in that ecosystem, and you can even see UUCP concepts in projects as far afield as Syncthing and Meshtastic. Usenet still exists, and you can now run Usenet over NNCP just as I ran Usenet over UUCP back in the day (which you can still do as well). Telnet, of course, has been largely supplanted by ssh, but the concept is more popular now than ever, as Linux has made ssh be available on everything from Raspberry Pi to Android. And I still run a Gopher server, looking pretty much like it did in 2002. This post also has a permanent home on my website, where it may be periodically updated.

23 August 2022

Ian Jackson: prefork-interp - automatic startup time amortisation for all manner of scripts

The problem I had - Mason, so, sadly, FastCGI Since the update to current Debian stable, the website for YARRG, (a play-aid for Puzzle Pirates which I wrote some years ago), started to occasionally return Internal Server Error , apparently due to bug(s) in some FastCGI libraries. I was using FastCGI because the website is written in Mason, a Perl web framework, and I found that Mason CGI calls were slow. I m using CGI - yes, trad CGI - via userv-cgi. Running Mason this way would compile the template for each HTTP request just when it was rendered, and then throw the compiled version away. The more modern approach of an application server doesn t scale well to a system which has many web applications most of which are very small. The admin overhead of maintaining a daemon, and corresponding webserver config, for each such service would be prohibitive, even with some kind of autoprovisioning setup. FastCGI has an interpreter wrapper which seemed like it ought to solve this problem, but it s quite inconvenient, and often flaky. I decided I could do better, and set out to eliminate FastCGI from my setup. The result seems to be a success; once I d done all the hard work of writing prefork-interp, I found the result very straightforward to deploy. prefork-interp prefork-interp is a small C program which wraps a script, plus a scripting language library to cooperate with the wrapper program. Together they achieve the following:
  • Startup cost of the script (loading modules it uses, precompuations, loading and processing of data files, etc.) is paid once, and reused for subsequent invocations of the same script.
  • Minimal intervention to the script source code:
    • one new library to import
    • one new call to make from that library, right after the script intialisation is complete
    • change to the #! line.
  • The new initialisation complete call turns the program into a little server (a daemon), and then returns once for each actual invocation, each time in a fresh grandchild process.
Features:
  • Seamless reloading on changes to the script source code (automatic, and configurable).
  • Concurrency limiting.
  • Options for distinguishing different configurations of the same script so that they get a server each.
  • You can run the same script standalone, as a one-off execution, as well as under prefork-interp.
  • Currently, a script-side library is provided for Perl. I m pretty sure Python would be fairly straightforward.
Important properties not always satisfied by competing approaches:
  • Error output (stderr) and exit status from both phases of the script code execution faithfully reproduced to the calling context. Environment, arguments, and stdin/stdout/stderr descriptors, passed through to each invocation.
  • No polling, other than a long-term idle timeout, so good on laptops (or phones).
  • Automatic lifetime management of the per-script server, including startup and cleanup. No integration needed with system startup machinery: No explicit management of daemons, init scripts, systemd units, cron jobs, etc.
  • Useable right away without fuss for CGI programs but also for other kinds of program invocation.
  • (I believe) reliable handling of unusual states arising from failed invocations or races.
Swans paddling furiously The implementation is much more complicated than the (apparent) interface. I won t go into all the details here (there are some terrifying diagrams in the source code if you really want), but some highlights: We use an AF_UNIX socket (hopefully in /run/user/UID, but in ~ if not) for rendezvous. We can try to connect without locking, but we must protect the socket with a separate lockfile to avoid two concurrent restart attempts. We want stderr from the script setup (pre-initialisation) to be delivered to the caller, so the script ought to inherit our stderr and then will need to replace it later. Twice, in fact, because the daemonic server process can t have a stderr. When a script is restarted for any reason, any old socket will be removed. We want the old server process to detect that and quit. (If hung about, it would wait for the idle timeout; if this happened a lot - eg, a constantly changing set of services - we might end up running out of pids or something.) Spotting the socket disappearing, without polling, involves use of a library capable of using inotify (or the equivalent elsewhere). Choosing a C library to do this is not so hard, but portable interfaces to this functionality can be hard to find in scripting languages, and also we don t want every language binding to have to reimplement these checks. So for this purpose there s a little watcher process, and associated IPC. When an invoking instance of prefork-interp is killed, we must arrange for the executing service instance to stop reading from its stdin (and, ideally, writing its stdout). Otherwise it s stealing input from prefork-interp s successors (maybe the user s shell)! Cleanup ought not to depend on positive actions by failing processes, so each element of the system has to detect failures of its peers by means such as EOF on sockets/pipes. Obtaining prefork-interp I put this new tool in my chiark-utils package, which is a collection of useful miscellany. It s available from git. Currently I make releases by uploading to Debian, where prefork-interp has just hit Debian unstable, in chiark-utils 7.0.0. Support for other scripting languages I would love Python to be supported. If any pythonistas reading this think you might like to help out, please get in touch. The specification for the protocol, and what the script library needs to do, is documented in the source code Future plans for chiark-utils chiark-utils as a whole is in need of some tidying up of its build system and packaging. I intend to try to do some reorganisation. Currently I think it would be better to organising the source tree more strictly with a directory for each included facility, rather than grouping compiled and scripts together. The Debian binary packages should be reorganised more fully according to their dependencies, so that installing a program will ensure that it works. I should probably move the official git repo from my own git+gitweb to a forge (so we can have MRs and issues and so on). And there should be a lot more testing, including Debian autopkgtests.
edited 2022-08-23 10:30 +01:00 to improve the formatting


comment count unavailable comments

29 July 2022

Bits from Debian: New Debian Developers and Maintainers (May and June 2022)

The following contributors got their Debian Developer accounts in the last two months:
  • Geoffroy Berret (kaliko)
  • Arnaud Ferraris (aferraris)
The following contributors were added as Debian Maintainers in the last two months:
  • Alec Leanas
  • Christopher Michael Obbard
  • Lance Lin
  • Stefan Kropp
  • Matteo Bini
  • Tino Didriksen
Congratulations!

20 July 2022

Enrico Zini: Deconstruction of the DAM hat

Further reading Talk notes Intro
  • I'm not speaking for the whole of DAM
  • Motivation in part is personal frustration, and need to set boundaries and negotiate expectations
Debian Account Managers
  • history
Responsibility for official membership
  • approve account creation
  • manage the New Member Process and nm.debian.org
  • close MIA accounts
  • occasional emergency termination of accounts
  • handle Emeritus
  • with lots of help from FrontDesk and MIA teams (big shoutout)
What DAM is not
  • we are not mediators
  • we are not a community management team
  • a list or IRC moderation team
  • we are not responsible for vision or strategic choices about how people are expected to interact in Debian
  • We shouldn't try and solve things because they need solving
Unexpected responsibilities
  • Over time, the community has grown larger and more complex, in a larger and more complex online environment
  • Enforcing the Diversity Statement and the Code of Conduct
  • Emergency list moderation
    • we have ended up using DAM warnings to compensate for the lack of list moderation, at least twice
  • contributors.debian.org (mostly only because of me, but it would be good to have its own team)
DAM warnings
  • except for rare glaring cases, patterns of behaviour / intentions / taking feedback in, are more relevant than individual incidents
  • we do not set out to fix people. It is enough for us to get people to acknowledge a problem
    • if they can't acknowledge a problem they're probably out
    • once a problem is acknowledged, fixing it could be their implementation detail
    • then again it's not that easy to get a number of troublesome people to acknowledge problems, so we go back to the problem of deciding when enough is enough
DAM warnings?
  • I got to a point where I look at DAM warnings as potential signals that DAM has ended up with the ball that everyone else in Debian dropped.
  • DAM warning means we haven't gotten to a last resort situation yet, meaning that it probably shouldn't be DAM dealing with this at this point
  • Everyone in the project can write a person "do you realise there's an issue here? Can you do something to stop?", and give them a chance to reflect on issues or ignore them, and build their reputation accordingly.
  • People in Debian should not have to endure, completey powerless, as trolls drag painful list discussions indefinitely until all the trolled people run out of energy and leave. At the same time, people who abuse a list should expect to be suspended or banned from the list, not have their Debian membership put into question (unless it is a recurring pattern of behaviour).
  • The push to grow DAM warnings as a tool, is a sign of the rest of Debian passing on their responsibilities, and DAM picking them up.
  • Then in DAM we end up passing on things, too, because we also don't have the energy to face another intensive megametathread, and as we take actions for things that shouldn't quite be our responsibility, we face a higher level of controversy, and therefore demotivation.
  • Also, as we take actions for things that shouldn't be our responsibility, and work on a higher level of controversy, our legitimacy is undermined (and understandably so)
    • there's a pothole on my street that never gets filled, so at some point I go out and fill it. Then people thank me, people complain I shouldn't have, people complain I didn't fill it right, people appreciate the gesture and invite me to learn how to fix potholes better, people point me out to more potholes, and then complain that potholes don't get fixed properly on the whole street. I end up being the problem, instead of whoever had responsibility of the potholes but wasn't fixing them
  • The Community Team, the Diversity Team, and individual developers, have no energy or entitlement for explaining what a healthy community looks like, and DAM is left with that responsibility in the form of accountability for their actions: to issue, say, a DAM warning for bullying, we are expected to explain what is bullying, and how that kind of behaviour constitutes bullying, in a way that is understandable by the whole project.
  • Since there isn't consensus in the project about what bullying loos like, we end up having to define it in a warning, which again is a responsibility we shouldn't have, and we need to do it because we have an escalated situation at hand, but we can't do it right
House rules Interpreting house rules
  • you can't encode common sense about people behaviour in written rules: no matter how hard you try, people will find ways to cheat that
  • so one can use rules as a guideline, and someone responsible for the bits that can't go into rules.
    • context matters, privilege/oppression matters, patterns matter, histor matters
  • example:
    • call a person out for breaking a rule
    • get DARVO in response
    • state that DARVO is not acceptable
    • get concern trolling against margninalised people and accuse them of DARVO if they complain
  • example: assume good intentions vs enabling
  • example: rule lawyering and Figure skating
  • this cannot be solved by GRs: I/we (DAM)/possibly also we (Debian) don't want to do GRs about evaluating people
Governance by bullying
  • How to DoS discussions in Debian
    • example: gender, minority groups, affirmative action, inclusion, anything about the community team itself, anything about the CoC, systemd, usrmerge, dam warnings, expulsions
      • think of a topic. Think about sending a mail to debian-project about it. If you instinctively shiver at the thought, this is probably happening
      • would you send a mail about that to -project / -devel?
      • can you think of other topics?
    • it is an effective way of governance as it excludes topics from public discussion
  • A small number of people abuse all this, intentionally or not, to effectively manipulate decision making in the project.
  • Instead of using the rules of the community to bring forth the issues one cares about, it costs less energy to make it unthinkable or unbearable to have a discussion on issues one doesn't want to progress. What one can't stop constructively, one can oppose destructively.
  • even regularly diverting the discussion away from the original point or concern is enough to derail it without people realising you're doing it
  • This is an effective strategy for a few reckless people to unilaterally direct change, in the current state of Debian, at the cost of the health and the future of the community as a whole.
  • There are now a number of important issues nobody has the energy to discuss, because experience says that energy requirements to bring them to the foreground and deal with the consequences are anticipated to be disproportionate.
  • This is grave, as we're talking about trolling and bullying as malicious power moves to work around the accepted decision making structures of our community.
  • Solving this is out of scope for this talk, but it is urgent nevertheless, and can't be solved by expecting DAM to fix it
How about the Community Team?
  • It is also a small group of people who cannot pick up the responsibility of doing what the community isn't doing for itself
  • I believe we need to recover the Community Team: it's been years that every time they write something in public, they get bullied by the same recurring small group of people (see governance by bullying above)
How about DAM?
  • I was just saying that we are not the emergency catch all
  • When the only enforcement you have is "nuclear escalation", there's nothing you can do until it's too late, and meanwhile lots of people suffer (this was written before Russia invaded Ukraine)
  • Also, when issues happen on public lists, the BTS, or on IRC, some of the perpetrators are also outside of the jurisdiction of DAM, which shows how DAM is not the tool for this
How about the DPL?
  • Talking about emergency catch alls, don't they have enough to do already?
Concentrating responsibility
  • Concentrating all responsibility on social issues on a single point creates a scapegoat: we're blamed for any conduct issue, and we're blamed for any action we take on conduct issues
    • also, when you are a small group you are personally identified with it. Taking action on a person may mean making a new enemy, and becoming a target for harassment, retaliation, or even just the general unwarranted hostility of someone who is left with an axe to grind
  • As long as responsibility is centralised, any action one takes as a response of one micro-aggression (or one micro-aggression too many) is an overreaction. Distributing that responsibility allows a finer granularity of actions to be taken
    • you don't call the police to tell someone they're being annoying at the pub: the people at the pub will tell you you're being annoying, and the police is called if you want to beat them up in response
  • We are also a community where we have no tool to give feedback to posts, so it still looks good to nitpick stupid details with smart-looking tranchant one-liners, or elaborate confrontational put-downs, and one doesn't get the feedback of "that did not help". Compare with discussing https://salsa.debian.org/debian/grow-your-ideas/ which does have this kind of feedback
    • the lack of moderation and enforcement makes the Debian community ideal for easy baiting, concern trolling, dog whistling, and related fun, and people not empowered can be so manipulated to troll those responsible
    • if you're fragile in Debian, people will play cat and mouse with you. It might be social awkwardness, or people taking themselves too serious, but it can easily become bullying, and with no feedback it's hard to tell and course correct
  • Since DAM and DPL are where the ball stops, everyone else in Debian can afford to let the ball drop.
  • More generally, if only one group is responsible, nobody else is
Empowering developers
  • Police alone does not make a community safe: a community makes a community safe.
  • DDs currently have no power to act besides complaining to DAM, or complaining to Community Team that then can only pass complaints on to DAM.
    • you could act directly, but currently nobody has your back if the (micro-)aggression then starts extending to you, too
  • From no power comes no responsibility. And yet, the safety of a community is sustainable only if it is the responsibility of every member of the community.
  • don't wait for DAM as the only group who can do something
  • people should be able to address issues in smaller groups, without escalation at project level
  • but people don't have the tools for that
  • I/we've shouldered this responsibility for far too long because nobody else was doing it, and it's time the whole Debian community gets its act together and picks up this responsibility as they should be. You don't get to not care just because there's a small number of people who is caring for you.
What needs to happen
  • distinguish DAM decisions from decisions that are more about vision and direction, and would require more representation
  • DAM warnings shouldn't belong in DAM
  • who is responsible for interpretation of the CoC?
  • deciding what to do about controversial people shouldn't belong in DAM
  • curation of the community shouldn't belong in DAM
  • can't do this via GRs, it's a mess to do a GR to decide how acceptable is a specific person's behaviour, and a lot of this requires more and more frequent micro-decisions than one'd do via GRs

24 June 2022

Kees Cook: finding binary differences

As part of the continuing work to replace 1-element arrays in the Linux kernel, it s very handy to show that a source change has had no executable code difference. For example, if you started with this:
struct foo  
    unsigned long flags;
    u32 length;
    u32 data[1];
 ;
void foo_init(int count)
 
    struct foo *instance;
    size_t bytes = sizeof(*instance) + sizeof(u32) * (count - 1);
    ...
    instance = kmalloc(bytes, GFP_KERNEL);
    ...
 ;
And you changed only the struct definition:
-    u32 data[1];
+    u32 data[];
The bytes calculation is going to be incorrect, since it is still subtracting 1 element s worth of space from the desired count. (And let s ignore for the moment the open-coded calculation that may end up with an arithmetic over/underflow here; that can be solved separately by using the struct_size() helper or the size_mul(), size_add(), etc family of helpers.) The missed adjustment to the size calculation is relatively easy to find in this example, but sometimes it s much less obvious how structure sizes might be woven into the code. I ve been checking for issues by using the fantastic diffoscope tool. It can produce a LOT of noise if you try to compare builds without keeping in mind the issues solved by reproducible builds, with some additional notes. I prepare my build with the known to disrupt code layout options disabled, but with debug info enabled:
$ KBF="KBUILD_BUILD_TIMESTAMP=1970-01-01 KBUILD_BUILD_USER=user KBUILD_BUILD_HOST=host KBUILD_BUILD_VERSION=1"
$ OUT=gcc
$ make $KBF O=$OUT allmodconfig
$ ./scripts/config --file $OUT/.config \
        -d GCOV_KERNEL -d KCOV -d GCC_PLUGINS -d IKHEADERS -d KASAN -d UBSAN \
        -d DEBUG_INFO_NONE -e DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
$ make $KBF O=$OUT olddefconfig
Then I build a stock target, saving the output in before . In this case, I m examining drivers/scsi/megaraid/:
$ make -jN $KBF O=$OUT drivers/scsi/megaraid/
$ mkdir -p $OUT/before
$ cp $OUT/drivers/scsi/megaraid/*.o $OUT/before/
Then I patch and build a modified target, saving the output in after :
$ vi the/source/code.c
$ make -jN $KBF O=$OUT drivers/scsi/megaraid/
$ mkdir -p $OUT/after
$ cp $OUT/drivers/scsi/megaraid/*.o $OUT/after/
And then run diffoscope:
$ diffoscope $OUT/before/ $OUT/after/
If diffoscope output reports nothing, then we re done. Usually, though, when source lines move around other stuff will shift too (e.g. WARN macros rely on line numbers, so the bug table may change contents a bit, etc), and diffoscope output will look noisy. To examine just the executable code, the command that diffoscope used is reported in the output, and we can run it directly, but with possibly shifted line numbers not reported. i.e. running objdump without --line-numbers:
$ ARGS="--disassemble --demangle --reloc --no-show-raw-insn --section=.text"
$ for i in $(cd $OUT/before && echo *.o); do
        echo $i
        diff -u <(objdump $ARGS $OUT/before/$i   sed "0,/^Disassembly/d") \
                <(objdump $ARGS $OUT/after/$i    sed "0,/^Disassembly/d")
done
If I see an unexpected difference, for example:
-    c120:      movq   $0x0,0x800(%rbx)
+    c120:      movq   $0x0,0x7f8(%rbx)
Then I'll search for the pattern with line numbers added to the objdump output:
$ vi <(objdump --line-numbers $ARGS $OUT/after/megaraid_sas_fp.o)
I'd search for "0x0,0x7f8", find the source file and line number above it, open that source file at that position, and look to see where something was being miscalculated:
$ vi drivers/scsi/megaraid/megaraid_sas_fp.c +329
Once tracked down, I'd start over at the "patch and build a modified target" step above, repeating until there were no differences. For example, in the starting example, I'd also need to make this change:
-    size_t bytes = sizeof(*instance) + sizeof(u32) * (count - 1);
+    size_t bytes = sizeof(*instance) + sizeof(u32) * count;
Though, as hinted earlier, better yet would be:
-    size_t bytes = sizeof(*instance) + sizeof(u32) * (count - 1);
+    size_t bytes = struct_size(instance, data, count);
But sometimes adding the helper usage will add binary output differences since they're performing overflow checking that might saturate at SIZE_MAX. To help with patch clarity, those changes can be done separately from fixing the array declaration.

2022, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

17 June 2022

Antoine Beaupr : Matrix notes

I have some concerns about Matrix (the protocol, not the movie that came out recently, although I do have concerns about that as well). I've been watching the project for a long time, and it seems more a promising alternative to many protocols like IRC, XMPP, and Signal. This review may sound a bit negative, because it focuses on those concerns. I am the operator of an IRC network and people keep asking me to bridge it with Matrix. I have myself considered just giving up on IRC and converting to Matrix. This space is a living document exploring my research of that problem space. The TL;DR: is that no, I'm not setting up a bridge just yet, and I'm still on IRC. This article was written over the course of the last three months, but I have been watching the Matrix project for years (my logs seem to say 2016 at least). The article is rather long. It will likely take you half an hour to read, so copy this over to your ebook reader, your tablet, or dead trees, and lean back and relax as I show you around the Matrix. Or, alternatively, just jump to a section that interest you, most likely the conclusion.

Introduction to Matrix Matrix is an "open standard for interoperable, decentralised, real-time communication over IP. It can be used to power Instant Messaging, VoIP/WebRTC signalling, Internet of Things communication - or anywhere you need a standard HTTP API for publishing and subscribing to data whilst tracking the conversation history". It's also (when compared with XMPP) "an eventually consistent global JSON database with an HTTP API and pubsub semantics - whilst XMPP can be thought of as a message passing protocol." According to their FAQ, the project started in 2014, has about 20,000 servers, and millions of users. Matrix works over HTTPS but over a special port: 8448.

Security and privacy I have some concerns about the security promises of Matrix. It's advertised as a "secure" with "E2E [end-to-end] encryption", but how does it actually work?

Data retention defaults One of my main concerns with Matrix is data retention, which is a key part of security in a threat model where (for example) an hostile state actor wants to surveil your communications and can seize your devices. On IRC, servers don't actually keep messages all that long: they pass them along to other servers and clients as fast as they can, only keep them in memory, and move on to the next message. There are no concerns about data retention on messages (and their metadata) other than the network layer. (I'm ignoring the issues with user registration, which is a separate, if valid, concern.) Obviously, an hostile server could log everything passing through it, but IRC federations are normally tightly controlled. So, if you trust your IRC operators, you should be fairly safe. Obviously, clients can (and often do, even if OTR is configured!) log all messages, but this is generally not the default. Irssi, for example, does not log by default. IRC bouncers are more likely to log to disk, of course, to be able to do what they do. Compare this to Matrix: when you send a message to a Matrix homeserver, that server first stores it in its internal SQL database. Then it will transmit that message to all clients connected to that server and room, and to all other servers that have clients connected to that room. Those remote servers, in turn, will keep a copy of that message and all its metadata in their own database, by default forever. On encrypted rooms those messages are encrypted, but not their metadata. There is a mechanism to expire entries in Synapse, but it is not enabled by default. So one should generally assume that a message sent on Matrix is never expired.

GDPR in the federation But even if that setting was enabled by default, how do you control it? This is a fundamental problem of the federation: if any user is allowed to join a room (which is the default), those user's servers will log all content and metadata from that room. That includes private, one-on-one conversations, since those are essentially rooms as well. In the context of the GDPR, this is really tricky: who is the responsible party (known as the "data controller") here? It's basically any yahoo who fires up a home server and joins a room. In a federated network, one has to wonder whether GDPR enforcement is even possible at all. But in Matrix in particular, if you want to enforce your right to be forgotten in a given room, you would have to:
  1. enumerate all the users that ever joined the room while you were there
  2. discover all their home servers
  3. start a GDPR procedure against all those servers
I recognize this is a hard problem to solve while still keeping an open ecosystem. But I believe that Matrix should have much stricter defaults towards data retention than right now. Message expiry should be enforced by default, for example. (Note that there are also redaction policies that could be used to implement part of the GDPR automatically, see the privacy policy discussion below on that.) Also keep in mind that, in the brave new peer-to-peer world that Matrix is heading towards, the boundary between server and client is likely to be fuzzier, which would make applying the GDPR even more difficult. Update: this comment links to this post (in german) which apparently studied the question and concluded that Matrix is not GDPR-compliant. In fact, maybe Synapse should be designed so that there's no configurable flag to turn off data retention. A bit like how most system loggers in UNIX (e.g. syslog) come with a log retention system that typically rotate logs after a few weeks or month. Historically, this was designed to keep hard drives from filling up, but it also has the added benefit of limiting the amount of personal information kept on disk in this modern day. (Arguably, syslog doesn't rotate logs on its own, but, say, Debian GNU/Linux, as an installed system, does have log retention policies well defined for installed packages, and those can be discussed. And "no expiry" is definitely a bug.

Matrix.org privacy policy When I first looked at Matrix, five years ago, Element.io was called Riot.im and had a rather dubious privacy policy:
We currently use cookies to support our use of Google Analytics on the Website and Service. Google Analytics collects information about how you use the Website and Service. [...] This helps us to provide you with a good experience when you browse our Website and use our Service and also allows us to improve our Website and our Service.
When I asked Matrix people about why they were using Google Analytics, they explained this was for development purposes and they were aiming for velocity at the time, not privacy (paraphrasing here). They also included a "free to snitch" clause:
If we are or believe that we are under a duty to disclose or share your personal data, we will do so in order to comply with any legal obligation, the instructions or requests of a governmental authority or regulator, including those outside of the UK.
Those are really broad terms, above and beyond what is typically expected legally. Like the current retention policies, such user tracking and ... "liberal" collaboration practices with the state set a bad precedent for other home servers. Thankfully, since the above policy was published (2017), the GDPR was "implemented" (2018) and it seems like both the Element.io privacy policy and the Matrix.org privacy policy have been somewhat improved since. Notable points of the new privacy policies:
  • 2.3.1.1: the "federation" section actually outlines that "Federated homeservers and Matrix clients which respect the Matrix protocol are expected to honour these controls and redaction/erasure requests, but other federated homeservers are outside of the span of control of Element, and we cannot guarantee how this data will be processed"
  • 2.6: users under the age of 16 should not use the matrix.org service
  • 2.10: Upcloud, Mythic Beast, Amazon, and CloudFlare possibly have access to your data (it's nice to at least mention this in the privacy policy: many providers don't even bother admitting to this kind of delegation)
  • Element 2.2.1: mentions many more third parties (Twilio, Stripe, Quaderno, LinkedIn, Twitter, Google, Outplay, PipeDrive, HubSpot, Posthog, Sentry, and Matomo (phew!) used when you are paying Matrix.org for hosting
I'm not super happy with all the trackers they have on the Element platform, but then again you don't have to use that service. Your favorite homeserver (assuming you are not on Matrix.org) probably has their own Element deployment, hopefully without all that garbage. Overall, this is all a huge improvement over the previous privacy policy, so hats off to the Matrix people for figuring out a reasonable policy in such a tricky context. I particularly like this bit:
We will forget your copy of your data upon your request. We will also forward your request to be forgotten onto federated homeservers. However - these homeservers are outside our span of control, so we cannot guarantee they will forget your data.
It's great they implemented those mechanisms and, after all, if there's an hostile party in there, nothing can prevent them from using screenshots to just exfiltrate your data away from the client side anyways, even with services typically seen as more secure, like Signal. As an aside, I also appreciate that Matrix.org has a fairly decent code of conduct, based on the TODO CoC which checks all the boxes in the geekfeminism wiki.

Metadata handling Overall, privacy protections in Matrix mostly concern message contents, not metadata. In other words, who's talking with who, when and from where is not well protected. Compared to a tool like Signal, which goes through great lengths to anonymize that data with features like private contact discovery, disappearing messages, sealed senders, and private groups, Matrix is definitely behind. (Note: there is an issue open about message lifetimes in Element since 2020, but it's not at even at the MSC stage yet.) This is a known issue (opened in 2019) in Synapse, but this is not just an implementation issue, it's a flaw in the protocol itself. Home servers keep join/leave of all rooms, which gives clear text information about who is talking to. Synapse logs may also contain privately identifiable information that home server admins might not be aware of in the first place. Those log rotation policies are separate from the server-level retention policy, which may be confusing for a novice sysadmin. Combine this with the federation: even if you trust your home server to do the right thing, the second you join a public room with third-party home servers, those ideas kind of get thrown out because those servers can do whatever they want with that information. Again, a problem that is hard to solve in any federation. To be fair, IRC doesn't have a great story here either: any client knows not only who's talking to who in a room, but also typically their client IP address. Servers can (and often do) obfuscate this, but often that obfuscation is trivial to reverse. Some servers do provide "cloaks" (sometimes automatically), but that's kind of a "slap-on" solution that actually moves the problem elsewhere: now the server knows a little more about the user. Overall, I would worry much more about a Matrix home server seizure than a IRC or Signal server seizure. Signal does get subpoenas, and they can only give out a tiny bit of information about their users: their phone number, and their registration, and last connection date. Matrix carries a lot more information in its database.

Amplification attacks on URL previews I (still!) run an Icecast server and sometimes share links to it on IRC which, obviously, also ends up on (more than one!) Matrix home servers because some people connect to IRC using Matrix. This, in turn, means that Matrix will connect to that URL to generate a link preview. I feel this outlines a security issue, especially because those sockets would be kept open seemingly forever. I tried to warn the Matrix security team but somehow, I don't think this issue was taken very seriously. Here's the disclosure timeline:
  • January 18: contacted Matrix security
  • January 19: response: already reported as a bug
  • January 20: response: can't reproduce
  • January 31: timeout added, considered solved
  • January 31: I respond that I believe the security issue is underestimated, ask for clearance to disclose
  • February 1: response: asking for two weeks delay after the next release (1.53.0) including another patch, presumably in two weeks' time
  • February 22: Matrix 1.53.0 released
  • April 14: I notice the release, ask for clearance again
  • April 14: response: referred to the public disclosure
There are a couple of problems here:
  1. the bug was publicly disclosed in September 2020, and not considered a security issue until I notified them, and even then, I had to insist
  2. no clear disclosure policy timeline was proposed or seems established in the project (there is a security disclosure policy but it doesn't include any predefined timeline)
  3. I wasn't informed of the disclosure
  4. the actual solution is a size limit (10MB, already implemented), a time limit (30 seconds, implemented in PR 11784), and a content type allow list (HTML, "media" or JSON, implemented in PR 11936), and I'm not sure it's adequate
  5. (pure vanity:) I did not make it to their Hall of fame
I'm not sure those solutions are adequate because they all seem to assume a single home server will pull that one URL for a little while then stop. But in a federated network, many (possibly thousands) home servers may be connected in a single room at once. If an attacker drops a link into such a room, all those servers would connect to that link all at once. This is an amplification attack: a small amount of traffic will generate a lot more traffic to a single target. It doesn't matter there are size or time limits: the amplification is what matters here. It should also be noted that clients that generate link previews have more amplification because they are more numerous than servers. And of course, the default Matrix client (Element) does generate link previews as well. That said, this is possibly not a problem specific to Matrix: any federated service that generates link previews may suffer from this. I'm honestly not sure what the solution is here. Maybe moderation? Maybe link previews are just evil? All I know is there was this weird bug in my Icecast server and I tried to ring the bell about it, and it feels it was swept under the rug. Somehow I feel this is bound to blow up again in the future, even with the current mitigation.

Moderation In Matrix like elsewhere, Moderation is a hard problem. There is a detailed moderation guide and much of this problem space is actively worked on in Matrix right now. A fundamental problem with moderating a federated space is that a user banned from a room can rejoin the room from another server. This is why spam is such a problem in Email, and why IRC networks have stopped federating ages ago (see the IRC history for that fascinating story).

The mjolnir bot The mjolnir moderation bot is designed to help with some of those things. It can kick and ban users, redact all of a user's message (as opposed to one by one), all of this across multiple rooms. It can also subscribe to a federated block list published by matrix.org to block known abusers (users or servers). Bans are pretty flexible and can operate at the user, room, or server level. Matrix people suggest making the bot admin of your channels, because you can't take back admin from a user once given.

The command-line tool There's also a new command line tool designed to do things like:
  • System notify users (all users/users from a list, specific user)
  • delete sessions/devices not seen for X days
  • purge the remote media cache
  • select rooms with various criteria (external/local/empty/created by/encrypted/cleartext)
  • purge history of theses rooms
  • shutdown rooms
This tool and Mjolnir are based on the admin API built into Synapse.

Rate limiting Synapse has pretty good built-in rate-limiting which blocks repeated login, registration, joining, or messaging attempts. It may also end up throttling servers on the federation based on those settings.

Fundamental federation problems Because users joining a room may come from another server, room moderators are at the mercy of the registration and moderation policies of those servers. Matrix is like IRC's +R mode ("only registered users can join") by default, except that anyone can register their own homeserver, which makes this limited. Server admins can block IP addresses and home servers, but those tools are not easily available to room admins. There is an API (m.room.server_acl in /devtools) but it is not reliable (thanks Austin Huang for the clarification). Matrix has the concept of guest accounts, but it is not used very much, and virtually no client or homeserver supports it. This contrasts with the way IRC works: by default, anyone can join an IRC network even without authentication. Some channels require registration, but in general you are free to join and look around (until you get blocked, of course). I have seen anecdotal evidence (CW: Twitter, nitter link) that "moderating bridges is hell", and I can imagine why. Moderation is already hard enough on one federation, when you bridge a room with another network, you inherit all the problems from that network but without the entire abuse control tools from the original network's API...

Room admins Matrix, in particular, has the problem that room administrators (which have the power to redact messages, ban users, and promote other users) are bound to their Matrix ID which is, in turn, bound to their home servers. This implies that a home server administrators could (1) impersonate a given user and (2) use that to hijack the room. So in practice, the home server is the trust anchor for rooms, not the user themselves. That said, if server B administrator hijack user joe on server B, they will hijack that room on that specific server. This will not (necessarily) affect users on the other servers, as servers could refuse parts of the updates or ban the compromised account (or server). It does seem like a major flaw that room credentials are bound to Matrix identifiers, as opposed to the E2E encryption credentials. In an encrypted room even with fully verified members, a compromised or hostile home server can still take over the room by impersonating an admin. That admin (or even a newly minted user) can then send events or listen on the conversations. This is even more frustrating when you consider that Matrix events are actually signed and therefore have some authentication attached to them, acting like some sort of Merkle tree (as it contains a link to previous events). That signature, however, is made from the homeserver PKI keys, not the client's E2E keys, which makes E2E feel like it has been "bolted on" later.

Availability While Matrix has a strong advantage over Signal in that it's decentralized (so anyone can run their own homeserver,), I couldn't find an easy way to run a "multi-primary" setup, or even a "redundant" setup (even if with a single primary backend), short of going full-on "replicate PostgreSQL and Redis data", which is not typically for the faint of heart.

How this works in IRC On IRC, it's quite easy to setup redundant nodes. All you need is:
  1. a new machine (with it's own public address with an open port)
  2. a shared secret (or certificate) between that machine and an existing one on the network
  3. a connect block on both servers
That's it: the node will join the network and people can connect to it as usual and share the same user/namespace as the rest of the network. The servers take care of synchronizing state: you do not need to worry about replicating a database server. (Now, experienced IRC people will know there's a catch here: IRC doesn't have authentication built in, and relies on "services" which are basically bots that authenticate users (I'm simplifying, don't nitpick). If that service goes down, the network still works, but then people can't authenticate, and they can start doing nasty things like steal people's identity if they get knocked offline. But still: basic functionality still works: you can talk in rooms and with users that are on the reachable network.)

User identities Matrix is more complicated. Each "home server" has its own identity namespace: a specific user (say @anarcat:matrix.org) is bound to that specific home server. If that server goes down, that user is completely disconnected. They could register a new account elsewhere and reconnect, but then they basically lose all their configuration: contacts, joined channels are all lost. (Also notice how the Matrix IDs don't look like a typical user address like an email in XMPP. They at least did their homework and got the allocation for the scheme.)

Rooms Users talk to each other in "rooms", even in one-to-one communications. (Rooms are also used for other things like "spaces", they're basically used for everything, think "everything is a file" kind of tool.) For rooms, home servers act more like IRC nodes in that they keep a local state of the chat room and synchronize it with other servers. Users can keep talking inside a room if the server that originally hosts the room goes down. Rooms can have a local, server-specific "alias" so that, say, #room:matrix.org is also visible as #room:example.com on the example.com home server. Both addresses refer to the same room underlying room. (Finding this in the Element settings is not obvious though, because that "alias" are actually called a "local address" there. So to create such an alias (in Element), you need to go in the room settings' "General" section, "Show more" in "Local address", then add the alias name (e.g. foo), and then that room will be available on your example.com homeserver as #foo:example.com.) So a room doesn't belong to a server, it belongs to the federation, and anyone can join the room from any serer (if the room is public, or if invited otherwise). You can create a room on server A and when a user from server B joins, the room will be replicated on server B as well. If server A fails, server B will keep relaying traffic to connected users and servers. A room is therefore not fundamentally addressed with the above alias, instead ,it has a internal Matrix ID, which basically a random string. It has a server name attached to it, but that was made just to avoid collisions. That can get a little confusing. For example, the #fractal:gnome.org room is an alias on the gnome.org server, but the room ID is !hwiGbsdSTZIwSRfybq:matrix.org. That's because the room was created on matrix.org, but the preferred branding is gnome.org now. As an aside, rooms, by default, live forever, even after the last user quits. There's an admin API to delete rooms and a tombstone event to redirect to another one, but neither have a GUI yet. The latter is part of MSC1501 ("Room version upgrades") which allows a room admin to close a room, with a message and a pointer to another room.

Spaces Discovering rooms can be tricky: there is a per-server room directory, but Matrix.org people are trying to deprecate it in favor of "Spaces". Room directories were ripe for abuse: anyone can create a room, so anyone can show up in there. It's possible to restrict who can add aliases, but anyways directories were seen as too limited. In contrast, a "Space" is basically a room that's an index of other rooms (including other spaces), so existing moderation and administration mechanism that work in rooms can (somewhat) work in spaces as well. This enables a room directory that works across federation, regardless on which server they were originally created. New users can be added to a space or room automatically in Synapse. (Existing users can be told about the space with a server notice.) This gives admins a way to pre-populate a list of rooms on a server, which is useful to build clusters of related home servers, providing some sort of redundancy, at the room -- not user -- level.

Home servers So while you can workaround a home server going down at the room level, there's no such thing at the home server level, for user identities. So if you want those identities to be stable in the long term, you need to think about high availability. One limitation is that the domain name (e.g. matrix.example.com) must never change in the future, as renaming home servers is not supported. The documentation used to say you could "run a hot spare" but that has been removed. Last I heard, it was not possible to run a high-availability setup where multiple, separate locations could replace each other automatically. You can have high performance setups where the load gets distributed among workers, but those are based on a shared database (Redis and PostgreSQL) backend. So my guess is it would be possible to create a "warm" spare server of a matrix home server with regular PostgreSQL replication, but that is not documented in the Synapse manual. This sort of setup would also not be useful to deal with networking issues or denial of service attacks, as you will not be able to spread the load over multiple network locations easily. Redis and PostgreSQL heroes are welcome to provide their multi-primary solution in the comments. In the meantime, I'll just point out this is a solution that's handled somewhat more gracefully in IRC, by having the possibility of delegating the authentication layer.

Delegations If you do not want to run a Matrix server yourself, it's possible to delegate the entire thing to another server. There's a server discovery API which uses the .well-known pattern (or SRV records, but that's "not recommended" and a bit confusing) to delegate that service to another server. Be warned that the server still needs to be explicitly configured for your domain. You can't just put:
  "m.server": "matrix.org:443"  
... on https://example.com/.well-known/matrix/server and start using @you:example.com as a Matrix ID. That's because Matrix doesn't support "virtual hosting" and you'd still be connecting to rooms and people with your matrix.org identity, not example.com as you would normally expect. This is also why you cannot rename your home server. The server discovery API is what allows servers to find each other. Clients, on the other hand, use the client-server discovery API: this is what allows a given client to find your home server when you type your Matrix ID on login.

Performance The high availability discussion brushed over the performance of Matrix itself, but let's now dig into that.

Horizontal scalability There were serious scalability issues of the main Matrix server, Synapse, in the past. So the Matrix team has been working hard to improve its design. Since Synapse 1.22 the home server can horizontally scale to multiple workers (see this blog post for details) which can make it easier to scale large servers.

Other implementations There are other promising home servers implementations from a performance standpoint (dendrite, Golang, entered beta in late 2020; conduit, Rust, beta; others), but none of those are feature-complete so there's a trade-off to be made there. Synapse is also adding a lot of feature fast, so it's an open question whether the others will ever catch up. (I have heard that Dendrite might actually surpass Synapse in features within a few years, which would put Synapse in a more "LTS" situation.)

Latency Matrix can feel slow sometimes. For example, joining the "Matrix HQ" room in Element (from matrix.debian.social) takes a few minutes and then fails. That is because the home server has to sync the entire room state when you join the room. There was promising work on this announced in the lengthy 2021 retrospective, and some of that work landed (partial sync) in the 1.53 release already. Other improvements coming include sliding sync, lazy loading over federation, and fast room joins. So that's actually something that could be fixed in the fairly short term. But in general, communication in Matrix doesn't feel as "snappy" as on IRC or even Signal. It's hard to quantify this without instrumenting a full latency test bed (for example the tools I used in the terminal emulators latency tests), but even just typing in a web browser feels slower than typing in a xterm or Emacs for me. Even in conversations, I "feel" people don't immediately respond as fast. In fact, this could be an interesting double-blind experiment to make: have people guess whether they are talking to a person on Matrix, XMPP, or IRC, for example. My theory would be that people could notice that Matrix users are slower, if only because of the TCP round-trip time each message has to take.

Transport Some courageous person actually made some tests of various messaging platforms on a congested network. His evaluation was basically:
  • Briar: uses Tor, so unusable except locally
  • Matrix: "struggled to send and receive messages", joining a room takes forever as it has to sync all history, "took 20-30 seconds for my messages to be sent and another 20 seconds for further responses"
  • XMPP: "worked in real-time, full encryption, with nearly zero lag"
So that was interesting. I suspect IRC would have also fared better, but that's just a feeling. Other improvements to the transport layer include support for websocket and the CoAP proxy work from 2019 (targeting 100bps links), but both seem stalled at the time of writing. The Matrix people have also announced the pinecone p2p overlay network which aims at solving large, internet-scale routing problems. See also this talk at FOSDEM 2022.

Usability

Onboarding and workflow The workflow for joining a room, when you use Element web, is not great:
  1. click on a link in a web browser
  2. land on (say) https://matrix.to/#/#matrix-dev:matrix.org
  3. offers "Element", yeah that's sounds great, let's click "Continue"
  4. land on https://app.element.io/#/room%2F%23matrix-dev%3Amatrix.org and then you need to register, aaargh
As you might have guessed by now, there is a specification to solve this, but web browsers need to adopt it as well, so that's far from actually being solved. At least browsers generally know about the matrix: scheme, it's just not exactly clear what they should do with it, especially when the handler is just another web page (e.g. Element web). In general, when compared with tools like Signal or WhatsApp, Matrix doesn't fare so well in terms of user discovery. I probably have some of my normal contacts that have a Matrix account as well, but there's really no way to know. It's kind of creepy when Signal tells you "this person is on Signal!" but it's also pretty cool that it works, and they actually implemented it pretty well. Registration is also less obvious: in Signal, the app confirms your phone number automatically. It's friction-less and quick. In Matrix, you need to learn about home servers, pick one, register (with a password! aargh!), and then setup encryption keys (not default), etc. It's a lot more friction. And look, I understand: giving away your phone number is a huge trade-off. I don't like it either. But it solves a real problem and makes encryption accessible to a ton more people. Matrix does have "identity servers" that can serve that purpose, but I don't feel confident sharing my phone number there. It doesn't help that the identity servers don't have private contact discovery: giving them your phone number is a more serious security compromise than with Signal. There's a catch-22 here too: because no one feels like giving away their phone numbers, no one does, and everyone assumes that stuff doesn't work anyways. Like it or not, Signal forcing people to divulge their phone number actually gives them critical mass that means actually a lot of my relatives are on Signal and I don't have to install crap like WhatsApp to talk with them.

5 minute clients evaluation Throughout all my tests I evaluated a handful of Matrix clients, mostly from Flathub because almost none of them are packaged in Debian. Right now I'm using Element, the flagship client from Matrix.org, in a web browser window, with the PopUp Window extension. This makes it look almost like a native app, and opens links in my main browser window (instead of a new tab in that separate window), which is nice. But I'm tired of buying memory to feed my web browser, so this indirection has to stop. Furthermore, I'm often getting completely logged off from Element, which means re-logging in, recovering my security keys, and reconfiguring my settings. That is extremely annoying. Coming from Irssi, Element is really "GUI-y" (pronounced "gooey"). Lots of clickety happening. To mark conversations as read, in particular, I need to click-click-click on all the tabs that have some activity. There's no "jump to latest message" or "mark all as read" functionality as far as I could tell. In Irssi the former is built-in (alt-a) and I made a custom /READ command for the latter:
/ALIAS READ script exec \$_->activity(0) for Irssi::windows
And yes, that's a Perl script in my IRC client. I am not aware of any Matrix client that does stuff like that, except maybe Weechat, if we can call it a Matrix client, or Irssi itself, now that it has a Matrix plugin (!). As for other clients, I have looked through the Matrix Client Matrix (confusing right?) to try to figure out which one to try, and, even after selecting Linux as a filter, the chart is just too wide to figure out anything. So I tried those, kind of randomly:
  • Fractal
  • Mirage
  • Nheko
  • Quaternion
Unfortunately, I lost my notes on those, I don't actually remember which one did what. I still have a session open with Mirage, so I guess that means it's the one I preferred, but I remember they were also all very GUI-y. Maybe I need to look at weechat-matrix or gomuks. At least Weechat is scriptable so I could continue playing the power-user. Right now my strategy with messaging (and that includes microblogging like Twitter or Mastodon) is that everything goes through my IRC client, so Weechat could actually fit well in there. Going with gomuks, on the other hand, would mean running it in parallel with Irssi or ... ditching IRC, which is a leap I'm not quite ready to take just yet. Oh, and basically none of those clients (except Nheko and Element) support VoIP, which is still kind of a second-class citizen in Matrix. It does not support large multimedia rooms, for example: Jitsi was used for FOSDEM instead of the native videoconferencing system.

Bots This falls a little aside the "usability" section, but I didn't know where to put this... There's a few Matrix bots out there, and you are likely going to be able to replace your existing bots with Matrix bots. It's true that IRC has a long and impressive history with lots of various bots doing various things, but given how young Matrix is, there's still a good variety:
  • maubot: generic bot with tons of usual plugins like sed, dice, karma, xkcd, echo, rss, reminder, translate, react, exec, gitlab/github webhook receivers, weather, etc
  • opsdroid: framework to implement "chat ops" in Matrix, connects with Matrix, GitHub, GitLab, Shell commands, Slack, etc
  • matrix-nio: another framework, used to build lots more bots like:
    • hemppa: generic bot with various functionality like weather, RSS feeds, calendars, cron jobs, OpenStreetmaps lookups, URL title snarfing, wolfram alpha, astronomy pic of the day, Mastodon bridge, room bridging, oh dear
    • devops: ping, curl, etc
    • podbot: play podcast episodes from AntennaPod
    • cody: Python, Ruby, Javascript REPL
    • eno: generic bot, "personal assistant"
  • mjolnir: moderation bot
  • hookshot: bridge with GitLab/GitHub
  • matrix-monitor-bot: latency monitor
One thing I haven't found an equivalent for is Debian's MeetBot. There's an archive bot but it doesn't have topics or a meeting chair, or HTML logs.

Working on Matrix As a developer, I find Matrix kind of intimidating. The specification is huge. The official specification itself looks somewhat digestable: it's only 6 APIs so that looks, at first, kind of reasonable. But whenever you start asking complicated questions about Matrix, you quickly fall into the Matrix Spec Change specification (which, yes, is a separate specification). And there are literally hundreds of MSCs flying around. It's hard to tell what's been adopted and what hasn't, and even harder to figure out if your specific client has implemented it. (One trendy answer to this problem is to "rewrite it in rust": Matrix are working on implementing a lot of those specifications in a matrix-rust-sdk that's designed to take the implementation details away from users.) Just taking the latest weekly Matrix report, you find that three new MSCs proposed, just last week! There's even a graph that shows the number of MSCs is progressing steadily, at 600+ proposals total, with the majority (300+) "new". I would guess the "merged" ones are at about 150. That's a lot of text which includes stuff like 3D worlds which, frankly, I don't think you should be working on when you have such important security and usability problems. (The internet as a whole, arguably, doesn't fare much better. RFC600 is a really obscure discussion about "INTERFACING AN ILLINOIS PLASMA TERMINAL TO THE ARPANET". Maybe that's how many MSCs will end up as well, left forgotten in the pits of history.) And that's the thing: maybe the Matrix people have a different objective than I have. They want to connect everything to everything, and make Matrix a generic transport for all sorts of applications, including virtual reality, collaborative editors, and so on. I just want secure, simple messaging. Possibly with good file transfers, and video calls. That it works with existing stuff is good, and it should be federated to remove the "Signal point of failure". So I'm a bit worried with the direction all those MSCs are taking, especially when you consider that clients other than Element are still struggling to keep up with basic features like end-to-end encryption or room discovery, never mind voice or spaces...

Conclusion Overall, Matrix is somehow in the space XMPP was a few years ago. It has a ton of features, pretty good clients, and a large community. It seems to have gained some of the momentum that XMPP has lost. It may have the most potential to replace Signal if something bad would happen to it (like, I don't know, getting banned or going nuts with cryptocurrency)... But it's really not there yet, and I don't see Matrix trying to get there either, which is a bit worrisome.

Looking back at history I'm also worried that we are repeating the errors of the past. The history of federated services is really fascinating:. IRC, FTP, HTTP, and SMTP were all created in the early days of the internet, and are all still around (except, arguably, FTP, which was removed from major browsers recently). All of them had to face serious challenges in growing their federation. IRC had numerous conflicts and forks, both at the technical level but also at the political level. The history of IRC is really something that anyone working on a federated system should study in detail, because they are bound to make the same mistakes if they are not familiar with it. The "short" version is:
  • 1988: Finnish researcher publishes first IRC source code
  • 1989: 40 servers worldwide, mostly universities
  • 1990: EFnet ("eris-free network") fork which blocks the "open relay", named Eris - followers of Eris form the A-net, which promptly dissolves itself, with only EFnet remaining
  • 1992: Undernet fork, which offered authentication ("services"), routing improvements and timestamp-based channel synchronisation
  • 1994: DALnet fork, from Undernet, again on a technical disagreement
  • 1995: Freenode founded
  • 1996: IRCnet forks from EFnet, following a flame war of historical proportion, splitting the network between Europe and the Americas
  • 1997: Quakenet founded
  • 1999: (XMPP founded)
  • 2001: 6 million users, OFTC founded
  • 2002: DALnet peaks at 136,000 users
  • 2003: IRC as a whole peaks at 10 million users, EFnet peaks at 141,000 users
  • 2004: (Facebook founded), Undernet peaks at 159,000 users
  • 2005: Quakenet peaks at 242,000 users, IRCnet peaks at 136,000 (Youtube founded)
  • 2006: (Twitter founded)
  • 2009: (WhatsApp, Pinterest founded)
  • 2010: (TextSecure AKA Signal, Instagram founded)
  • 2011: (Snapchat founded)
  • ~2013: Freenode peaks at ~100,000 users
  • 2016: IRCv3 standardisation effort started (TikTok founded)
  • 2021: Freenode self-destructs, Libera chat founded
  • 2022: Libera peaks at 50,000 users, OFTC peaks at 30,000 users
(The numbers were taken from the Wikipedia page and Netsplit.de. Note that I also include other networks launch in parenthesis for context.) Pretty dramatic, don't you think? Eventually, somehow, IRC became irrelevant for most people: few people are even aware of it now. With less than a million users active, it's smaller than Mastodon, XMPP, or Matrix at this point.1 If I were to venture a guess, I'd say that infighting, lack of a standardization body, and a somewhat annoying protocol meant the network could not grow. It's also possible that the decentralised yet centralised structure of IRC networks limited their reliability and growth. But large social media companies have also taken over the space: observe how IRC numbers peak around the time the wave of large social media companies emerge, especially Facebook (2.9B users!!) and Twitter (400M users).

Where the federated services are in history Right now, Matrix, and Mastodon (and email!) are at the "pre-EFnet" stage: anyone can join the federation. Mastodon has started working on a global block list of fascist servers which is interesting, but it's still an open federation. Right now, Matrix is totally open, but matrix.org publishes a (federated) block list of hostile servers (#matrix-org-coc-bl:matrix.org, yes, of course it's a room). Interestingly, Email is also in that stage, where there are block lists of spammers, and it's a race between those blockers and spammers. Large email providers, obviously, are getting closer to the EFnet stage: you could consider they only accept email from themselves or between themselves. It's getting increasingly hard to deliver mail to Outlook and Gmail for example, partly because of bias against small providers, but also because they are including more and more machine-learning tools to sort through email and those systems are, fundamentally, unknowable. It's not quite the same as splitting the federation the way EFnet did, but the effect is similar. HTTP has somehow managed to live in a parallel universe, as it's technically still completely federated: anyone can start a web server if they have a public IP address and anyone can connect to it. The catch, of course, is how you find the darn thing. Which is how Google became one of the most powerful corporations on earth, and how they became the gatekeepers of human knowledge online. I have only briefly mentioned XMPP here, and my XMPP fans will undoubtedly comment on that, but I think it's somewhere in the middle of all of this. It was co-opted by Facebook and Google, and both corporations have abandoned it to its fate. I remember fondly the days where I could do instant messaging with my contacts who had a Gmail account. Those days are gone, and I don't talk to anyone over Jabber anymore, unfortunately. And this is a threat that Matrix still has to face. It's also the threat Email is currently facing. On the one hand corporations like Facebook want to completely destroy it and have mostly succeeded: many people just have an email account to register on things and talk to their friends over Instagram or (lately) TikTok (which, I know, is not Facebook, but they started that fire). On the other hand, you have corporations like Microsoft and Google who are still using and providing email services because, frankly, you still do need email for stuff, just like fax is still around but they are more and more isolated in their own silo. At this point, it's only a matter of time they reach critical mass and just decide that the risk of allowing external mail coming in is not worth the cost. They'll simply flip the switch and work on an allow-list principle. Then we'll have closed the loop and email will be dead, just like IRC is "dead" now. I wonder which path Matrix will take. Could it liberate us from these vicious cycles? Update: this generated some discussions on lobste.rs.

  1. According to Wikipedia, there are currently about 500 distinct IRC networks operating, on about 1,000 servers, serving over 250,000 users. In contrast, Mastodon seems to be around 5 million users, Matrix.org claimed at FOSDEM 2021 to have about 28 million globally visible accounts, and Signal lays claim to over 40 million souls. XMPP claims to have "millions" of users on the xmpp.org homepage but the FAQ says they don't actually know. On the proprietary silo side of the fence, this page says
    • Facebook: 2.9 billion users
    • WhatsApp: 2B
    • Instagram: 1.4B
    • TikTok: 1B
    • Snapchat: 500M
    • Pinterest: 480M
    • Twitter: 397M
    Notable omission from that list: Youtube, with its mind-boggling 2.6 billion users... Those are not the kind of numbers you just "need to convince a brother or sister" to grow the network...

26 May 2022

Sergio Talens-Oliag: New Blog Config

As promised, on this post I m going to explain how I ve configured this blog using hugo, asciidoctor and the papermod theme, how I publish it using nginx, how I ve integrated the remark42 comment system and how I ve automated its publication using gitea and json2file-go. It is a long post, but I hope that at least parts of it can be interesting for some, feel free to ignore it if that is not your case

Hugo Configuration

Theme settingsThe site is using the PaperMod theme and as I m using asciidoctor to publish my content I ve adjusted the settings to improve how things are shown with it. The current config.yml file is the one shown below (probably some of the settings are not required nor being used right now, but I m including the current file, so this post will have always the latest version of it):
config.yml
baseURL: https://blogops.mixinet.net/
title: Mixinet BlogOps
paginate: 5
theme: PaperMod
destination: public/
enableInlineShortcodes: true
enableRobotsTXT: true
buildDrafts: false
buildFuture: false
buildExpired: false
enableEmoji: true
pygmentsUseClasses: true
minify:
  disableXML: true
  minifyOutput: true
languages:
  en:
    languageName: "English"
    description: "Mixinet BlogOps - https://blogops.mixinet.net/"
    author: "Sergio Talens-Oliag"
    weight: 1
    title: Mixinet BlogOps
    homeInfoParams:
      Title: "Sergio Talens-Oliag Technical Blog"
      Content: >
        ![Mixinet BlogOps](/images/mixinet-blogops.png)
    taxonomies:
      category: categories
      tag: tags
      series: series
    menu:
      main:
        - name: Archive
          url: archives
          weight: 5
        - name: Categories
          url: categories/
          weight: 10
        - name: Tags
          url: tags/
          weight: 10
        - name: Search
          url: search/
          weight: 15
outputs:
  home:
    - HTML
    - RSS
    - JSON
params:
  env: production
  defaultTheme: light
  disableThemeToggle: false
  ShowShareButtons: true
  ShowReadingTime: true
  disableSpecial1stPost: true
  disableHLJS: true
  displayFullLangName: true
  ShowPostNavLinks: true
  ShowBreadCrumbs: true
  ShowCodeCopyButtons: true
  ShowRssButtonInSectionTermList: true
  ShowFullTextinRSS: true
  ShowToc: true
  TocOpen: false
  comments: true
  remark42SiteID: "blogops"
  remark42Url: "/remark42"
  profileMode:
    enabled: false
    title: Sergio Talens-Oliag Technical Blog
    imageUrl: "/images/mixinet-blogops.png"
    imageTitle: Mixinet BlogOps
    buttons:
      - name: Archives
        url: archives
      - name: Categories
        url: categories
      - name: Tags
        url: tags
  socialIcons:
    - name: CV
      url: "https://www.uv.es/~sto/cv/"
    - name: Debian
      url: "https://people.debian.org/~sto/"
    - name: GitHub
      url: "https://github.com/sto/"
    - name: GitLab
      url: "https://gitlab.com/stalens/"
    - name: Linkedin
      url: "https://www.linkedin.com/in/sergio-talens-oliag/"
    - name: RSS
      url: "index.xml"
  assets:
    disableHLJS: true
    favicon: "/favicon.ico"
    favicon16x16:  "/favicon-16x16.png"
    favicon32x32:  "/favicon-32x32.png"
    apple_touch_icon:  "/apple-touch-icon.png"
    safari_pinned_tab:  "/safari-pinned-tab.svg"
  fuseOpts:
    isCaseSensitive: false
    shouldSort: true
    location: 0
    distance: 1000
    threshold: 0.4
    minMatchCharLength: 0
    keys: ["title", "permalink", "summary", "content"]
markup:
  asciidocExt:
    attributes:  
    backend: html5s
    extensions: ['asciidoctor-html5s','asciidoctor-diagram']
    failureLevel: fatal
    noHeaderOrFooter: true
    preserveTOC: false
    safeMode: unsafe
    sectionNumbers: false
    trace: false
    verbose: false
    workingFolderCurrent: true
privacy:
  vimeo:
    disabled: false
    simple: true
  twitter:
    disabled: false
    enableDNT: true
    simple: true
  instagram:
    disabled: false
    simple: true
  youtube:
    disabled: false
    privacyEnhanced: true
services:
  instagram:
    disableInlineCSS: true
  twitter:
    disableInlineCSS: true
security:
  exec:
    allow:
      - '^asciidoctor$'
      - '^dart-sass-embedded$'
      - '^go$'
      - '^npx$'
      - '^postcss$'
Some notes about the settings:
  • disableHLJS and assets.disableHLJS are set to true; we plan to use rouge on adoc and the inclusion of the hljs assets adds styles that collide with the ones used by rouge.
  • ShowToc is set to true and the TocOpen setting is set to false to make the ToC appear collapsed initially. My plan was to use the asciidoctor ToC, but after trying I believe that the theme one looks nice and I don t need to adjust styles, although it has some issues with the html5s processor (the admonition titles use <h6> and they are shown on the ToC, which is weird), to fix it I ve copied the layouts/partial/toc.html to my site repository and replaced the range of headings to end at 5 instead of 6 (in fact 5 still seems a lot, but as I don t think I ll use that heading level on the posts it doesn t really matter).
  • params.profileMode values are adjusted, but for now I ve left it disabled setting params.profileMode.enabled to false and I ve set the homeInfoParams to show more or less the same content with the latest posts under it (I ve added some styles to my custom.css style sheet to center the text and image of the first post to match the look and feel of the profile).
  • On the asciidocExt section I ve adjusted the backend to use html5s, I ve added the asciidoctor-html5s and asciidoctor-diagram extensions to asciidoctor and adjusted the workingFolderCurrent to true to make asciidoctor-diagram work right (haven t tested it yet).

Theme customisationsTo write in asciidoctor using the html5s processor I ve added some files to the assets/css/extended directory:
  1. As said before, I ve added the file assets/css/extended/custom.css to make the homeInfoParams look like the profile page and I ve also changed a little bit some theme styles to make things look better with the html5s output:
    custom.css
    /* Fix first entry alignment to make it look like the profile */
    .first-entry   text-align: center;  
    .first-entry img   display: inline;  
    /**
     * Remove margin for .post-content code and reduce padding to make it look
     * better with the asciidoctor html5s output.
     **/
    .post-content code   margin: auto 0; padding: 4px;  
  2. I ve also added the file assets/css/extended/adoc.css with some styles taken from the asciidoctor-default.css, see this blog post about the original file; mine is the same after formatting it with css-beautify and editing it to use variables for the colors to support light and dark themes:
    adoc.css
    /* AsciiDoctor*/
    table  
        border-collapse: collapse;
        border-spacing: 0
     
    .admonitionblock>table  
        border-collapse: separate;
        border: 0;
        background: none;
        width: 100%
     
    .admonitionblock>table td.icon  
        text-align: center;
        width: 80px
     
    .admonitionblock>table td.icon img  
        max-width: none
     
    .admonitionblock>table td.icon .title  
        font-weight: bold;
        font-family: "Open Sans", "DejaVu Sans", sans-serif;
        text-transform: uppercase
     
    .admonitionblock>table td.content  
        padding-left: 1.125em;
        padding-right: 1.25em;
        border-left: 1px solid #ddddd8;
        color: var(--primary)
     
    .admonitionblock>table td.content>:last-child>:last-child  
        margin-bottom: 0
     
    .admonitionblock td.icon [class^="fa icon-"]  
        font-size: 2.5em;
        text-shadow: 1px 1px 2px var(--secondary);
        cursor: default
     
    .admonitionblock td.icon .icon-note::before  
        content: "\f05a";
        color: var(--icon-note-color)
     
    .admonitionblock td.icon .icon-tip::before  
        content: "\f0eb";
        color: var(--icon-tip-color)
     
    .admonitionblock td.icon .icon-warning::before  
        content: "\f071";
        color: var(--icon-warning-color)
     
    .admonitionblock td.icon .icon-caution::before  
        content: "\f06d";
        color: var(--icon-caution-color)
     
    .admonitionblock td.icon .icon-important::before  
        content: "\f06a";
        color: var(--icon-important-color)
     
    .conum[data-value]  
        display: inline-block;
        color: #fff !important;
        background-color: rgba(100, 100, 0, .8);
        -webkit-border-radius: 100px;
        border-radius: 100px;
        text-align: center;
        font-size: .75em;
        width: 1.67em;
        height: 1.67em;
        line-height: 1.67em;
        font-family: "Open Sans", "DejaVu Sans", sans-serif;
        font-style: normal;
        font-weight: bold
     
    .conum[data-value] *  
        color: #fff !important
     
    .conum[data-value]+b  
        display: none
     
    .conum[data-value]::after  
        content: attr(data-value)
     
    pre .conum[data-value]  
        position: relative;
        top: -.125em
     
    b.conum *  
        color: inherit !important
     
    .conum:not([data-value]):empty  
        display: none
     
  3. The previous file uses variables from a partial copy of the theme-vars.css file that changes the highlighted code background color and adds the color definitions used by the admonitions:
    theme-vars.css
    :root  
        /* Solarized base2 */
        /* --hljs-bg: rgb(238, 232, 213); */
        /* Solarized base3 */
        /* --hljs-bg: rgb(253, 246, 227); */
        /* Solarized base02 */
        --hljs-bg: rgb(7, 54, 66);
        /* Solarized base03 */
        /* --hljs-bg: rgb(0, 43, 54); */
        /* Default asciidoctor theme colors */
        --icon-note-color: #19407c;
        --icon-tip-color: var(--primary);
        --icon-warning-color: #bf6900;
        --icon-caution-color: #bf3400;
        --icon-important-color: #bf0000
     
    .dark  
        --hljs-bg: rgb(7, 54, 66);
        /* Asciidoctor theme colors with tint for dark background */
        --icon-note-color: #3e7bd7;
        --icon-tip-color: var(--primary);
        --icon-warning-color: #ff8d03;
        --icon-caution-color: #ff7847;
        --icon-important-color: #ff3030
     
  4. The previous styles use font-awesome, so I ve downloaded its resources for version 4.7.0 (the one used by asciidoctor) storing the font-awesome.css into on the assets/css/extended dir (that way it is merged with the rest of .css files) and copying the fonts to the static/assets/fonts/ dir (will be served directly):
    FA_BASE_URL="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0"
    curl "$FA_BASE_URL/css/font-awesome.css" \
      > assets/css/extended/font-awesome.css
    for f in FontAwesome.otf fontawesome-webfont.eot \
      fontawesome-webfont.svg fontawesome-webfont.ttf \
      fontawesome-webfont.woff fontawesome-webfont.woff2; do
        curl "$FA_BASE_URL/fonts/$f" > "static/assets/fonts/$f"
    done
  5. As already said the default highlighter is disabled (it provided a css compatible with rouge) so we need a css to do the highlight styling; as rouge provides a way to export them, I ve created the assets/css/extended/rouge.css file with the thankful_eyes theme:
    rougify style thankful_eyes > assets/css/extended/rouge.css
  6. To support the use of the html5s backend with admonitions I ve added a variation of the example found on this blog post to assets/js/adoc-admonitions.js:
    adoc-admonitions.js
    // replace the default admonitions block with a table that uses a format
    // similar to the standard asciidoctor ... as we are using fa-icons here there
    // is no need to add the icons: font entry on the document.
    window.addEventListener('load', function ()  
      const admonitions = document.getElementsByClassName('admonition-block')
      for (let i = admonitions.length - 1; i >= 0; i--)  
        const elm = admonitions[i]
        const type = elm.classList[1]
        const title = elm.getElementsByClassName('block-title')[0];
    	const label = title.getElementsByClassName('title-label')[0]
    		.innerHTML.slice(0, -1);
        elm.removeChild(elm.getElementsByClassName('block-title')[0]);
        const text = elm.innerHTML
        const parent = elm.parentNode
        const tempDiv = document.createElement('div')
        tempDiv.innerHTML =  <div class="admonitionblock $ type ">
        <table>
          <tbody>
            <tr>
              <td class="icon">
                <i class="fa icon-$ type " title="$ label "></i>
              </td>
              <td class="content">
                $ text 
              </td>
            </tr>
          </tbody>
        </table>
      </div> 
        const input = tempDiv.childNodes[0]
        parent.replaceChild(input, elm)
       
     )
    and enabled its minified use on the layouts/partials/extend_footer.html file adding the following lines to it:
     - $admonitions := slice (resources.Get "js/adoc-admonitions.js")
        resources.Concat "assets/js/adoc-admonitions.js"   minify   fingerprint  
    <script defer crossorigin="anonymous" src="  $admonitions.RelPermalink  "
      integrity="  $admonitions.Data.Integrity  "></script>

Remark42 configurationTo integrate Remark42 with the PaperMod theme I ve created the file layouts/partials/comments.html with the following content based on the remark42 documentation, including extra code to sync the dark/light setting with the one set on the site:
comments.html
<div id="remark42"></div>
<script>
  var remark_config =  
    host:   .Site.Params.remark42Url  ,
    site_id:   .Site.Params.remark42SiteID  ,
    url:   .Permalink  ,
    locale:   .Site.Language.Lang  
   ;
  (function(c)  
    /* Adjust the theme using the local-storage pref-theme if set */
    if (localStorage.getItem("pref-theme") === "dark")  
      remark_config.theme = "dark";
      else if (localStorage.getItem("pref-theme") === "light")  
      remark_config.theme = "light";
     
    /* Add remark42 widget */
    for(var i = 0; i < c.length; i++) 
      var d = document, s = d.createElement('script');
      s.src = remark_config.host + '/web/' + c[i] +'.js';
      s.defer = true;
      (d.head   d.body).appendChild(s);
     
   )(remark_config.components   ['embed']);
</script>
In development I use it with anonymous comments enabled, but to avoid SPAM the production site uses social logins (for now I ve only enabled Github & Google, if someone requests additional services I ll check them, but those were the easy ones for me initially). To support theme switching with remark42 I ve also added the following inside the layouts/partials/extend_footer.html file:
 - if (not site.Params.disableThemeToggle)  
<script>
/* Function to change theme when the toggle button is pressed */
document.getElementById("theme-toggle").addEventListener("click", () =>  
  if (typeof window.REMARK42 != "undefined")  
    if (document.body.className.includes('dark'))  
      window.REMARK42.changeTheme('light');
      else  
      window.REMARK42.changeTheme('dark');
     
   
 );
</script>
 - end  
With this code if the theme-toggle button is pressed we change the remark42 theme before the PaperMod one (that s needed here only, on page loads the remark42 theme is synced with the main one using the code from the layouts/partials/comments.html shown earlier).

Development setupTo preview the site on my laptop I m using docker-compose with the following configuration:
docker-compose.yaml
version: "2"
services:
  hugo:
    build:
      context: ./docker/hugo-adoc
      dockerfile: ./Dockerfile
    image: sto/hugo-adoc
    container_name: hugo-adoc-blogops
    restart: always
    volumes:
      - .:/documents
    command: server --bind 0.0.0.0 -D -F
    user: $ APP_UID :$ APP_GID 
  nginx:
    image: nginx:latest
    container_name: nginx-blogops
    restart: always
    volumes:
      - ./nginx/default.conf:/etc/nginx/conf.d/default.conf
    ports:
      -  1313:1313
  remark42:
    build:
      context: ./docker/remark42
      dockerfile: ./Dockerfile
    image: sto/remark42
    container_name: remark42-blogops
    restart: always
    env_file:
      - ./.env
      - ./remark42/env.dev
    volumes:
      - ./remark42/var.dev:/srv/var
To run it properly we have to create the .env file with the current user ID and GID on the variables APP_UID and APP_GID (if we don t do it the files can end up being owned by a user that is not the same as the one running the services):
$ echo "APP_UID=$(id -u)\nAPP_GID=$(id -g)" > .env
The Dockerfile used to generate the sto/hugo-adoc is:
Dockerfile
FROM asciidoctor/docker-asciidoctor:latest
RUN gem install --no-document asciidoctor-html5s &&\
 apk update && apk add --no-cache curl libc6-compat &&\
 repo_path="gohugoio/hugo" &&\
 api_url="https://api.github.com/repos/$repo_path/releases/latest" &&\
 download_url="$(\
  curl -sL "$api_url"  \
  sed -n "s/^.*download_url\": \"\\(.*.extended.*Linux-64bit.tar.gz\)\"/\1/p"\
 )" &&\
 curl -sL "$download_url" -o /tmp/hugo.tgz &&\
 tar xf /tmp/hugo.tgz hugo &&\
 install hugo /usr/bin/ &&\
 rm -f hugo /tmp/hugo.tgz &&\
 /usr/bin/hugo version &&\
 apk del curl && rm -rf /var/cache/apk/*
# Expose port for live server
EXPOSE 1313
ENTRYPOINT ["/usr/bin/hugo"]
CMD [""]
If you review it you will see that I m using the docker-asciidoctor image as the base; the idea is that this image has all I need to work with asciidoctor and to use hugo I only need to download the binary from their latest release at github (as we are using an image based on alpine we also need to install the libc6-compat package, but once that is done things are working fine for me so far). The image does not launch the server by default because I don t want it to; in fact I use the same docker-compose.yml file to publish the site in production simply calling the container without the arguments passed on the docker-compose.yml file (see later). When running the containers with docker-compose up (or docker compose up if you have the docker-compose-plugin package installed) we also launch a nginx container and the remark42 service so we can test everything together. The Dockerfile for the remark42 image is the original one with an updated version of the init.sh script:
Dockerfile
FROM umputun/remark42:latest
COPY init.sh /init.sh
The updated init.sh is similar to the original, but allows us to use an APP_GID variable and updates the /etc/group file of the container so the files get the right user and group (with the original script the group is always 1001):
init.sh
#!/sbin/dinit /bin/sh
uid="$(id -u)"
if [ "$ uid " -eq "0" ]; then
  echo "init container"
  # set container's time zone
  cp "/usr/share/zoneinfo/$ TIME_ZONE " /etc/localtime
  echo "$ TIME_ZONE " >/etc/timezone
  echo "set timezone $ TIME_ZONE  ($(date))"
  # set UID & GID for the app
  if [ "$ APP_UID " ]   [ "$ APP_GID " ]; then
    [ "$ APP_UID " ]   APP_UID="1001"
    [ "$ APP_GID " ]   APP_GID="$ APP_UID "
    echo "set custom APP_UID=$ APP_UID  & APP_GID=$ APP_GID "
    sed -i "s/^app:x:1001:1001:/app:x:$ APP_UID :$ APP_GID :/" /etc/passwd
    sed -i "s/^app:x:1001:/app:x:$ APP_GID :/" /etc/group
  else
    echo "custom APP_UID and/or APP_GID not defined, using 1001:1001"
  fi
  chown -R app:app /srv /home/app
fi
echo "prepare environment"
# replace  % REMARK_URL %  by content of REMARK_URL variable
find /srv -regex '.*\.\(html\ js\ mjs\)$' -print \
  -exec sed -i "s % REMARK_URL % $ REMARK_URL  g"   \;
if [ -n "$ SITE_ID " ]; then
  #replace "site_id: 'remark'" by SITE_ID
  sed -i "s 'remark' '$ SITE_ID ' g" /srv/web/*.html
fi
echo "execute \"$*\""
if [ "$ uid " -eq "0" ]; then
  exec su-exec app "$@"
else
  exec "$@"
fi
The environment file used with remark42 for development is quite minimal:
env.dev
TIME_ZONE=Europe/Madrid
REMARK_URL=http://localhost:1313/remark42
SITE=blogops
SECRET=123456
ADMIN_SHARED_ID=sto
AUTH_ANON=true
EMOJI=true
And the nginx/default.conf file used to publish the service locally is simple too:
default.conf
server   
 listen 1313;
 server_name localhost;
 location /  
    proxy_pass http://hugo:1313;
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
  
 location /remark42/  
    rewrite /remark42/(.*) /$1 break;
    proxy_pass http://remark42:8080/;
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
   
 

Production setupThe VM where I m publishing the blog runs Debian GNU/Linux and uses binaries from local packages and applications packaged inside containers. To run the containers I m using docker-ce (I could have used podman instead, but I already had it installed on the machine, so I stayed with it). The binaries used on this project are included on the following packages from the main Debian repository:
  • git to clone & pull the repository,
  • jq to parse json files from shell scripts,
  • json2file-go to save the webhook messages to files,
  • inotify-tools to detect when new files are stored by json2file-go and launch scripts to process them,
  • nginx to publish the site using HTTPS and work as proxy for json2file-go and remark42 (I run it using a container),
  • task-spool to queue the scripts that update the deployment.
And I m using docker and docker compose from the debian packages on the docker repository:
  • docker-ce to run the containers,
  • docker-compose-plugin to run docker compose (it is a plugin, so no - in the name).

Repository checkoutTo manage the git repository I ve created a deploy key, added it to gitea and cloned the project on the /srv/blogops PATH (that route is owned by a regular user that has permissions to run docker, as I said before).

Compiling the site with hugoTo compile the site we are using the docker-compose.yml file seen before, to be able to run it first we build the container images and once we have them we launch hugo using docker compose run:
$ cd /srv/blogops
$ git pull
$ docker compose build
$ if [ -d "./public" ]; then rm -rf ./public; fi
$ docker compose run hugo --
The compilation leaves the static HTML on /srv/blogops/public (we remove the directory first because hugo does not clean the destination folder as jekyll does). The deploy script re-generates the site as described and moves the public directory to its final place for publishing.

Running remark42 with dockerOn the /srv/blogops/remark42 folder I have the following docker-compose.yml:
docker-compose.yml
version: "2"
services:
  remark42:
    build:
      context: ../docker/remark42
      dockerfile: ./Dockerfile
    image: sto/remark42
    env_file:
      - ../.env
      - ./env.prod
    container_name: remark42
    restart: always
    volumes:
      - ./var.prod:/srv/var
    ports:
      - 127.0.0.1:8042:8080
The ../.env file is loaded to get the APP_UID and APP_GID variables that are used by my version of the init.sh script to adjust file permissions and the env.prod file contains the rest of the settings for remark42, including the social network tokens (see the remark42 documentation for the available parameters, I don t include my configuration here because some of them are secrets).

Nginx configurationThe nginx configuration for the blogops.mixinet.net site is as simple as:
server  
  listen 443 ssl http2;
  server_name blogops.mixinet.net;
  ssl_certificate /etc/letsencrypt/live/blogops.mixinet.net/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/blogops.mixinet.net/privkey.pem;
  include /etc/letsencrypt/options-ssl-nginx.conf;
  ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
  access_log /var/log/nginx/blogops.mixinet.net-443.access.log;
  error_log  /var/log/nginx/blogops.mixinet.net-443.error.log;
  root /srv/blogops/nginx/public_html;
  location /  
    try_files $uri $uri/ =404;
   
  include /srv/blogops/nginx/remark42.conf;
 
server  
  listen 80 ;
  listen [::]:80 ;
  server_name blogops.mixinet.net;
  access_log /var/log/nginx/blogops.mixinet.net-80.access.log;
  error_log  /var/log/nginx/blogops.mixinet.net-80.error.log;
  if ($host = blogops.mixinet.net)  
    return 301 https://$host$request_uri;
   
  return 404;
 
On this configuration the certificates are managed by certbot and the server root directory is on /srv/blogops/nginx/public_html and not on /srv/blogops/public; the reason for that is that I want to be able to compile without affecting the running site, the deployment script generates the site on /srv/blogops/public and if all works well we rename folders to do the switch, making the change feel almost atomic.

json2file-go configurationAs I have a working WireGuard VPN between the machine running gitea at my home and the VM where the blog is served, I m going to configure the json2file-go to listen for connections on a high port using a self signed certificate and listening on IP addresses only reachable through the VPN. To do it we create a systemd socket to run json2file-go and adjust its configuration to listen on a private IP (we use the FreeBind option on its definition to be able to launch the service even when the IP is not available, that is, when the VPN is down). The following script can be used to set up the json2file-go configuration:
setup-json2file.sh
#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
BASE_DIR="/srv/blogops/webhook"
J2F_DIR="$BASE_DIR/json2file"
TLS_DIR="$BASE_DIR/tls"
J2F_SERVICE_NAME="json2file-go"
J2F_SERVICE_DIR="/etc/systemd/system/json2file-go.service.d"
J2F_SERVICE_OVERRIDE="$J2F_SERVICE_DIR/override.conf"
J2F_SOCKET_DIR="/etc/systemd/system/json2file-go.socket.d"
J2F_SOCKET_OVERRIDE="$J2F_SOCKET_DIR/override.conf"
J2F_BASEDIR_FILE="/etc/json2file-go/basedir"
J2F_DIRLIST_FILE="/etc/json2file-go/dirlist"
J2F_CRT_FILE="/etc/json2file-go/certfile"
J2F_KEY_FILE="/etc/json2file-go/keyfile"
J2F_CRT_PATH="$TLS_DIR/crt.pem"
J2F_KEY_PATH="$TLS_DIR/key.pem"
# ----
# MAIN
# ----
# Install packages used with json2file for the blogops site
sudo apt update
sudo apt install -y json2file-go uuid
if [ -z "$(type mkcert)" ]; then
  sudo apt install -y mkcert
fi
sudo apt clean
# Configuration file values
J2F_USER="$(id -u)"
J2F_GROUP="$(id -g)"
J2F_DIRLIST="blogops:$(uuid)"
J2F_LISTEN_STREAM="172.31.31.1:4443"
# Configure json2file
[ -d "$J2F_DIR" ]   mkdir "$J2F_DIR"
sudo sh -c "echo '$J2F_DIR' >'$J2F_BASEDIR_FILE'"
[ -d "$TLS_DIR" ]   mkdir "$TLS_DIR"
if [ ! -f "$J2F_CRT_PATH" ]   [ ! -f "$J2F_KEY_PATH" ]; then
  mkcert -cert-file "$J2F_CRT_PATH" -key-file "$J2F_KEY_PATH" "$(hostname -f)"
fi
sudo sh -c "echo '$J2F_CRT_PATH' >'$J2F_CRT_FILE'"
sudo sh -c "echo '$J2F_KEY_PATH' >'$J2F_KEY_FILE'"
sudo sh -c "cat >'$J2F_DIRLIST_FILE'" <<EOF
$(echo "$J2F_DIRLIST"   tr ';' '\n')
EOF
# Service override
[ -d "$J2F_SERVICE_DIR" ]   sudo mkdir "$J2F_SERVICE_DIR"
sudo sh -c "cat >'$J2F_SERVICE_OVERRIDE'" <<EOF
[Service]
User=$J2F_USER
Group=$J2F_GROUP
EOF
# Socket override
[ -d "$J2F_SOCKET_DIR" ]   sudo mkdir "$J2F_SOCKET_DIR"
sudo sh -c "cat >'$J2F_SOCKET_OVERRIDE'" <<EOF
[Socket]
# Set FreeBind to listen on missing addresses (the VPN can be down sometimes)
FreeBind=true
# Set ListenStream to nothing to clear its value and add the new value later
ListenStream=
ListenStream=$J2F_LISTEN_STREAM
EOF
# Restart and enable service
sudo systemctl daemon-reload
sudo systemctl stop "$J2F_SERVICE_NAME"
sudo systemctl start "$J2F_SERVICE_NAME"
sudo systemctl enable "$J2F_SERVICE_NAME"
# ----
# vim: ts=2:sw=2:et:ai:sts=2
Warning: The script uses mkcert to create the temporary certificates, to install the package on bullseye the backports repository must be available.

Gitea configurationTo make gitea use our json2file-go server we go to the project and enter into the hooks/gitea/new page, once there we create a new webhook of type gitea and set the target URL to https://172.31.31.1:4443/blogops and on the secret field we put the token generated with uuid by the setup script:
sed -n -e 's/blogops://p' /etc/json2file-go/dirlist
The rest of the settings can be left as they are:
  • Trigger on: Push events
  • Branch filter: *
Warning: We are using an internal IP and a self signed certificate, that means that we have to review that the webhook section of the app.ini of our gitea server allows us to call the IP and skips the TLS verification (you can see the available options on the gitea documentation). The [webhook] section of my server looks like this:
[webhook]
ALLOWED_HOST_LIST=private
SKIP_TLS_VERIFY=true
Once we have the webhook configured we can try it and if it works our json2file server will store the file on the /srv/blogops/webhook/json2file/blogops/ folder.

The json2file spooler scriptWith the previous configuration our system is ready to receive webhook calls from gitea and store the messages on files, but we have to do something to process those files once they are saved in our machine. An option could be to use a cronjob to look for new files, but we can do better on Linux using inotify we will use the inotifywait command from inotify-tools to watch the json2file output directory and execute a script each time a new file is moved inside it or closed after writing (IN_CLOSE_WRITE and IN_MOVED_TO events). To avoid concurrency problems we are going to use task-spooler to launch the scripts that process the webhooks using a queue of length 1, so they are executed one by one in a FIFO queue. The spooler script is this:
blogops-spooler.sh
#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
BASE_DIR="/srv/blogops/webhook"
BIN_DIR="$BASE_DIR/bin"
TSP_DIR="$BASE_DIR/tsp"
WEBHOOK_COMMAND="$BIN_DIR/blogops-webhook.sh"
# ---------
# FUNCTIONS
# ---------
queue_job()  
  echo "Queuing job to process file '$1'"
  TMPDIR="$TSP_DIR" TS_SLOTS="1" TS_MAXFINISHED="10" \
    tsp -n "$WEBHOOK_COMMAND" "$1"
 
# ----
# MAIN
# ----
INPUT_DIR="$1"
if [ ! -d "$INPUT_DIR" ]; then
  echo "Input directory '$INPUT_DIR' does not exist, aborting!"
  exit 1
fi
[ -d "$TSP_DIR" ]   mkdir "$TSP_DIR"
echo "Processing existing files under '$INPUT_DIR'"
find "$INPUT_DIR" -type f   sort   while read -r _filename; do
  queue_job "$_filename"
done
# Use inotifywatch to process new files
echo "Watching for new files under '$INPUT_DIR'"
inotifywait -q -m -e close_write,moved_to --format "%w%f" -r "$INPUT_DIR"  
  while read -r _filename; do
    queue_job "$_filename"
  done
# ----
# vim: ts=2:sw=2:et:ai:sts=2
To run it as a daemon we install it as a systemd service using the following script:
setup-spooler.sh
#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
BASE_DIR="/srv/blogops/webhook"
BIN_DIR="$BASE_DIR/bin"
J2F_DIR="$BASE_DIR/json2file"
SPOOLER_COMMAND="$BIN_DIR/blogops-spooler.sh '$J2F_DIR'"
SPOOLER_SERVICE_NAME="blogops-j2f-spooler"
SPOOLER_SERVICE_FILE="/etc/systemd/system/$SPOOLER_SERVICE_NAME.service"
# Configuration file values
J2F_USER="$(id -u)"
J2F_GROUP="$(id -g)"
# ----
# MAIN
# ----
# Install packages used with the webhook processor
sudo apt update
sudo apt install -y inotify-tools jq task-spooler
sudo apt clean
# Configure process service
sudo sh -c "cat > $SPOOLER_SERVICE_FILE" <<EOF
[Install]
WantedBy=multi-user.target
[Unit]
Description=json2file processor for $J2F_USER
After=docker.service
[Service]
Type=simple
User=$J2F_USER
Group=$J2F_GROUP
ExecStart=$SPOOLER_COMMAND
EOF
# Restart and enable service
sudo systemctl daemon-reload
sudo systemctl stop "$SPOOLER_SERVICE_NAME"   true
sudo systemctl start "$SPOOLER_SERVICE_NAME"
sudo systemctl enable "$SPOOLER_SERVICE_NAME"
# ----
# vim: ts=2:sw=2:et:ai:sts=2

The gitea webhook processorFinally, the script that processes the JSON files does the following:
  1. First, it checks if the repository and branch are right,
  2. Then, it fetches and checks out the commit referenced on the JSON file,
  3. Once the files are updated, compiles the site using hugo with docker compose,
  4. If the compilation succeeds the script renames directories to swap the old version of the site by the new one.
If there is a failure the script aborts but before doing it or if the swap succeeded the system sends an email to the configured address and/or the user that pushed updates to the repository with a log of what happened. The current script is this one:
blogops-webhook.sh
#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
# Values
REPO_REF="refs/heads/main"
REPO_CLONE_URL="https://gitea.mixinet.net/mixinet/blogops.git"
MAIL_PREFIX="[BLOGOPS-WEBHOOK] "
# Address that gets all messages, leave it empty if not wanted
MAIL_TO_ADDR="blogops@mixinet.net"
# If the following variable is set to 'true' the pusher gets mail on failures
MAIL_ERRFILE="false"
# If the following variable is set to 'true' the pusher gets mail on success
MAIL_LOGFILE="false"
# gitea's conf/app.ini value of NO_REPLY_ADDRESS, it is used for email domains
# when the KeepEmailPrivate option is enabled for a user
NO_REPLY_ADDRESS="noreply.example.org"
# Directories
BASE_DIR="/srv/blogops"
PUBLIC_DIR="$BASE_DIR/public"
NGINX_BASE_DIR="$BASE_DIR/nginx"
PUBLIC_HTML_DIR="$NGINX_BASE_DIR/public_html"
WEBHOOK_BASE_DIR="$BASE_DIR/webhook"
WEBHOOK_SPOOL_DIR="$WEBHOOK_BASE_DIR/spool"
WEBHOOK_ACCEPTED="$WEBHOOK_SPOOL_DIR/accepted"
WEBHOOK_DEPLOYED="$WEBHOOK_SPOOL_DIR/deployed"
WEBHOOK_REJECTED="$WEBHOOK_SPOOL_DIR/rejected"
WEBHOOK_TROUBLED="$WEBHOOK_SPOOL_DIR/troubled"
WEBHOOK_LOG_DIR="$WEBHOOK_SPOOL_DIR/log"
# Files
TODAY="$(date +%Y%m%d)"
OUTPUT_BASENAME="$(date +%Y%m%d-%H%M%S.%N)"
WEBHOOK_LOGFILE_PATH="$WEBHOOK_LOG_DIR/$OUTPUT_BASENAME.log"
WEBHOOK_ACCEPTED_JSON="$WEBHOOK_ACCEPTED/$OUTPUT_BASENAME.json"
WEBHOOK_ACCEPTED_LOGF="$WEBHOOK_ACCEPTED/$OUTPUT_BASENAME.log"
WEBHOOK_REJECTED_TODAY="$WEBHOOK_REJECTED/$TODAY"
WEBHOOK_REJECTED_JSON="$WEBHOOK_REJECTED_TODAY/$OUTPUT_BASENAME.json"
WEBHOOK_REJECTED_LOGF="$WEBHOOK_REJECTED_TODAY/$OUTPUT_BASENAME.log"
WEBHOOK_DEPLOYED_TODAY="$WEBHOOK_DEPLOYED/$TODAY"
WEBHOOK_DEPLOYED_JSON="$WEBHOOK_DEPLOYED_TODAY/$OUTPUT_BASENAME.json"
WEBHOOK_DEPLOYED_LOGF="$WEBHOOK_DEPLOYED_TODAY/$OUTPUT_BASENAME.log"
WEBHOOK_TROUBLED_TODAY="$WEBHOOK_TROUBLED/$TODAY"
WEBHOOK_TROUBLED_JSON="$WEBHOOK_TROUBLED_TODAY/$OUTPUT_BASENAME.json"
WEBHOOK_TROUBLED_LOGF="$WEBHOOK_TROUBLED_TODAY/$OUTPUT_BASENAME.log"
# Query to get variables from a gitea webhook json
ENV_VARS_QUERY="$(
  printf "%s" \
    '(.             @sh "gt_ref=\(.ref);"),' \
    '(.             @sh "gt_after=\(.after);"),' \
    '(.repository   @sh "gt_repo_clone_url=\(.clone_url);"),' \
    '(.repository   @sh "gt_repo_name=\(.name);"),' \
    '(.pusher       @sh "gt_pusher_full_name=\(.full_name);"),' \
    '(.pusher       @sh "gt_pusher_email=\(.email);")'
)"
# ---------
# Functions
# ---------
webhook_log()  
  echo "$(date -R) $*" >>"$WEBHOOK_LOGFILE_PATH"
 
webhook_check_directories()  
  for _d in "$WEBHOOK_SPOOL_DIR" "$WEBHOOK_ACCEPTED" "$WEBHOOK_DEPLOYED" \
    "$WEBHOOK_REJECTED" "$WEBHOOK_TROUBLED" "$WEBHOOK_LOG_DIR"; do
    [ -d "$_d" ]   mkdir "$_d"
  done
 
webhook_clean_directories()  
  # Try to remove empty dirs
  for _d in "$WEBHOOK_ACCEPTED" "$WEBHOOK_DEPLOYED" "$WEBHOOK_REJECTED" \
    "$WEBHOOK_TROUBLED" "$WEBHOOK_LOG_DIR" "$WEBHOOK_SPOOL_DIR"; do
    if [ -d "$_d" ]; then
      rmdir "$_d" 2>/dev/null   true
    fi
  done
 
webhook_accept()  
  webhook_log "Accepted: $*"
  mv "$WEBHOOK_JSON_INPUT_FILE" "$WEBHOOK_ACCEPTED_JSON"
  mv "$WEBHOOK_LOGFILE_PATH" "$WEBHOOK_ACCEPTED_LOGF"
  WEBHOOK_LOGFILE_PATH="$WEBHOOK_ACCEPTED_LOGF"
 
webhook_reject()  
  [ -d "$WEBHOOK_REJECTED_TODAY" ]   mkdir "$WEBHOOK_REJECTED_TODAY"
  webhook_log "Rejected: $*"
  if [ -f "$WEBHOOK_JSON_INPUT_FILE" ]; then
    mv "$WEBHOOK_JSON_INPUT_FILE" "$WEBHOOK_REJECTED_JSON"
  fi
  mv "$WEBHOOK_LOGFILE_PATH" "$WEBHOOK_REJECTED_LOGF"
  exit 0
 
webhook_deployed()  
  [ -d "$WEBHOOK_DEPLOYED_TODAY" ]   mkdir "$WEBHOOK_DEPLOYED_TODAY"
  webhook_log "Deployed: $*"
  mv "$WEBHOOK_ACCEPTED_JSON" "$WEBHOOK_DEPLOYED_JSON"
  mv "$WEBHOOK_ACCEPTED_LOGF" "$WEBHOOK_DEPLOYED_LOGF"
  WEBHOOK_LOGFILE_PATH="$WEBHOOK_DEPLOYED_LOGF"
 
webhook_troubled()  
  [ -d "$WEBHOOK_TROUBLED_TODAY" ]   mkdir "$WEBHOOK_TROUBLED_TODAY"
  webhook_log "Troubled: $*"
  mv "$WEBHOOK_ACCEPTED_JSON" "$WEBHOOK_TROUBLED_JSON"
  mv "$WEBHOOK_ACCEPTED_LOGF" "$WEBHOOK_TROUBLED_LOGF"
  WEBHOOK_LOGFILE_PATH="$WEBHOOK_TROUBLED_LOGF"
 
print_mailto()  
  _addr="$1"
  _user_email=""
  # Add the pusher email address unless it is from the domain NO_REPLY_ADDRESS,
  # which should match the value of that variable on the gitea 'app.ini' (it
  # is the domain used for emails when the user hides it).
  # shellcheck disable=SC2154
  if [ -n "$ gt_pusher_email##*@"$ NO_REPLY_ADDRESS " " ] &&
    [ -z "$ gt_pusher_email##*@* " ]; then
    _user_email="\"$gt_pusher_full_name <$gt_pusher_email>\""
  fi
  if [ "$_addr" ] && [ "$_user_email" ]; then
    echo "$_addr,$_user_email"
  elif [ "$_user_email" ]; then
    echo "$_user_email"
  elif [ "$_addr" ]; then
    echo "$_addr"
  fi
 
mail_success()  
  to_addr="$MAIL_TO_ADDR"
  if [ "$MAIL_LOGFILE" = "true" ]; then
    to_addr="$(print_mailto "$to_addr")"
  fi
  if [ "$to_addr" ]; then
    # shellcheck disable=SC2154
    subject="OK - $gt_repo_name updated to commit '$gt_after'"
    mail -s "$ MAIL_PREFIX $ subject " "$to_addr" \
      <"$WEBHOOK_LOGFILE_PATH"
  fi
 
mail_failure()  
  to_addr="$MAIL_TO_ADDR"
  if [ "$MAIL_ERRFILE" = true ]; then
    to_addr="$(print_mailto "$to_addr")"
  fi
  if [ "$to_addr" ]; then
    # shellcheck disable=SC2154
    subject="KO - $gt_repo_name update FAILED for commit '$gt_after'"
    mail -s "$ MAIL_PREFIX $ subject " "$to_addr" \
      <"$WEBHOOK_LOGFILE_PATH"
  fi
 
# ----
# MAIN
# ----
# Check directories
webhook_check_directories
# Go to the base directory
cd "$BASE_DIR"
# Check if the file exists
WEBHOOK_JSON_INPUT_FILE="$1"
if [ ! -f "$WEBHOOK_JSON_INPUT_FILE" ]; then
  webhook_reject "Input arg '$1' is not a file, aborting"
fi
# Parse the file
webhook_log "Processing file '$WEBHOOK_JSON_INPUT_FILE'"
eval "$(jq -r "$ENV_VARS_QUERY" "$WEBHOOK_JSON_INPUT_FILE")"
# Check that the repository clone url is right
# shellcheck disable=SC2154
if [ "$gt_repo_clone_url" != "$REPO_CLONE_URL" ]; then
  webhook_reject "Wrong repository: '$gt_clone_url'"
fi
# Check that the branch is the right one
# shellcheck disable=SC2154
if [ "$gt_ref" != "$REPO_REF" ]; then
  webhook_reject "Wrong repository ref: '$gt_ref'"
fi
# Accept the file
# shellcheck disable=SC2154
webhook_accept "Processing '$gt_repo_name'"
# Update the checkout
ret="0"
git fetch >>"$WEBHOOK_LOGFILE_PATH" 2>&1   ret="$?"
if [ "$ret" -ne "0" ]; then
  webhook_troubled "Repository fetch failed"
  mail_failure
fi
# shellcheck disable=SC2154
git checkout "$gt_after" >>"$WEBHOOK_LOGFILE_PATH" 2>&1   ret="$?"
if [ "$ret" -ne "0" ]; then
  webhook_troubled "Repository checkout failed"
  mail_failure
fi
# Remove the build dir if present
if [ -d "$PUBLIC_DIR" ]; then
  rm -rf "$PUBLIC_DIR"
fi
# Build site
docker compose run hugo -- >>"$WEBHOOK_LOGFILE_PATH" 2>&1   ret="$?"
# go back to the main branch
git switch main && git pull
# Fail if public dir was missing
if [ "$ret" -ne "0" ]   [ ! -d "$PUBLIC_DIR" ]; then
  webhook_troubled "Site build failed"
  mail_failure
fi
# Remove old public_html copies
webhook_log 'Removing old site versions, if present'
find $NGINX_BASE_DIR -mindepth 1 -maxdepth 1 -name 'public_html-*' -type d \
  -exec rm -rf   \; >>"$WEBHOOK_LOGFILE_PATH" 2>&1   ret="$?"
if [ "$ret" -ne "0" ]; then
  webhook_troubled "Removal of old site versions failed"
  mail_failure
fi
# Switch site directory
TS="$(date +%Y%m%d-%H%M%S)"
if [ -d "$PUBLIC_HTML_DIR" ]; then
  webhook_log "Moving '$PUBLIC_HTML_DIR' to '$PUBLIC_HTML_DIR-$TS'"
  mv "$PUBLIC_HTML_DIR" "$PUBLIC_HTML_DIR-$TS" >>"$WEBHOOK_LOGFILE_PATH" 2>&1  
    ret="$?"
fi
if [ "$ret" -eq "0" ]; then
  webhook_log "Moving '$PUBLIC_DIR' to '$PUBLIC_HTML_DIR'"
  mv "$PUBLIC_DIR" "$PUBLIC_HTML_DIR" >>"$WEBHOOK_LOGFILE_PATH" 2>&1  
    ret="$?"
fi
if [ "$ret" -ne "0" ]; then
  webhook_troubled "Site switch failed"
  mail_failure
else
  webhook_deployed "Site deployed successfully"
  mail_success
fi
# ----
# vim: ts=2:sw=2:et:ai:sts=2

6 May 2022

Antoine Beaupr : Wallabako 1.4.0 released

I don't particularly like it when people announce their personal projects on their blog, but I'm making an exception for this one, because it's a little special for me. You see, I have just released Wallabako 1.4.0 (and a quick, mostly irrelevant 1.4.1 hotfix) today. It's the first release of that project in almost 3 years (the previous was 1.3.1, before the pandemic). The other reason I figured I would mention it is that I have almost never talked about Wallabako on this blog at all, so many of my readers probably don't even know I sometimes meddle with in Golang which surprises even me sometimes.

What's Wallabako Wallabako is a weird little program I designed to read articles on my E-book reader. I use it to spend less time on the computer: I save articles in a read-it-later app named Wallabag (hosted by a generous friend), and then Wallabako connects to that app, downloads an EPUB version of the book, and then I can read it on the device directly. When I'm done reading the book, Wallabako notices and sets the article as read in Wallabag. I also set it to delete the book locally, but you can actually configure to keep those books around forever if you feel like it. Wallabako supports syncing read status with the built-in Kobo interface (called "Nickel"), Koreader and Plato. I happen to use Koreader for everything nowadays, but it should work equally well on the others. Wallabako is actually setup to be started by udev when there's a connection change detected by the kernel, which is kind of a gross hack. It's clunky, but actually works and I thought for a while about switching to something else, but it's really the easiest way to go, and that requires the less interaction by the user.

Why I'm (still) using it I wrote Wallabako because I read a lot of articles on the internet. It's actually most of my readings. I read about 10 books a year (which I don't think is much), but I probably read more in terms of time and pages in Wallabag. I haven't actually made the math, but I estimate I spend at least double the time reading articles than I spend reading books. If I wouldn't have Wallabag, I would have hundreds of tabs open in my web browser all the time. So at least that problem is easily solved: throw everything in Wallabag, sort and read later. If I wouldn't have Wallabako however, I would be either spend that time reading on the computer -- which I prefer to spend working on free software or work -- or on my phone -- which is kind of better, but really cramped. I had stopped (and developing) Wallabako for a while, actually, Around 2019, I got tired of always read those technical articles (basically work stuff!) at home. I realized I was just not "reading" (as in books! fiction! fun stuff!) anymore, at least not as much as I wanted. So I tried to make this separation: the ebook reader is for cool book stuff. The rest is work. But because I had the Wallabag Android app on my phone and tablet, I could still read those articles there, which I thought was pretty neat. But that meant that I was constantly looking at my phone, which is something I'm generally trying to avoid, as it sets a bad example for the kids (small and big) around me. Then I realized there was one stray ebook reader lying around at home. I had recently bought a Kobo Aura HD to read books, and I like that device. And it's going to stay locked down to reading books. But there's still that old battered Kobo Glo HD reader lying around, and I figured I could just borrow it to read Wallabag articles.

What is this new release But oh boy that was a lot of work. Wallabako was kind of a mess: it was using the deprecated go dep tool, which lost the battle with go mod. Cross-compilation was broken for older devices, and I had to implement support for Koreader.

go mod So I had to learn go mod. I'm still not sure I got that part right: LSP is yelling at me because it can't find the imports, and I'm generally just "YOLO everythihng" every time I get anywhere close to it. That's not the way to do Go, in general, and not how I like to do it either. But I guess that, given time, I'll figure it out and make it work for me. It certainly works now. I think.

Cross compilation The hard part was different. You see, Nickel uses SQLite to store metadata about books, so Wallabako actually needs to tap into that SQLite database to propagate read status. Originally, I just linked against some sqlite3 library I found lying around. It's basically a wrapper around the C-based SQLite and generally works fine. But that means you actually link your Golang program against a C library. And that's when things get a little nutty. If you would just build Wallabag naively, it would fail when deployed on the Kobo Glo HD. That's because the device runs a really old kernel: the prehistoric Linux kobo 2.6.35.3-850-gbc67621+ #2049 PREEMPT Mon Jan 9 13:33:11 CST 2017 armv7l GNU/Linux. That was built in 2017, but the kernel was actually released in 2010, a whole 5 years before the Glo HD was released, in 2015 which is kind of outrageous. and yes, that is with the latest firmware release. My bet is they just don't upgrade the kernel on those things, as the Glo was probably bought around 2017... In any case, the problem is we are cross-compiling here. And Golang is pretty good about cross-compiling, but because we have C in there, we're actually cross-compiling with "CGO" which is really just Golang with a GCC backend. And that's much, much harder to figure out because you need to pass down flags into GCC and so on. It was a nightmare. That's until I found this outrageous "little" project called modernc.org/sqlite. What that thing does (with a hefty does of dependencies that would make any Debian developer recoil in horror) is to transpile the SQLite C source code to Golang. You read that right: it rewrites SQLite in Go. On the fly. It's nuts. But it works. And you end up with a "pure go" program, and that thing compiles much faster and runs fine on older kernel. I still wasn't sure I wanted to just stick with that forever, so I kept the old sqlite3 code around, behind a compile-time tag. At the top of the nickel_modernc.go file, there's this magic string:
//+build !sqlite3
And at the top of nickel_sqlite3.go file, there's this magic string:
//+build sqlite3
So now, by default, the modernc file gets included, but if I pass --tags sqlite3 to the Go compiler (to go install or whatever), it will actually switch to the other implementation. Pretty neat stuff.

Koreader port The last part was something I was hesitant in doing for a long time, but that turned out to be pretty easy. I have basically switch to using Koreader to read everything. Books, PDF, everything goes through it. I really like that it stores its metadata in sidecar files: I synchronize all my books with Syncthing which means I can carry my read status, annotations and all that stuff without having to think about it. (And yes, I installed Syncthing on my Kobo.) The koreader.go port was less than 80 lines, and I could even make a nice little test suite so that I don't have to redeploy that thing to the ebook reader at every code iteration. I had originally thought I should add some sort of graphical interface in Koreader for Wallabako as well, and had requested that feature upstream. Unfortunately (or fortunately?), they took my idea and just ran with it. Some courageous soul actually wrote a full Wallabag plugin for koreader, in Lua of course. Compared to the Wallabako implementation however, the koreader plugin is much slower, probably because it downloads articles serially instead of concurrently. It is, however, much more usable as the user is given a visible feedback of the various steps. I still had to enable full debugging to diagnose a problem (which was that I shouldn't have a trailing slash, and that some special characters don't work in passwords). It's also better to write the config file with a normal text editor, over SSH or with the Kobo mounted to your computer instead of typing those really long strings over the kobo. There's no sample config file which makes that harder but a workaround is to save the configuration with dummy values and fix them up after. Finally I also found the default setting ("Remotely delete finished articles") really dangerous as it can basically lead to data loss (Wallabag article being deleted!) for an unsuspecting user... So basically, I started working on Wallabag again because the koreader implementation of their Wallabag client was not up to spec for me. It might be good enough for you, but I guess if you like Wallabako, you should thank the koreader folks for their sloppy implementation, as I'm now working again on Wallabako.

Actual release notes Those are the actual release notes for 1.4.0.
Ship a lot of fixes that have accumulated in the 3 years since the last release. Features:
  • add timestamp and git version to build artifacts
  • cleanup and improve debugging output
  • switch to pure go sqlite implementation, which helps
  • update all module dependencies
  • port to wallabago v6
  • support Plato library changes from 0.8.5+
  • support reading koreader progress/read status
  • Allow containerized builds, use gomod and avoid GOPATH hell
  • overhaul Dockerfile
  • switch to go mod
Documentation changes:
  • remove instability warning: this works well enough
  • README: replace branch name master by main in links
  • tweak mention of libreoffice to clarify concern
  • replace "kobo" references by "nickel" where appropriate
  • make a section about related projects
  • mention NickelMenu
  • quick review of the koreader implementation
Bugfixes:
  • handle errors in http request creation
  • Use OutputDir configuration instead of hardcoded wallabako paths
  • do not noisily fail if there's no entry for book in plato
  • regression: properly detect read status again after koreader (or plato?) support was added

How do I use this?
This is amazing. I can't believe someone did something that awesome. I want to cover you with gold and Tesla cars and fresh water.
You're weird please stop. But if you want to use Wallabako, head over to the README file which has installation instructions. It basically uses a hack in Kobo e-readers that will happily overwrite their root filesystem as soon as you drop this file named KoboRoot.tgz in the .kobo directory of your e-reader. Note that there is no uninstall procedure and it messes with the reader's udev configuration (to trigger runs on wifi connect). You'll also need to create a JSON configuration file and configure a client in Wallabag. And if you're looking for Wallabag hosting, Wallabag.it offers a 14-day free trial. You can also, obviously, host it yourself. Which is not the case for Pocket, even years after Mozilla bought the company. All this wouldn't actually be necessary if Pocket was open-source because Nickel actually ships with a Pocket client. Shame on you, Mozilla. But you still make an awesome browser, so keep doing that.

20 April 2022

Russell Coker: Android Without Play

A while ago I was given a few reasonably high-end Android phones to give away. I gave two very nice phones to someone who looks after refugees so a couple of refugee families could make video calls to relatives. The third phone is a Huawei Nova 7i [1] which doesn t have the Google Play Store. The Nova 7i is a ridiculously powerful computer (8G of RAM in a phone!!!) but without the Google Play Store it s not much use to the average phone user. It has the HuaWei App Gallery which isn t as bad as most of the proprietary app stores of small players in the Android world, it has SnapChat, TikTok, Telegram, Alibaba, WeChat, and Grays auction (an app I didn t even know existed) along with many others. It also links to ApkPure (apparently a 3rd party app installer that obtains APK files for major commercial apps) for Facebook among others. The ApkPure thing might be Huawei outsourcing the violation of Facebook terms of service. For the moment I ve decided to only use free software on this phone and use my old phone for non-free stuff (Facebook, LinkedIn, etc). The eventual aim is that I can only carry a phone with free software for normal use and carry a second phone if I m active on LinkedIn or something. My recollection is that when I first got the phone (almost 2 years ago) it didn t have such a range of apps. The first thing to install was f-droid [2] as the app repository. F-droid has a repository of thousands of free software Android apps as well as some apps that are slightly less free which are tagged appropriately. You can install the F-Droid app from the web site. As an aside I had to go to settings and enable force old index format to get the list of packages, I don t know why as other phones had worked without it. Here are the F-Droid apps I installed:
  • Kdeconnect to transfer files to PC. This has some neat features including using the PC keyboard on Android. One downside is that there s no convenient way to kill it. I don t want it hanging around, I want to transfer a file and close it down to minimise exposure.
  • K9 is an Android app for email that I ve used for over a decade now. Previously I ve used it from the Play Store but it s available in F-droid. I used Kdeconnect to transfer the exported configuration from my old phone to my PC and then from my PC to my new phone.
  • I m now using SchildiChat for Matrix as a replacement for Google Hangouts (I previously wrote about how Google is killing Hangouts [3]). One advantage of SchildiChat is that it keeps a notification running 24*7 to reduce the incidence of Android killing it. The process of sending private messages with Matrix seems noticeably slower than Hangouts, while Google will inevitably be faster than a federated system (if only because they buy better hardware than I rent) the difference shouldn t be enough to notice (my Matrix servers might need some work).
  • I used ffupdater to install Firefox. It can also install other browsers that don t publish APK files. One of the options is Ungoogled Chromium which I m not going to use even though I ve found Google Chrome to be a great browser, I think I should go all the way in avoiding Google. There s no description in the app of the differences between the browsers, the ffupdater web page has information about the browsers [4].
  • I use Tusky for Mastodon which is a replacement for Twitter. My Mastodon address is @etbe@mastodon.nzoss.nz. Currently Mastodon needs more users, there are plenty of free servers out there and the New Zealand Open Source Society is just one I have contact with.
  • I have used ConnectBot for ssh connections from Android for over 10 years, previously via the Play Store but it s also in F-droid. To get the hash of a key from a server in the way ConnectBot displays it run ssh-keygen -l -E md5 -f /etc/ssh/ssh_host_ed25519_key.pub .
  • I initially changed Keyboard from MS Swiftkey to the Celia keyboard that came with the phone. But it s spelling correction was terrible, almost never suggesting words with apostrophes when appropriate and also having no apparent option to disable adult words. I m now using OpenBoard which is a port of the Google Android keyboard which works well.
  • I ve just installed primitive ftpd for file transfer, it supports ftp and sftp protocols and is well written.
  • I ve installed the mpv video player which plays FullHD video at high quality using hardware decoding. I don t need to do that sort of thing (the screen is too small to make it worth FullHD video), but it s nice to have.
  • For barcodes and QR codes I m using Binary Eye which seems better than the Play Store one I had used previously.
  • For playing music I ve tried using the Simple Music Player (which is nice for mp3s), but it doesn t play m4a or webm files. Auxio and Music Player Go play mp3 and m4a but not webm. So far the only programs I ve found that can play webm are VLC and MPV, so I m trying out VLC as a music player which it basically does but a program with the same audio features and no menu options about video would be better. Webm is important to me because I have some music videos downloaded from YouTube and webm allows me to put a binary copy of the audio data into an audio file.
Future Plans The current main things I m missing are a calendar, a contact list, and a shared note taking system (like Google Keep). For calendaring and a contact list the CalDAV and CardDAV protocols seem best. The most common implementation on the server side appears to be DAViCal [5]. The Nextcloud system supports CalDAV, CardDAV, web editing of notes and documents (including LibreOffice if you install that plugin) [6]. But it is huge and demands write access to all it s own code (bad for security), and it s not packaged for Debian. Also in my tests it gave me an error 401 when I tried to authenticate to it from the Android Nextcloud client. I ve seen a positive review about Radicale, a simple CalDAV and CardDAV server that doesn t need a database [7]. I prefer the Unix philosophy of keeping things simple with file storage unless there s a real need for anything else. I don t think that anything I ever do with calendaring will require the PostgreSQL database that DAViCal uses. I ll give Radicale a go for CalDAV and CardDAV, but I still need something for shared notes (shopping lists etc). Suggestions welcome. Current Status Lack of a contacts list is a major loss of functionality in a phone. I could store contacts in the phone memory or on the SIM, but I would still have to get all my old contacts in there and also getting something half working reduces motivation for getting it working properly. Lack of a calendar is also a problem, again I could work around that by exporting all my Google calendars as iCal URLs but I d rather get it working correctly. The lack of shared notes may be a harder problem to solve given the failure of Nextcloud. For that I would consider just having the keep.google.com web site always open in Mozilla at least in the short term. At the moment I require two phones, my new Android phone without Google and the old one for my contacts list etc. Hopefully in a week or so I ll have my new phone doing contacts, calendaring, and notes. Then my old phone will just be for proprietary apps which I don t need most of the time and I can leave it at home when I don t need that sort of thing.

4 April 2022

Arturo Borrero Gonz lez: Wikimedia Toolforge and Grid Engine

Logos This post was originally published in the Wikimedia Tech blog, authored by Arturo Borrero Gonzalez. One of the most important and successful products provided by the Wikimedia Cloud Services team at the Wikimedia Foundation is Toolforge, a hosting service commonly known in the industry as Platform as a Service (PaaS). In particular, it is a platform that allows users and developers to run and use a variety of applications with the ultimate goal of helping the Wikimedia mission from the technical side. Toolforge is powered by two different backend engines, Kubernetes and Grid Engine. The two backends have traditionally offered different features for tool developers. But as time moves forward we ve learnt that Kubernetes is the future. Explaining why is the purpose of this blog post: we want to share more information and reasoning behind this mindset. There are a number of reasons that make Grid Engine poorly suitable to remain as execution backend in Toolforge:
  • There has not been a new Grid Engine release (bug fixes, security patches, or otherwise) since 2016. This doesn t feel like a project being actively developed or maintained.
  • The grid has poor support and controls for important aspects such as high availability, fault tolerance and self-recovery.
  • Maintaining a healthy grid requires plenty of manual operations, like manual queue cleanups in case of failures, hand-crafted scripts for pooling/depooling nodes, etc.
  • There is no good or modern monitoring support for the grid, and we need to craft and maintain several monitoring pieces for proper observability, and to be able to do proper maintenance.
  • The grid is also strongly tied to the underlying operating system release version. Migrating from one Debian version to the next is painful (a dedicated blog post about this will follow shortly).
  • The grid imposes a strong dependency on NFS, another old technology. We would like to reduce dependency on NFS overall, and in the future we will explore NFS-free approaches for Toolforge.
  • In general, Grid Engine is old software, old technology, which can be replaced by more modern approaches for providing an equivalent or better service.
As mentioned above, our desire is to cover all our grid-like needs with Kubernetes, a technology which has several benefits:
  • Good high availability, fault tolerance and self-recovery semantics, constructs and facilities.
  • Maintaining a running Kubernetes cluster requires little manual operations.
  • There are good monitoring and observability options for Kubernetes deployments, including seamless integration with industry standards like prometheus.
  • Our current approach to deploying and upgrading Kubernetes is independent of the underlying operating system.
  • While our current Kubernetes deployment uses NFS as a central component, there is support for using other, more modern, approaches for the kind of shared storage needs we have in Toolforge.
  • In general, Kubernetes is a modern technology, with a vibrant and healthy community, that enables new use cases and has enough flexibility to adapt legacy ones.
The relationship between Toolforge and Grid Engine has been interesting over the years. The grid has been used for quite a lot of time, we have plenty of documentation and established good practices. On the other hand, the grid is hard to maintain, imposes a heavy burden on the WMCS team and is a technology we must eventually discontinue. How to accommodate the two realities is a refreshing challenge, one that we hope to tackle together in the near future. A tradeoff exists here, but it is clear to us which option is best. So we will work on deprecating and removing Grid Engine and migrating use cases into Kubernetes. This deprecation, however, will be done with care, as we know our technical community relies on the grid for some import Toolforge tools. And some of these workflows will need some adaptation in order to be fully supported on Kubernetes. Stay tuned for more information on present and next works surrounding the Wikimedia Toolforge service. The next blog post will share more concrete details. This post was originally published in the Wikimedia Tech blog, authored by Arturo Borrero Gonzalez.

1 April 2022

Paul Wise: FLOSS Activities March 2022

Focus This month I didn't have any particular focus. I just worked on issues in my info bubble.

Changes

Issues

Review
  • Spam: reported 3 Debian bug reports and 53 Debian mailing list posts
  • Debian wiki: RecentChanges for the month
  • Debian BTS usertags: changes for the month
  • Debian screenshots:

Administration
  • Debian servers: investigate wiki mail delivery issue, restart backup director
  • Debian wiki: unblock IP addresses, approve accounts

Communication
  • Forward python-plac test failure issue upstream
  • Participate in Debian Project Leader election discussions
  • Respond to queries from Debian users and contributors on the mailing lists and IRC

Sponsors The oci-python-sdk and plac work was sponsored. All other work was done on a volunteer basis.

2 March 2022

Keith Packard: picolibc-testing

Testing Picolibc with the glibc tests Picolibc has a bunch of built-in tests, but more testing is always better, right? I decided to see how hard it would be to run some of the tests provided in the GNU C Library (glibc). Parallel meson build files Similar to how Picolibc uses meson build files to avoid modifying the newlib autotools infrastructure, I decided to take the glibc code and write meson build rules that would compile the tests against Picolibc header files and link against Picolibc libraries. I decided to select a single target for this project so I could focus on getting things building and not worry too much about making it portable. I wanted to pick something that had hardware floating point so that I would have rounding modes and exception support, so I picked the ARM Cortex M7 with hard float ABI:
$ arm-none-eabi-gcc -mcpu=cortex-m7 -mfloat-abi=hard
It should be fairly easy to extend this to other targets, but for now, that's what I've got working. There's a cross-cortex-m7.txt file containing all of the cross compilation details which is used when running meson setup. All of the Picolibc-specific files live in a new picolibc directory so they are isolated from the main glibc code. Pre-loading a pile of hacks Adapt Picolibc to support the Glibc test code required a bunch of random hacks, from providing _unlocked versions of the stdio macros to stubbing out various unsupportable syscalls (like sleep and chdir). Instead of modifying the Glibc code, I created a file called hacks.h which is full of this stuff and used the gcc -include parameter to read that into the compiler before starting compilation on all of the files. Supporting command line parameters The glibc tests all support a range of command line parameters, some of which turned out to be quite useful for this work. Picolibc had limited semihosting support for accessing the command line, but that required modifying applications to go fetch the command line using a special semihosting function. To make this easier, I added a new crt0 variant for picolibc called (oddly) semihost. This extends the existing hosted variant by adding a call to the semihosting library to fetch the current command line and splitting that into words at each space. It doesn't handle any quoting, but it's sufficient for the needs here. Avoiding glibc headers The glibc tests use some glibc-specific extensions to the standard POSIX C library, so I needed to include those in the test builds. Headers for those extensions are mixed in with the rest of the POSIX standard headers, which conflict with the Picolibc versions. To work around this, I stuck stub #include files in the picolibc directory which directly include the appropriate headers for the glibc API extensions. This includes things like argp.h and array_length.h. For other headers which weren't actually needed for picolibc, I created empty files. Adding more POSIX to Picolibc At this point, code was compiling but failing to find various standard POSIX functions which aren't available in Picolibc. That included some syscalls which could be emulated using semihosting, like gettimeofday and getpagesize. It also included some generally useful additions, like replacing ecvtbuf and fcvtbuf with ecvt_r and fcvt_r. The _r variants provide a target buffer size instead of assuming that it was large enough as the Picolibc buf variants did. Which tests are working? So far, I've got some of the tests in malloc, math, misc and stdio-common running. There are a lot of tests in the malloc directory which cover glibc API extensions or require POSIX syscalls not supported by semihosting. I think I've added all of the tests which should be supported. For the math tests, I'm testing the standard POSIX math APIs in both float and double forms, except for the Bessel and Gamma functions. Picolibc's versions of those are so bad that they violate some pretty basic assumptions about error bounds built into the glibc test code. Until Picolibc gets better versions of these functions, we'll have to skip testing them this way. In the misc directory, I've only added tests for ecvt, fcvt, gcvt, dirname and hsearch. I don't think there are any other tests there which should work. Finally, for stdio-common, almost all of the tests expect a fully functioning file system, which semihosting really can't support. As a result, we're only able to run the printf, scanf and some of the sprintf tests. All in all, we're running 78 of the glibc test programs, which is a small fraction of the total tests, but I think it's the bulk of the tests which cover APIs that don't depend too much on the underlying POSIX operating system. Bugs found and fixed in Picolibc This exercise has resulted in 17 fixes in Picolibc, which can be classified as:
  1. Math functions taking sNaN and not raising FE_INVALID and returning qNaN. Almost any operation on an sNaN value is supposed to signal an invalid operand and replace that with a qNaN so that further processing doesn't raise another exception. This was fairly easy to fix, just need to use return x + x; instead of return x;.
  2. Math functions failing to set errno. I'd recently restructured the math library to get rid of the separate IEEE version of the functions which didn't set errno and missed a couple of cases that needed to use the errno-setting helper functions.
  3. Corner cases in string/float conversion, including the need to perform round-to-even for '%a' conversions in printf and supporting negative decimal values for fcvt. This particular exercise led to replacing the ecvtbuf and fcvtbuf APIs with glibc's ecvt_r and fcvt_r versions as those pass explicit buffer lengths, making overflow prevention far more reliable.
  4. A bunch of malloc entry points were not handling failure correctly; allocation values close to the maximum possible size caused numerous numeric wrapping errors with the usual consequences (allocations "succeed", but return a far smaller buffer than requested). Also, realloc was failing to check the return value from malloc before copying the old data, which really isn't a good idea.
  5. Tinystdio's POSIX support code was returning an error instead of EOF at end of file.
  6. Error bounds for the Picolibc math library aren't great; I had to generate Picolibc-specific ulps files. Most functions are between 0 and 3 ulps, but for some reason, the float version of erfc (ercf) has errors as large as 64 ulps. That needs investigation.
Tests added to Picolibc With all of the fixes applied to Picolibc, I added some tests to verify them without relying on running the glibc tests, that includes sNaN vs qNaN tests for math functions, testing fopen and mktemp, checking the printf %a rounding support and adding a ecvt/fcvt tests. I also discovered that the github-based CI system was compiling but not testing when using clang with a riscv target, so that got added in. Where's the source code? The Picolibc changes are sitting on the glibc-testing branch. I'll merge them once the current CI pass finishes. The hacked-up Glibc bits are in a glibc mirror at github in the picolibc project on the picolibc-testing branch. It would be interesting to know what additional tests should be usable in this environment. And, perhaps, finding a way to use this for picolibc CI testing in the future. Concluding thoughts Overall, I'm pretty pleased with these results. The bugs in malloc are fairly serious and could easily result in trouble, but the remaining issues are mostly minor and shouldn't have a big impact on applications using Picolibc. I'll get the changes merged and start thinking about doing another Picolibc release.

Next.

Previous.