Search Results: "cts"

27 September 2022

Fran ois Marier: Upgrading from chan_sip to res_pjsip in Asterisk 18

After upgrading to Ubuntu Jammy and Asterisk 18.10, I saw the following messages in my logs:
WARNING[360166]: loader.c:2487 in load_modules: Module 'chan_sip' has been loaded but was deprecated in Asterisk version 17 and will be removed in Asterisk version 21.
WARNING[360174]: chan_sip.c:35468 in deprecation_notice: chan_sip has no official maintainer and is deprecated.  Migration to
WARNING[360174]: chan_sip.c:35469 in deprecation_notice: chan_pjsip is recommended.  See guides at the Asterisk Wiki:
WARNING[360174]: chan_sip.c:35470 in deprecation_notice: https://wiki.asterisk.org/wiki/display/AST/Migrating+from+chan_sip+to+res_pjsip
WARNING[360174]: chan_sip.c:35471 in deprecation_notice: https://wiki.asterisk.org/wiki/display/AST/Configuring+res_pjsip
and so I decided it was time to stop postponing the overdue migration of my working setup from chan_sip to res_pjsip. It turns out that it was not as painful as I expected, though the conversion script bundled with Asterisk didn't work for me out of the box.

Debugging Before you start, one very important thing to note is that the SIP debug information you used to see when running this in the asterisk console (asterisk -r):
sip set debug on
now lives behind this command:
pjsip set logger on

SIP phones The first thing I migrated was the config for my two SIP phones (Snom 300 and Snom D715). The original config for them in sip.conf was:
[2000]
; Snom 300
type=friend
qualify=yes
secret=password123
encryption=no
context=full
host=dynamic
nat=no
directmedia=no
mailbox=10@internal
vmexten=707
dtmfmode=rfc2833
call-limit=2
disallow=all
allow=g722
allow=ulaw
[2001]
; Snom D715
type=friend
qualify=yes
secret=password456
encryption=no
context=full
host=dynamic
nat=no
directmedia=yes
mailbox=10@internal
vmexten=707
dtmfmode=rfc2833
call-limit=2
disallow=all
allow=g722
allow=ulaw
and that became the following in pjsip.conf:
[transport-udp]
type = transport
protocol = udp
bind = 0.0.0.0
external_media_address = myasterisk.dyn.example.com
external_signaling_address = myasterisk.dyn.example.com
local_net = 192.168.0.0/255.255.0.0
[2000]
type = aor
max_contacts = 1
[2000]
type = auth
username = 2000
password = password123
[2000]
type = endpoint
context = full
dtmf_mode = rfc4733
disallow = all
allow = g722
allow = ulaw
direct_media = no
mailboxes = 10@internal
auth = 2000
outbound_auth = 2000
aors = 2000
[2001]
type = aor
max_contacts = 1
[2001]
type = auth
username = 2001
password = password456
[2001]
type = endpoint
context = full
dtmf_mode = rfc4733
disallow = all
allow = g722
allow = ulaw
direct_media = yes
mailboxes = 10@internal
auth = 2001
outbound_auth = 2001
aors = 2001
The different direct_media line between the two phones has to do with how they each connect to my Asterisk server and whether or not they have access to the Internet.

Internal calls For some reason, my internal calls (from one SIP phone to the other) didn't work when using "aliases". I fixed it by changing this blurb in extensions.conf from:
[speeddial]
exten => 1000,1,Dial(SIP/2000,20)
exten => 1001,1,Dial(SIP/2001,20)
to:
[speeddial]
exten => 1000,1,Dial($ PJSIP_DIAL_CONTACTS(2000) ,20)
exten => 1001,1,Dial($ PJSIP_DIAL_CONTACTS(2001) ,20)
I have not yet dug into what this changes or why it's necessary and so feel free to leave a comment if you know more here.

PSTN trunk Once I had the internal phones working, I moved to making and receiving phone calls over the PSTN, for which I use VoIP.ms with encryption. I had to change the following in my sip.conf:
[general]
register => tls://555123_myasterisk:password789@vancouver2.voip.ms
externhost=myasterisk.dyn.example.com
localnet=192.168.0.0/255.255.0.0
tcpenable=yes
tlsenable=yes
tlscertfile=/etc/asterisk/asterisk.cert
tlsprivatekey=/etc/asterisk/asterisk.key
tlscapath=/etc/ssl/certs/
[voipms]
type=peer
host=vancouver2.voip.ms
secret=password789
defaultuser=555123_myasterisk
context=from-voipms
disallow=all
allow=ulaw
allow=g729
insecure=port,invite
canreinvite=no
trustrpid=yes
sendrpid=yes
transport=tls
encryption=yes
to the following in pjsip.conf:
[transport-tls]
type = transport
protocol = tls
bind = 0.0.0.0
external_media_address = myasterisk.dyn.example.com
external_signaling_address = myasterisk.dyn.example.com
local_net = 192.168.0.0/255.255.0.0
cert_file = /etc/asterisk/asterisk.cert
priv_key_file = /etc/asterisk/asterisk.key
ca_list_path = /etc/ssl/certs/
method = tlsv1_2
[voipms]
type = registration
transport = transport-tls
outbound_auth = voipms
client_uri = sip:555123_myasterisk@vancouver2.voip.ms
server_uri = sip:vancouver2.voip.ms
[voipms]
type = auth
password = password789
username = 555123_myasterisk
[voipms]
type = aor
contact = sip:555123_myasterisk@vancouver2.voip.ms
[voipms]
type = identify
endpoint = voipms
match = vancouver2.voip.ms
[voipms]
type = endpoint
context = from-voipms
disallow = all
allow = ulaw
allow = g729
from_user = 555123_myasterisk
trust_id_inbound = yes
media_encryption = sdes
auth = voipms
outbound_auth = voipms
aors = voipms
rtp_symmetric = yes
rewrite_contact = yes
send_rpid = yes
timers = no
The TLS method line is needed since the default in Debian OpenSSL is too strict. The timers line is to prevent outbound calls from getting dropped after 15 minutes. Finally, I changed the Dial() lines in these extensions.conf blurbs from:
[from-voipms]
exten => 5551231000,1,Goto(2000,1)
exten => 2000,1,Dial(SIP/2000&SIP/2001,20)
exten => 2000,n,Goto(in2000-$ DIALSTATUS ,1)
exten => 2000,n,Hangup
exten => in2000-BUSY,1,VoiceMail(10@internal,su)
exten => in2000-BUSY,n,Hangup
exten => in2000-CONGESTION,1,VoiceMail(10@internal,su)
exten => in2000-CONGESTION,n,Hangup
exten => in2000-CHANUNAVAIL,1,VoiceMail(10@internal,su)
exten => in2000-CHANUNAVAIL,n,Hangup
exten => in2000-NOANSWER,1,VoiceMail(10@internal,su)
exten => in2000-NOANSWER,n,Hangup
exten => _in2000-.,1,Hangup(16)
[pstn-voipms]
exten => _1NXXNXXXXXX,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _1NXXNXXXXXX,n,Dial(SIP/voipms/$ EXTEN )
exten => _1NXXNXXXXXX,n,Hangup()
exten => _NXXNXXXXXX,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _NXXNXXXXXX,n,Dial(SIP/voipms/1$ EXTEN )
exten => _NXXNXXXXXX,n,Hangup()
exten => _011X.,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _011X.,n,Authenticate(1234)
exten => _011X.,n,Dial(SIP/voipms/$ EXTEN )
exten => _011X.,n,Hangup()
exten => _00X.,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _00X.,n,Authenticate(1234)
exten => _00X.,n,Dial(SIP/voipms/$ EXTEN )
exten => _00X.,n,Hangup()
to:
[from-voipms]
exten => 5551231000,1,Goto(2000,1)
exten => 2000,1,Dial(PJSIP/2000&PJSIP/2001,20)
exten => 2000,n,Goto(in2000-$ DIALSTATUS ,1)
exten => 2000,n,Hangup
exten => in2000-BUSY,1,VoiceMail(10@internal,su)
exten => in2000-BUSY,n,Hangup
exten => in2000-CONGESTION,1,VoiceMail(10@internal,su)
exten => in2000-CONGESTION,n,Hangup
exten => in2000-CHANUNAVAIL,1,VoiceMail(10@internal,su)
exten => in2000-CHANUNAVAIL,n,Hangup
exten => in2000-NOANSWER,1,VoiceMail(10@internal,su)
exten => in2000-NOANSWER,n,Hangup
exten => _in2000-.,1,Hangup(16)
[pstn-voipms]
exten => _1NXXNXXXXXX,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _1NXXNXXXXXX,n,Dial(PJSIP/$ EXTEN @voipms)
exten => _1NXXNXXXXXX,n,Hangup()
exten => _NXXNXXXXXX,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _NXXNXXXXXX,n,Dial(PJSIP/1$ EXTEN @voipms)
exten => _NXXNXXXXXX,n,Hangup()
exten => _011X.,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _011X.,n,Authenticate(1234)
exten => _011X.,n,Dial(PJSIP/$ EXTEN @voipms)
exten => _011X.,n,Hangup()
exten => _00X.,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _00X.,n,Authenticate(1234)
exten => _00X.,n,Dial(PJSIP/$ EXTEN @voipms)
exten => _00X.,n,Hangup()
Note that it's not just replacing SIP/ with PJSIP/, but it was also necessary to use a format supported by pjsip for the channel since SIP/trunkname/extension isn't supported by pjsip.

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.

Shirish Agarwal: Rama II, Arthur C. Clarke, Aliens

Rama II This would be more of a short post about the current book I am reading. Now people who have seen Arrival would probably be more at home. People who have also seen Avatar would also be familiar to the theme or concept I am sharing about. Now before I go into detail, it seems that Arthur C. Clarke wanted to use a powerful god or mythological character for the name and that is somehow the RAMA series started. Now the first book in the series explores an extraterrestrial spaceship that earth people see/connect with. The spaceship is going somewhere and is doing an Earth flyby so humans don t have much time to explore the spaceship and it is difficult to figure out how the spaceship worked. The spaceship is around 40 km. long. They don t meet any living Ramans but mostly automated systems and something called biots. As I m still reading it, I can t really say what happens next. Although in Rama or Rama I, the powers that be want to destroy it while in the end last they don t. Whether they could have destroyed it or not would be whole another argument. What people need to realize is that the book is a giant What IF scenario.

Aliens If there were any intelligent life in the Universe, I don t think they will take the pain of visiting Earth. And the reasons are far more mundane than anything else. Look at how we treat each other. One of the largest democracies on Earth, The U.S. has been so divided. While the progressives have made some good policies, the Republicans are into political stunts, consider the political stunt of sending Refugees to Martha s Vineyard. The ex-president also made a statement that he can declassify anything just by thinking about it. Now understand this, a refugee is a legal migrant whose papers would be looked into by the American Govt. and till the time he/she/their application is approved or declined they can work, have a house, or do whatever to support themselves. There is a huge difference between having refugee status and being an undocumented migrant. And it isn t as if the Republicans don t know this, they did it because they thought they will be able to get away with it. Both the above episodes don t throw us in a good light. If we treat others like the above, how can we expect to be treated? And refugees always have a hard time, not just in the U.S, , the UK you name it. The UK just some months ago announced a controversial deal where they will send Refugees to Rwanda while their refugee application is accepted or denied, most of them would be denied. The Indian Government is more of the same. A friend, a casual acquaintance Nishant Shah shared the same issues as I had shared a few weeks back even though he s an NRI. So, it seems we are incapable of helping ourselves as well as helping others. On top of it, we have the temerity of using the word alien for them. Now, just for a moment, imagine you are an intelligent life form. An intelligent life-form that could coax energy from the stars, why would you come to Earth, where the people at large have already destroyed more than half of the atmosphere and still arguing about it with the other half. On top of it, we see a list of authoritarian figures like Putin, Xi Jinping whose whole idea is to hold on to power for as long as they can, damn the consequences. Mr. Modi is no different, he is the dumbest of the lot and that s saying something. Most of the projects made by him are in disarray, Pune Metro, my city giving an example. And this is when Pune was the first applicant to apply for a Metro. Just like the UK, India too has tanked the economy under his guidance. Every time they come closer to target dates, the targets are put far into the future, for e.g. now they have said 2040 for a good economy. And just like in other countries, he has some following even though he has a record of failure in every sector of the economy, education, and defense, the list is endless. There isn t a single accomplishment by him other than screwing with other religions. Most of my countrymen also don t really care or have a bother to see how the economy grows and how exports play a crucial part otherwise they would be more alert. Also, just like the UK, India too gave tax cuts to the wealthy, most people don t understand how economies function and the PM doesn t care. The media too is subservient and because nobody asks the questions, nobody seems to be accountable :(.

Religion There is another aspect that also has been to the fore, just like in medieval times, I see a great fervor for religion happening here, especially since the pandemic and people are much more insecure than ever before. Before, I used to think that insecurity and religious appeal only happen in the uneducated, and I was wrong. I have friends who are highly educated and yet still are blinded by religion. In many such cases or situations, I find their faith to be a sham. If you have faith, then there shouldn t be any room for doubt or insecurity. And if you are not in doubt or insecure, you won t need to talk about your religion. The difference between the two is that a person is satiated himself/herself/themselves with thirst and hunger. That person would be in a relaxed mode while the other person would continue to create drama as there is no peace in their heart. Another fact is none of the major religions, whether it is Christianity, Islam, Buddhism or even Hinduism has allowed for the existence of extraterrestrials. We have already labeled them as aliens even before meeting them & just our imagination. And more often than not, we end up killing them. There are and have been scores of movies that have explored the idea. Independence day, Aliens, Arrival, the list goes on and on. And because our religions have never thought about the idea of ET s and how they will affect us, if ET s do come, all the religions and religious practices would panic and die. That is the possibility why even the 1947 Roswell Incident has been covered up . If the above was not enough, the bombing of Hiroshima and Nagasaki by the Americans would always be a black mark against humanity. From the alien perspective, if you look at the technology that they have vis-a-vis what we have, they will probably think of us as spoilt babies and they wouldn t be wrong. Spoilt babies with nuclear weapons are not exactly a healthy mix

Earth To add to our fragile ego, we didn t even leave earth even though we have made sure we exploit it as much as we can. We even made the anthropocentric or homocentric view that makes man the apex animal and to top it we have this weird idea that extraterrestrials come here or will invade for water. A species that knows how to get energy out of stars but cannot make a little of H2O. The idea belies logic and again has been done to death. Why we as humans are so insecure even though we have been given so much I fail to understand. I have shared on numerous times the Kardeshev Scale on this blog itself. The above are some of the reasons why Arthur C. Clarke s works are so controversial and this is when I haven t even read the whole book. It forces us to ask questions that we normally would never think about. And I have to repeat that when these books were published for the first time, they were new ideas. All the movies, from Stanley Kubrick s 2001: Space Odyssey, Aliens, Arrival, and Avatar, somewhere or the other reference some aspect of this work. It is highly possible that I may read and re-read the book couple of times before beginning the next one. There is also quite a bit of human drama, but then that is to be expected. I have to admit I did have some nice dreams after reading just the first few pages, imagining being given the opportunity to experience an Extraterrestrial spaceship that is beyond our wildest dreams. While the Governments may try to cover up or something, the ones who get to experience that spacecraft would be unimaginable. And if they were able to share the pictures or a Livestream, it would be nothing short of amazing. For those who want to, there is a lot going on with the New James Webb Telescope. I am sure it would give rise to more questions than answers.

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.

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19 September 2022

Antoine Beaupr : Looking at Wayland terminal emulators

Back in 2018, I made a two part series about terminal emulators that was actually pretty painful to write. So I'm not going to retry this here, not at all. Especially since I'm not submitting this to the excellent LWN editors so I can get away with not being very good at writing. Phew. Still, it seems my future self will thank me for collecting my thoughts on the terminal emulators I have found out about since I wrote that article. Back then, Wayland was not quite at the level where it is now, being the default in Fedora (2016), Debian (2019), RedHat (2019), and Ubuntu (2021). Also, a bunch of folks thought they would solve everything by using OpenGL for rendering. Let's see how things stack up.

Recap In the previous article, I touched on those projects:
Terminal Changes since review
Alacritty releases! scrollback, better latency, URL launcher, clipboard support, still not in Debian, but close
GNOME Terminal not much? couldn't find a changelog
Konsole outdated changelog, color, image previews, clickable files, multi-input, SSH plugin, sixel images
mlterm long changelog but: supports console mode (like GNU screen?!), Wayland support through libvte, sixel graphics, zmodem, mosh (!)
pterm changes: Wayland support
st unparseable changelog, suggests scroll(1) or scrollback.patch for scrollback now
Terminator moved to GitHub, Python 3 support, not being dead
urxvt no significant changes, a single release, still in CVS!
Xfce Terminal hard to parse changelog, presumably some improvements to paste safety?
xterm notoriously hard to parse changelog, improvements to paste safety (disallowedPasteControls), fonts, clipboard improvements?
After writing those articles, bizarrely, I was still using rxvt even though it did not come up as shiny as I would have liked. The colors problems were especially irritating. I briefly played around with Konsole and xterm, and eventually switched to XTerm as my default x-terminal-emulator "alternative" in my Debian system, while writing this. I quickly noticed why I had stopped using it: clickable links are a huge limitation. I ended up adding keybindings to open URLs in a command. There's another keybinding to dump the history into a command. Neither are as satisfactory as just clicking a damn link.

Requirements Figuring out my requirements is actually a pretty hard thing to do. In my last reviews, I just tried a bunch of stuff and collected everything, but a lot of things (like tab support) I don't actually care about. So here's a set of things I actually do care about:
  • latency
  • resource usage
  • proper clipboard support, that is:
    • mouse selection and middle button uses PRIMARY
    • control-shift-c and control-shift-v for CLIPBOARD
  • true color support
  • no known security issues
  • active project
  • paste protection
  • clickable URLs
  • scrollback
  • font resize
  • non-destructive text-wrapping (ie. resizing a window doesn't drop scrollback history)
  • proper unicode support (at least latin-1, ideally "everything")
  • good emoji support (at least showing them, ideally "nicely"), which involves font fallback
Latency is particularly something I wonder about in Wayland. Kitty seem to have been pretty dilligent at doing latency tests, claiming 35ms with a hardware-based latency tester and 7ms with typometer, but it's unclear how those would come up in Wayland because, as far as I know, typometer does not support Wayland.

Candidates Those are the projects I am considering.
  • darktile - GPU rendering, Unicode support, themable, ligatures (optional), Sixel, window transparency, clickable URLs, true color support, not in Debian
  • foot - Wayland only, daemon-mode, sixel images, scrollback search, true color, font resize, URLs not clickable, but keyboard-driven selection, proper clipboard support, in Debian
  • havoc - minimal, scrollback, configurable keybindings, not in Debian
  • sakura - libvte, Wayland support, tabs, no menu bar, original libvte gangster, dynamic font size, probably supports Wayland, in Debian
  • termonad - Haskell? in Debian
  • wez - Rust, Wayland, multiplexer, ligatures, scrollback search, clipboard support, bracketed paste, panes, tabs, serial port support, Sixel, Kitty, iTerm graphics, built-in SSH client (!?), not in Debian
  • XTerm - status quo, no Wayland port obviously
  • zutty: OpenGL rendering, true color, clipboard support, small codebase, no Wayland support, crashes on bremner's, in Debian

Candidates not considered

Alacritty I would really, really like to use Alacritty, but it's still not packaged in Debian, and they haven't fully addressed the latency issues although, to be fair, maybe it's just an impossible task. Once it's packaged in Debian, maybe I'll reconsider.

Kitty Kitty is a "fast, feature-rich, GPU based", with ligatures, emojis, hyperlinks, pluggable, scriptable, tabs, layouts, history, file transfer over SSH, its own graphics system, and probably much more I'm forgetting. It's packaged in Debian. So I immediately got two people commenting (on IRC) that they use Kitty and are pretty happy with it. I've been hesitant in directly talking about Kitty publicly, but since it's likely there will be a pile-up of similar comments, I'll just say why it's not the first in my list, even if it might, considering it's packaged in Debian and otherwise checks all the boxes. I don't trust the Kitty code. Kitty was written by the same author as Calibre, which has a horrible security history and generally really messy source code. I have tried to do LTS work on Calibre, and have mostly given up on the idea of making that program secure in any way. See calibre for the details on that. Now it's possible Kitty is different: it's quite likely the author has gotten some experience writing (and maintaining for so long!) Calibre over the years. But I would be more optimistic if the author's reaction to the security issues were more open and proactive. I've also seen the same reaction play out on Kitty's side of things. As anyone who worked on writing or playing with non-XTerm terminal emulators, it's quite a struggle to make something (bug-for-bug) compatible with everything out there. And Kitty is in that uncomfortable place right now where it diverges from the canon and needs its own entry in the ncurses database. I don't remember the specifics, but the author also managed to get into fights with those people as well, which I don't feel is reassuring for the project going forward. If security and compatibility wasn't such big of a deal for me, I wouldn't mind so much, but I'll need a lot of convincing before I consider Kitty more seriously at this point.

Next steps It seems like Arch Linux defaults to foot in Sway, and I keep seeing it everywhere, so it is probably my next thing to try, if/when I switch to Wayland. One major problem with foot is that it's yet another terminfo entry. They did make it into ncurses (patch 2021-07-31) but only after Debian bullseye stable was released. So expect some weird compatibility issues when connecting to any other system that is older or the same as stable (!). One question mark with all Wayland terminals, and Foot in particular, is how much latency they introduce in the rendering pipeline. The foot performance and benchmarks look excellent, but do not include latency benchmarks.

No conclusion So I guess that's all I've got so far, I may try alacritty if it hits Debian, or foot if I switch to Wayland, but for now I'm hacking in xterm still. Happy to hear ideas in the comments. Stay tuned for more happy days.

Matthew Garrett: Bring Your Own Disaster

After my last post, someone suggested that having employers be able to restrict keys to machines they control is a bad thing. So here's why I think Bring Your Own Device (BYOD) scenarios are bad not only for employers, but also for users.

There's obvious mutual appeal to having developers use their own hardware rather than rely on employer-provided hardware. The user gets to use hardware they're familiar with, and which matches their ergonomic desires. The employer gets to save on the money required to buy new hardware for the employee. From this perspective, there's a clear win-win outcome.

But once you start thinking about security, it gets more complicated. If I, as an employer, want to ensure that any systems that can access my resources meet a certain security baseline (eg, I don't want my developers using unpatched Windows ME), I need some of my own software installed on there. And that software doesn't magically go away when the user is doing their own thing. If a user lends their machine to their partner, is the partner fully informed about what level of access I have? Are they going to feel that their privacy has been violated if they find out afterwards?

But it's not just about monitoring. If an employee's machine is compromised and the compromise is detected, what happens next? If the employer owns the system then it's easy - you pick up the device for forensic analysis and give the employee a new machine to use while that's going on. If the employee owns the system, they're probably not going to be super enthusiastic about handing over a machine that also contains a bunch of their personal data. In much of the world the law is probably on their side, and even if it isn't then telling the employee that they have a choice between handing over their laptop or getting fired probably isn't going to end well.

But obviously this is all predicated on the idea that an employer needs visibility into what's happening on systems that have access to their systems, or which are used to develop code that they'll be deploying. And I think it's fair to say that not everyone needs that! But if you hold any sort of personal data (including passwords) for any external users, I really do think you need to protect against compromised employee machines, and that does mean having some degree of insight into what's happening on those machines. If you don't want to deal with the complicated consequences of allowing employees to use their own hardware, it's rational to ensure that only employer-owned hardware can be used.

But what about the employers that don't currently need that? If there's no plausible future where you'll host user data, or where you'll sell products to others who'll host user data, then sure! But if that might happen in future (even if it doesn't right now), what's your transition plan? How are you going to deal with employees who are happily using their personal systems right now? At what point are you going to buy new laptops for everyone? BYOD might work for you now, but will it always?

And if your employer insists on employees using their own hardware, those employees should ask what happens in the event of a security breach. Whose responsibility is it to ensure that hardware is kept up to date? Is there an expectation that security can insist on the hardware being handed over for investigation? What information about the employee's use of their own hardware is going to be logged, who has access to those logs, and how long are those logs going to be kept for? If those questions can't be answered in a reasonable way, it's a huge red flag. You shouldn't have to give up your privacy and (potentially) your hardware for a job.

Using technical mechanisms to ensure that employees only use employer-provided hardware is understandably icky, but it's something that allows employers to impose appropriate security policies without violating employee privacy.

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17 September 2022

Russ Allbery: Effective altruism and the control trap

William MacAskill has been on a book tour for What We Owe to the Future, which has put effective altruism back in the news. That plus the decision by GiveWell to remove GiveDirectly from their top charity list got me thinking about charity again. I think effective altruism, by embracing long-termism, is falling into an ethical trap, and I'm going to start heavily discounting their recommendations for donations. Background Some background first for people who have no idea what I'm talking about. Effective altruism is the idea that we should hold charities accountable for effectiveness. It's not sufficient to have an appealing mission. A charity should demonstrate that the money they spend accomplishes the goals they claimed it would. There is a lot of debate around defining "effective," but as a basic principle, this is sound. Mainstream charity evaluators such as Charity Navigator measure overhead and (arguable) waste, but they don't ask whether the on-the-ground work of the charity has a positive effect proportional to the resources it's expending. This is a good question to ask. GiveWell is a charity research organization that directs money for donors based on effective altruism principles. It's one of the central organizations in effective altruism. GiveDirectly is a charity that directly transfers money from donors to poor people. It doesn't attempt to build infrastructure, buy specific things, or fund programs. It identifies poor people and gives them cash with no strings attached. Long-termism is part of the debate over what "effectiveness" means. It says we should value impact on future generations more highly than we tend to do. (In other words, we should have a much smaller future discount rate.) A sloppy but intuitive expression of long-termism is that (hopefully) there will be far more humans living in the future than are living today, and therefore a "greatest good for the greatest number" moral philosophy argues that we should invest significant resources into making the long-term future brighter. This has obvious appeal to those of us who are concerned about the long-term impacts of climate change, for example. There is a lot of overlap between the communities of effective altruism, long-termism, and "rationalism." One way this becomes apparent is that all three communities have a tendency to obsess over the risks of sentient AI taking over the world. I'm going to come back to that. Psychology of control GiveWell, early on, discovered that GiveDirectly was measurably more effective than most charities. Giving money directly to poor people without telling them how to spend it produced more benefits for those people and their surrounding society than nearly all international aid charities. GiveDirectly then became the baseline for GiveWell's evaluations, and GiveWell started looking for ways to be more effective than that. There is some logic to thinking more effectiveness is possible. Some problems are poorly addressed by markets and too large for individual spending. Health care infrastructure is an obvious example. That said, there's also a psychological reason to look for other charities. Part of the appeal of charity is picking a cause that supports your values (whether that be raw effectiveness or something else). Your opinions and expertise are valued alongside your money. In some cases, this may be objectively true. But in all cases, it's more flattering to the ego than giving poor people cash. At that point, the argument was over how to address immediate and objectively measurable human problems. The innovation of effective altruism is to tie charitable giving to a research feedback cycle. You measure the world, see if it is improving, and adjust your funding accordingly. Impact is measured by its effects on actual people. Effective altruism was somewhat suspicious of talking directly to individuals and preferred "objective" statistical measures, but the point was to remain in contact with physical reality. Enter long-termism: what if you could get more value for your money by addressing problems that would affect vast numbers of future people, instead of the smaller number of people who happen to be alive today? Rather than looking at the merits of that argument, look at its psychology. Real people are messy. They do things you don't approve of. They have opinions that don't fit your models. They're hard to "objectively" measure. But people who haven't been born yet are much tidier. They're comfortably theoretical; instead of having to go to a strange place with unfamiliar food and languages to talk to people who aren't like you, you can think hard about future trends in the comfort of your home. You control how your theoretical future people are defined, so the results of your analysis will align with your philosophical and ideological beliefs. Problems affecting future humans are still extrapolations of problems visible today in the world, though. They're constrained by observations of real human societies, despite the layer of projection and extrapolation. We can do better: what if the most serious problem facing humanity is the possible future development of rogue AI? Here's a problem that no one can observe or measure because it's never happened. It is purely theoretical, and thus under the control of the smart philosopher or rich western donor. We don't know if a rogue AI is possible, what it would be like, how one might arise, or what we could do about it, but we can convince ourselves that all those things can be calculated with some probability bar through the power of pure logic. Now we have escaped the uncomfortable psychological tension of effective altruism and returned to the familiar world in which the rich donor can define both the problem and the solution. Effectiveness is once again what we say it is. William MacAskill, one of the originators of effective altruism, now constantly talks about the threat of rogue AI. In a way, it's quite sad. Where to give money? The mindset of long-termism is bad for the human brain. It whispers to you that you're smarter than other people, that you know what's really important, and that you should retain control of more resources because you'll spend them more wisely than others. It's the opposite of intellectual humility. A government funding agency should take some risks on theoretical solutions to real problems, and maybe a few on theoretical solutions to theoretical problems (although an order of magnitude less). I don't think this is a useful way for an individual donor to think. So, if I think effective altruism is abandoning the one good idea it had and turning back into psychological support for the egos of philosophers and rich donors, where does this leave my charitable donations? To their credit, GiveWell so far seems uninterested in shifting from concrete to theoretical problems. However, they believe they can do better by picking projects than giving people money, and they're committing to that by dropping GiveDirectly (while still praising them). They may be right. But I'm increasingly suspicious of the level of control donors want to retain. It's too easy to trick oneself into thinking you know better than the people directly affected. I have two goals when I donate money. One is to make the world a better, kinder place. The other is to redistribute wealth. I have more of something than I need, and it should go to someone who does need it. The net effect should be to make the world fairer and more equal. The first goal argues for effective altruism principles: where can I give money to have the most impact on making the world better? The second goal argues for giving across an inequality gradient. I should find the people who are struggling the most and transfer as many resources to them as I can. This is Peter Singer's classic argument for giving money to the global poor. I think one can sometimes do better than transferring money, but doing so requires a deep understanding of the infrastructure and economies of scale that are being used as leverage. The more distant one is from a society, the more dubious I think one should be of one's ability to evaluate that, and the more wary one should be of retaining any control over how resources are used. Therefore, I'm pulling my recurring donation to GiveWell. Half of it is going to go to GiveDirectly, because I think it is an effective way of redistributing wealth while giving up control. The other half is going to my local foodbank, because they have a straightforward analysis of how they can take advantage of economy of scale, and because I have more tools available (such as local news) to understand what problem they're solving and if they're doing so effectively. I don't know that those are the best choices. There are a lot of good ones. But I do feel strongly that the best charity comes from embracing the idea that I do not have special wisdom, other people know more about what they need than I do, and deploying my ego and logic from the comfort of my home is not helpful. Find someone who needs something you have an excess of. Give it to them. Treat them as equals. Don't retain control. You won't go far wrong.

Shirish Agarwal: Books and Indian Tourism

Fiction A few days ago somebody asked me and I think it is an often requested to perhaps all fiction readers as to why we like fiction? First of all, reading in itself is told as food for the soul. Because, whenever you write or read anything you don t just read it, you also visualize it. And that visualization is and would be far greater than any attempt in cinema as there are no budget constraints and it takes no more than a minute to visualize a scenario if the writer is any good. You just close your eyes and in a moment you are transported to a different world. This is also what is known as world building . Something fantasy writers are especially gifted in. Also, with the whole parallel Universes being a reality, it is just so much fertile land for imagination that I just cannot believe that it hasn t been worked to death to date. And you do need a lot of patience to make a world, to make characters, to make characters a bit eccentric one way or the other. And you have to know to put into a three, five, or whatever number of acts you want to put in. And then, of course, they have readers like us who dream and add more color to the story than the author did. As we take his, her, or their story and weave countless stories depending on where we are, where we are and who we are. What people need to understand is that not just readers want escapism but writers too want to escape from the human condition. And they find solace in whatever they write. The well-known example of J.R.R. Tolkien is always there. How he must have felt each day coming after war, to somehow find the strength and just dream away, transport himself to a world of hobbits, elves, and other mysterious beings. It surely must have taken a lot of pain from him that otherwise, he would have felt. There are many others. What also does happen now and then, is authors believe in their own intelligence so much, that they commit crimes, but that s par for the course.

Dean Koontz, Odd Apocalypse Currently, I am reading the above title. It is perhaps one of the first horror title books that I have read which has so much fun. The hero has a great sense of wit, humor, and sarcasm that you can cut butter with it. Now if you got that, this is par for the wordplay happening every second paragraph and I m just 100 pages in of the 500-page Novel. Now, while I haven t read the whole book and I m just speculating, what if at the end we realize that the hero all along was or is the villain. Sadly, we don t have many such twisted stories and that too is perhaps because most people used to have black and white rather than grey characters. From all my reading, and even watching web series and whatnot, it is only the Europeans who seem to have a taste for exploring grey characters and giving twists at the end that people cannot anticipate. Even their heroes or heroines are grey characters. and they can really take you for a ride. It is also perhaps how we humans are, neither black nor white but more greyish. Having grey characters also frees the author quite a bit as she doesn t have to use so-called tropes and just led the characters to lead themselves.

Indian Book publishing Industry I do know Bengali stories do have a lot of grey characters, but sadly most of the good works are still in Bengali and not widely published compared to say European or American authors. While there is huge potential in the Indian publishing market for English books and there is also hunger, getting good and cheap publishers is the issue. Just recently SAGE publishing division shut down and this does not augur well for the Indian market. In the past few years, I and other readers have seen some very good publishing houses quit India for one reason or the other. GST has also made the sector more expensive. The only thing that works now and has been for some time is the seconds and thirds market. For e.g. I just bought today about 15-20 books @INR 125/- a kind of belated present for the self. That would be what, at the most 2 USD or 2 Euros per book. I bet even a burger costs more than that, but again India being a price-sensitive market, at these prices the seconds book sells. And these are all my favorite authors, Lee Child, Tom Clancy, Dean Koontz, and so on and so forth. I also saw a lot of fantasy books but they would have to wait for another day.

Tourism in India for Debconf 23 I had shared a while back that I would write a bit about tourism as Debconf or Annual Debian Conference will happen in India next year around this time. I was supposed to write it in the FAQ but couldn t find a place or a corner where I could write it. There are actually two things that people need to be aware of. The one thing that people need to be very aware of is food poisoning or Delhi Belly. This is a far too common sight that I have witnessed especially with westerners when they come to visit India. I am somewhat shocked that it hasn t been shared in the FAQ but then perhaps we cannot cover all the bases therein. I did find this interesting article and would recommend the suggestions given in it wholeheartedly. I would suggest people coming to India to buy and have purifying water tablets with them if they decide to stay back and explore India. Now the problem with tourism is, that one can have as much tourism as one wants. One of the unique ways I found some westerners having the time of their life is buying an Indian Rickshaw or Tuk-Tuk and traveling with it. A few years ago, when I was more adventourous-spirited I was able to meet a few of them. There is also the Race with Rickshaws that happens in Rajasthan and you get to see about 10 odd cities in and around Rajasthan state and get to see the vibrancy in the North. If somebody really wants to explore India, then I would suggest getting down to Goa, specifically, South Goa, meeting with the hippie crowd, and getting one of the hippie guidebooks to India. Most people forget that the Hippies came to India in the 1960s and many of them just never left. Tap water in Pune is ok, have seen and experienced the same in Himachal, Garwhal, and Uttarakhand, although it has been a few years since I have been to those places. North-East is a place I have yet to venture into. India does have a lot of beauty but most people are not clean-conscious so if you go to common tourist destinations, you will find a lot of garbage. Most cities in India do give you an option of homestays and some even offer food, so if you are on a budget as well as wanna experience life with an Indian family, that could be something you could look into. So you can see and share about India with different eyes. There is casteism, racism, and all that. Generally speaking, you would see it wielded a lot more in your face in North India than in South India where it is there but far more subtle. About food, what has been shared in the India BOF. Have to say, it doesn t even scratch the surface. If you stay with an Indian family, there is probably a much better chance of exploring the variety of food that India has to offer. From the western perspective, we tend to overcook stuff and make food with Masalas but that s the way most people like it. People who have had hot sauces or whatnot would probably find India much easier to adjust to as tastes might be similar to some extent. If you want to socialize with young people, while discos are an option, meetup.com also is a good place. You can share your passions and many people have taken to it with gusto. We also have been hosting Comiccons in India, but I haven t had the opportunity to attend them so far. India has a rich oral culture reach going back a few thousand years, but many of those who are practicing those reside more in villages rather than in cities. And while there have been attempts in the past to record them, most of those have come to naught as money runs out as there is no commercial viability to such projects, but that probably is for another day. In the end, what I have shared is barely a drop in the ocean that is India. Come, have fun, explore, enjoy and invigorate yourself and others

Jonathan Dowland: Introducing Red Hat UBI9 OpenJDK runtime images

A few weeks ago we shipped the first RHEL UBI9-based OpenJDK container images. Universal Base Image (UBI) is an initiative where you can obtain, share and build upon official Red Hat container images without needing a Red Hat subscription. They're exactly the same base images that Red Hat products are built upon, composed entirely of Open Source software. Your precise rights are covered in the EULA. Nowadays we offer two flavours of images, the original style (now termed builder images) and leaner runtime images, which have a subset of the JDK, and no build tools like Maven, etc. We provide JDK11 and JDK17 for UBI9:
podman pull registry.access.redhat.com/ubi9/openjdk-11
podman pull registry.access.redhat.com/ubi9/openjdk-17
podman pull registry.access.redhat.com/ubi9/openjdk-11-runtime
podman pull registry.access.redhat.com/ubi9/openjdk-17-runtime
In comparison to the UBI8 images, we have done a lot of housecleaning. If you are curious as to exactly what we've changed, you can read the list of commits in this pull request. Perhaps most notable is a change in the way we tune the JVM's memory. In our existing images up to now, partially for legacy reasons, the container start up scripts interrogate the cgroups (v1) virtual filesystems to establish any memory limits imposed on the running container. From that, they calculated a percentage of the memory limit as an absolute value, and then ask the JVM to limit its heap to that calculated sum via the -Xmx flag. This dates back to a time when the JVM was not container aware. It now is, so for the UBI9 images we instead ask the JVM directly for the percentage we want using -XX:MaxRAMPercentage. We've also changed the default percentage from 50% to 80%, to better utilise the memory assigned to Java containers. One big advantage of this is the JVM is cgroups (v2) aware, and the legacy start up scripts we wrote are not. But another is reducing the amount of code we run in the start up scripts, easing maintenance and simplifying the containers as much as possible. Please give them a go, and let me (or us) know what you think!

14 September 2022

Joachim Breitner: rec-def: Program analysis case study

At this week s International Conference on Functional Programming I showed my rec-def Haskell library to a few people. As this crowd appreciates writing compilers, and example from the realm of program analysis is quite compelling.

To Throw or not to throw Here is our little toy language to analyze: It has variables, lambdas and applications, non-recursive (lazy) let bindings and, so that we have something to analyze, a way to throw and to catch exceptions: Given such an expression, we would like to know whether it might throw an exception. Such an analysis is easy to write: We traverse the syntax tree, remembering in the env which of the variables may throw an exception: The most interesting case is the one for Let, where we extend the environment env with the information about the additional variable env_bind, which is calculated from analyzing the right-hand side e1. So far so good:
ghci> someVal = Lam "y" (Var "y")
ghci> canThrow1 $ Throw
True
ghci> canThrow1 $ Let "x" Throw someVal
False
ghci> canThrow1 $ Let "x" Throw (App (Var "x") someVal)
True

Let it rec To spice things up, let us add a recursive let to the language: How can we support this new constructor in canThrow1? Let use naively follow the pattern used for Let: Calculate the analysis information for the variables in env_bind, extend the environment with that, and pass it down: Note that, crucially, we use env', and not just env, when analyzing the right-hand sides. It has to be that way, as all the variables are in scope in all the right-hand sides. In a strict language, such a mutually recursive definition, where env_bind uses env' which uses env_bind is basically unthinkable. But in a lazy language like Haskell, it might just work. Unfortunately, it works only as long as the recursive bindings are not actually recursive, or if they are recursive, they are not used:
ghci> canThrow1 $ LetRec [("x", Throw)] (Var "x")
True
ghci> canThrow1 $ LetRec [("x", App (Var "y") someVal), ("y", Throw)] (Var "x")
True
ghci> canThrow1 $ LetRec [("x", App (Var "x") someVal), ("y", Throw)] (Var "y")
True
But with genuine recursion, it does not work, and simply goes into a recursive cycle:
ghci> canThrow1 $ LetRec [("x", App (Var "x") someVal), ("y", Throw)] (Var "x")
^CInterrupted.
That is disappointing! Do we really have to toss that code and somehow do an explicit fixed-point calculation here? Obscuring our nice declarative code? And possibly having to repeat work (such as traversing the syntax tree) many times that we should only have to do once?

rec-def to the rescue Not with rec-def! Using RBool from Data.Recursive.Bool instead of Bool, we can write the exact same code, as follows: And it works!
ghci> canThrow2 $ LetRec [("x", App (Var "x") someVal), ("y", Throw)] (Var "x")
False
ghci> canThrow2 $ LetRec [("x", App (Var "x") Throw), ("y", Throw)] (Var "x")
True
I find this much more pleasing than the explicit naive fix-pointing you might do otherwise, where you stabilize the result at each LetRec independently: Not only is all that extra work hidden from the programmer, but now also a single traversal of the syntax tree creates, thanks to the laziness, a graph of RBool values, which are then solved under the hood .

The issue with x=x There is one downside worth mentioning: canThrow2 fails to produce a result in case we hit x=x:
ghci> canThrow2 $ LetRec [("x", Var "x")] (Var "x")
^CInterrupted.
This is, after all the syntax tree has been processed and all the map lookups have been resolved, equivalent to
ghci> let x = x in RB.get (x :: RBool)
^CInterrupted.
which also does not work. The rec-def machinery can only kick in if at least one of its function is used on any such cycle, even if it is just a form of identity (which I ~ought to add to the library~ since have added to the library):
ghci> idR x = RB.false   x
ghci> let x = idR x in getR (x :: R Bool)
False
And indeed, if I insert a call to idR in the line then our analyzer will no longer stumble over these nasty recursive equations:
ghci> canThrow2 $ LetRec [("x", Var "x")] (Var "x")
False
It is a bit disappointing to have to do that, but I do not see a better way yet. I guess the def-rec library expects the programmer to have a similar level of sophistication as other tie-the-know tricks with laziness (where you also have to ensure that your definitions are productive and that the sharing is not accidentally lost).

12 September 2022

Petter Reinholdtsen: Time to translate the Bullseye edition of the Debian Administrator's Handbook

(The picture is of the previous edition.) Almost two years after the previous Norwegian Bokm l translation of the "The Debian Administrator's Handbook" was published, a new edition is finally being prepared. The english text is updated, and it is time to start working on the translations. Around 37 percent of the strings have been updated, one way or another, and the translations starting from a complete Debian Buster edition now need to bring their translation up from 63% to 100%. The complete book is licensed using a Creative Commons license, and has been published in several languages over the years. The translations are done by volunteers to bring Linux in their native tongue. The last time I checked, it complete text was available in English, Norwegian Bokm l, German, Indonesian, Brazil Portuguese and Spanish. In addition, work has been started for Arabic (Morocco), Catalan, Chinese (Simplified), Chinese (Traditional), Croatian, Czech, Danish, Dutch, French, Greek, Italian, Japanese, Korean, Persian, Polish, Romanian, Russian, Swedish, Turkish and Vietnamese. The translation is conducted on the hosted weblate project page. Prospective translators are recommeded to subscribe to the translators mailing list and should also check out the instructions for contributors. I am one of the Norwegian Bokm l translators of this book, and we have just started. Your contribution is most welcome. As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

11 September 2022

Dirk Eddelbuettel: RcppArmadillo 0.11.2.4.0 on CRAN: Bugfix and Deprecation

armadillo image Armadillo is a powerful and expressive C++ template library for linear algebra and scientific computing. It aims towards a good balance between speed and ease of use, has a syntax deliberately close to Matlab, and is useful for algorithm development directly in C++, or quick conversion of research code into production environments. RcppArmadillo integrates this library with the R environment and language and is widely used by (currently) 1016 packages other packages on CRAN, downloaded 26.2 million times (per the partial logs from the cloud mirrors of CRAN), and the CSDA paper (preprint / vignette) by Conrad and myself has been cited 493 times according to Google Scholar. This new release (made yesterday) brings three changes. First, it updates the release to the upstream 11.2.4 bugfix release made days ago by Conrad. Second, it contains support for the deprecation transition we are managing in issue #391. In short, the (convenient but non-standard) initialization via use of << has been deprecated upstream. Until all packages are updated, we override this in the RcppArmadillo but aim to become compliant . Out of the over 1000 packages, a mere 25 need small adjustments. I reached out email and PRs, and the response has been great. Eight packages are already updated on CRAN, and several others have already in integrated or merged the change. Lastly, Conrad pointed out that the fastLm() example and application can be written more concisely by using arma::dot(). The full set of changes (since the last CRAN release 0.11.2.3.1) follows.

Changes in RcppArmadillo version 0.11.2.4.0 (2022-09-09)
  • Upgraded to Armadillo release 11.2.4 (Classic Roast)
    • fix handling of std::move() involving matrices constructed with auxiliary memory
  • In the fastLm() examples, use arma::dot() to compute to the inner product (as proposed by Conrad), plus small edits
  • Support optional #define named RCPPARMADILLO_FORCE_DEPRECATE to suppress use of ARMA_IGNORE_DEPRECATED_MARKER permitting use and development under deprecation

Courtesy of my CRANberries, there is a diffstat report relative to previous release. More detailed information is on the RcppArmadillo page. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page. If you like this or other open-source work I do, you can sponsor me at GitHub.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

Shirish Agarwal: Politics, accessibility, books

Politics I have been reading books, both fiction and non-fiction for a long long time. My first book was a comic most probably when I was down with Malaria when I was a kid. I must be around 4-5 years old. Over the years, books have given me great joy and I continue to find nuggets of useful information, both in fiction as well as non-fiction books. So here s to sharing something and how that can lead you to a rabbit hole. This entry would be a bit NSFW as far as language is concerned. NYPD Red 5 by James Patterson First of all, have no clue as to why James Patterson s popularity has been falling. He used to be right there with Lee Child and others, but not so much now. While I try to be mysterious about books, I would give a bit of heads-up so people know what to expect. This is probably more towards the Adult crowd as there is a bit of sex as well as quite a few grey characters. The NYPD Red is a sort of elite police task force that basically is for celebrities. In the book series, they do a lot of ass-kissing (figuratively more than literally). Now the reason I have always liked fiction is that however wild the assumption or presumption is, it does have somewhere a grain of truth. And each and every time I read a book or two, that gets cemented. One of the statements in the book told something about how 9/11 took a lot of police personnel out of the game. First, there were a number of policemen who were patrolling the Two Towers, so they perished literally during the explosion. Then there were policemen who were given the cases to close the cases (bring the cases to conclusion). When you are investigating your own brethren or even civilians who perished 9/11 they must have experienced emotional trauma and no outlet. Mental health even in cops is the same and given similar help as you and me (i.e. next to none.) But both of these were my assumptions. The only statement that was in the book was they lost a lot of bench strength. Even NYFD (New York Fire Department). This led me to me to With Crime At Record Lows, Should NYC Have Fewer Cops? This is more right-wing sentiment and in fact, there have been calls to defund the police. This led me to https://cbcny.org/ and one specific graph. Unfortunately, this tells the story from 2010-2022 but not before. I was looking for data from around 1999 to 2005 because that will tell whether or not it happened. Then I remembered reading in newspapers the year or two later how 9/11 had led NYC to recession. I looked up online and for sure NY was booming before 9/11. One can argue that NYC could come down and that is pretty much possible, everything that goes up comes down, it s a law of nature but it would have been steady rather than abrupt. And once you are in recession, the first thing to go is personnel. So people both from NYPD and NYFD were let go, even though they were needed the most then. As you can see, a single statement in a book can take you to places & time literally. Edit: Addition 11th September There were quite a few people who also died from New York Port Authority and they also lost quite a number of people directly and indirectly and did a lot of patrolling of the water bodies near NYC. Later on, even in their department, there were a lot of early retirements.

Kosovo A couple of days back I had a look at the Debconf 2023 BOF that was done in Kosovo. One of the interesting things that happened during the BOF is when a woman participant chimed in and asks India to recognize Kosovo. Immediately it triggered me and I opened the Kosovo Wikipedia page to get some understanding of the topic. Reading up on it, came to know Russia didn t agree and doesn t recognize Kosovo. Mr. Modi likes Putin and India imports a lot of its oil from Russia. Unrelatedly, but still useful, we rejected to join IPEF. Earlier, we had rejected China s BRI. India has never been as vulnerable as she is now. Our foreign balance has reached record lows. Now India has been importing quite a bit of Russian crude and has been buying arms and ammunition from them. We are also scheduled to buy a couple of warships and submarines etc. We even took arms and ammunition from them on lease. So we can t afford that they are displeased with India. Even though Russia has more than friendly relations with both China and Pakistan. At the same time, the U.S. is back to aiding Pakistan which the mainstream media in India refuses to even cover. And to top all of this, we have the Chip 4 Alliance but that needs its own article, truth be told but we will do with a paragraph  Edit Addition 11th September Seems Kosovo isn t unique in that situation, there are 3-4 states like that. A brief look at worldpopulationreview tells you there are many more.

Chip 4 Alliance For almost a decade I have been screaming about this on my blog as well as everywhere that chip fabrication is a national security thing. And for years, most people deny it. And now we have chip 4 alliance. Now to understand this, you have to understand that China for almost a decade, somewhere around 2014 or so came up with something called the big fund . Now one can argue one way or the other how successful the fund has been, but it has, without doubt, created ripples so strong that the U.S., Taiwan, Japan, and probably South Korea will join and try to stem the tide. Interestingly, in this grouping, South Korea is the weakest in the statements and what they have been saying. Within the group itself, there is a lot of tension and China would use that and there are a number of unresolved issues between the three countries that both China & Russia would exploit. For e.g. the Comfort women between South Korea and Japan. Or the 1985 Accord Agreement between Japan and the U.S. Now people need to understand this, this is not just about China but also about us. If China has 5-6x times India s GDP and their research budget is at the very least 100x times what India spends, how do you think we will be self-reliant? Whom are we fooling? Are we not tired of fooling ourselves  In diplomacy, countries use leverage. Sadly, we let go of some of our most experienced negotiators in 2014 and since then have been singing in the wind

Accessibility, Jitsi, IRC, Element-Desktop The Wikipedia page on Accessibility says the following Accessibility is the design of products, devices, services, vehicles, or environments so as to be usable by people with disabilities. The concept of accessible design and practice of accessible development ensures both direct access (i.e. unassisted) and indirect access meaning compatibility with a person s assistive technology. Now IRC or Internet Relay Chat has been accessible for a long time. I know of even blind people who have been able to navigate IRC quite effortlessly as there has been a lot of work done to make sure all the joints speak to each other so people with one or more disabilities still can use, and contribute without an issue. It does help that IRC and many clients have been there since the 1970s so most of them have had more than enough time to get all the bugs fixed and both text-to-speech and speech-to-text work brilliantly on IRC. Newer software like Jitsi or for that matter Telegram is lacking those features. A few days ago, discovered on Telegram I was shared that Samsung Voice input is also able to do the same. The Samsung Voice Input works wonder as it translates voice to text, I have not yet tried the text-to-speech but perhaps somebody can and they can share whatever the results can be one way or the other. I have tried element-desktop both on the desktop as well as mobile phone and it has been disappointing, to say the least. On the desktop, it is unruly and freezes once in a while, and is buggy. The mobile version is a little better but that s not saying a lot. I prefer the desktop version as I can use the full-size keyboard. The bug I reported has been there since its Riot days. I had put up a bug report even then. All in all, yesterday was disappointing

Russ Allbery: Review: Hogfather

Review: Hogfather, by Terry Pratchett
Series: Discworld #20
Publisher: Harper
Copyright: 1996
Printing: February 2014
ISBN: 0-06-227628-X
Format: Mass market
Pages: 402
Hogfather is the 20th Discworld novel and not a very good place to start. I recommend at least reading Soul Music first for a proper introduction to Susan, and you may want to start with Mort. When we last saw Susan, she was a student at the Quirm College for Young Ladies. Now she's a governess for two adorable youngsters, a job that includes telling them stories and dealing quite capably with monsters in the cellar. (She uses a poker.) It also includes answering questions like whether the Hogfather really exists or whether the presents just come from your parents.
"Look at it this way, then," she said, and took a deep mental breath. "Wherever people are obtuse and absurd... and wherever they have, by even the most generous standards, the attention span of a small chicken in a hurricane and the investigative ability of a one-legged cockroach... and wherever people are inanely credulous, pathetically attached to the certainties of the nursery and, in general, have as much grasp of the physical universe as an oyster has of mountaineering... yes, Twyla: there is a Hogfather.
Meanwhile, the Auditors, last seen meddling with Death in Reaper Man, approach the Assassin's Guild in Ankh-Morpork to hire the assassination of the Hogfather. This rather unusual assignment falls to Mister Teatime, an orphan who was taken in by the guild at an early age and trained to be an assassin. Teatime is a little unnerving, mostly because he enjoys being an assassin. Rather a lot. Hogfather has two major things to recommend it: it's a Death novel, and it features Susan, who is one of my favorite Discworld characters. It also has two major strikes against it, at least for me. The first is relatively minor but, for me, the most irritating. A bit of the way into the story, Pratchett introduces the Oh God of Hangovers fair, that's a good pun and then decides that's a good excuse for nausea and vomiting jokes. A lot of nausea and vomiting jokes. Look. I know a lot of people don't mind this. But I beg authors (and, even more so, filmmakers and cartoonists) to consider whether a joke that some of your audience might like is worth making other parts of your audience feel physically ill while trying to enjoy your work. It's not at all a pleasant experience, and while I handle it better in written form, it still knocks me out of the story and makes me want to skip over scenes with the obnoxious character who won't shut up about it. Thankfully this does stop by the end of the book, but there are several segments in the middle that were rather unpleasant. The second is that Pratchett tries to convince the reader of the mythical importance of the Santa Claus myth (for which Hogfather is an obvious stand-in, if with a Discworld twist), an effort for which I am a highly unsympathetic audience. I'm with Susan above, with an extra helping of deep dislike for telling children who trust you something that's literally untrue. Pratchett does try: he has Death makes a memorable and frequently-quoted point near the end of the book (transcribed below) that I don't entirely agree with but still respect. But still, the book is very invested in convincing Susan that people believing mythology is critically important to humanity, and I have so many problems with the literalness of "believing" and the use of trusting children for this purpose by adults who know better. There are few topics that bring out my grumpiness more than Santa Claus. Grumbling aside, though, I did enjoy this book anyway. Susan is always a delight, and I could read about her adventures as a governess for as long as Pratchett wanted to write them. Death is filling in for the Hogfather for most of the book, which is hilarious because he's far too good at it, in his painfully earnest and literal way, to be entirely safe. I was less fond of Albert's supporting role (who I am increasingly coming to dislike as a character), but the entire scene of Death as a mall Santa is brilliant. And Teatime is an effective, creepy villain, something that the Discworld series doesn't always deliver. The powers arrayed on Discworld are so strong that it can be hard to design a villain who effectively challenges them, but Teatime has a sociopathic Professor Moriarty energy with added creepiness that fills that role in this book satisfyingly. As is typical for Pratchett (at least for me), the plot was serviceable but not the highlight. Pratchett plays in some interesting ways with a child's view of the world, the Unseen University bumbles around as a side plot, and it comes together at the end in a way that makes sense, but the journey is the fun of the story. The conclusion felt a bit gratuitous, there mostly to wrap up the story than something that followed naturally from the previous plot. But it does feature one of the most quoted bits in Discworld:
"All right," said Susan. "I'm not stupid. You're saying humans need... fantasies to make life bearable." REALLY? AS IF IT WAS SOME KIND OF PINK PILL? NO. HUMANS NEED FANTASY TO BE HUMAN. TO BE THE PLACE WHERE THE FALLING ANGEL MEETS THE RISING APE. "Tooth fairies? Hogfathers? Little " YES. AS PRACTICE. YOU HAVE TO START OUT LEARNING TO BELIEVE THE LITTLE LIES. "So we can believe the big ones?" YES. JUSTICE. MERCY. DUTY. THAT SORT OF THING. "They're not the same at all!" YOU THINK SO? THEN TAKE THE UNIVERSE AND GRIND IT DOWN TO THE FINEST POWDER AND SIEVE IT THROUGH THE FINEST SIEVE AND THEN SHOW ME ONE ATOM OF JUSTICE, ONE MOLECULE OF MERCY. AND YET Death waved a hand. AND YET YOU ACT AS IF THERE IS SOME IDEAL ORDER IN THE WORLD, AS IF THERE IS SOME...SOME RIGHTNESS IN THE UNIVERSE BY WHICH IT MAY BE JUDGED. "Yes, but people have got to believe that, or what's the point " MY POINT EXACTLY.
Here's the thing, though: Susan is right. They're not the same sort of thing at all, and Pratchett doesn't present an argument that they are. Death's response is great, but it's also a non sequitur: it is true and correct but has nothing to do with Susan's argument. Justice is not a lie in the sense that Santa Claus is a lie: justice is something that humans can create, just like humans can create gift-giving or a tradition of imaginative story-telling. But this is not at all the same thing as encouraging children to believe in the literal existence of a fat man in red who comes down chimneys to deliver gifts by magic. And Death isn't even correct in Discworld! If one pays careful attention to the story, the consequences he's thinks would follow from the Auditors' attempt on the Hogfather not only don't happen, the exact opposite happens. This is the point of the Unseen University subplot, and it's also what happened in Reaper Man. The Auditors may be trying to kill mythology, but what the books show is that the real danger comes from the backlash. The force they're meddling with is far more powerful and persistent than they are. Death appears to be, by the stated events of the story, completely incorrect in his analysis of Discworld's metaphysics. Maybe Pratchett knows this? He did write a story that contradicts Death's analysis if one reads it carefully. But if so, this is not obvious from the text, or from Susan's reaction to Death's speech, which makes the metaphysics weirdly unsatisfying. So, overall, a mixed bag. Most of the book is very fun, but the metaphysics heavily rest on a pet peeve of mine, and I really could have done without the loving descriptions of the effects of hangovers. This is one of the more famous Discworld novels for the above quote, and on its own this is deserved (it's a great quote), but I think the logic is muddled and the story itself contradicts the implications. A rather odd reading experience. Followed by Jingo in publication order, and Thief of Time thematically. Rating: 7 out of 10

10 September 2022

Andrew Cater: 202209101602 Debian release day - Cambridge - post 2

Definitely settling into a rhythm - we've been joined by smcv in person (and bittin on line). Bullseye testing is now well beyond the standard image testing into the live images.Buster images are gradually being built so there's the added confusion of two sets of wiki editing, two sets of potential edit conflicts ...So six people in a small-ish sitting room, several with multiple laptops running several checks at once. It's all good, as ever.Dining room table has nine machines on it, three packet switches are fairly well full ...

Andrew Cater: 202209101115 Debian release day - Cambridge - Bullseye and Buster testing starting

And I'm over here with the Debian images/media release team in Cambridge.First time together in Cambridge for a long time: several of the usual suspects - RattusRattus, Sledge, Isy and myself. Also in the room are Kartik and egw - I think this is their first time.Chat is now physically in Sledge's sitting room as well as on IRC. The first couple of images are trickling in and tests are starting for Bullseye.
This is going to be a very long day - we've got full tests for Bullseye (Debian 11) and Buster (Debian 10) so double duty. This should be the last release for Buster since this has now passed to LTS.

9 September 2022

Reproducible Builds: Reproducible Builds in August 2022

Welcome to the August 2022 report from the Reproducible Builds project! In these reports we outline the most important things that we have been up to over the past month. As a quick recap, whilst anyone may inspect the source code of free software for malicious flaws, almost all software is distributed to end users as pre-compiled binaries. The motivation behind the reproducible builds effort is to ensure no flaws have been introduced during this compilation process by promising identical results are always generated from a given source, thus allowing multiple third-parties to come to a consensus on whether a build was compromised. As ever, if you are interested in contributing to the project, please visit our Contribute page on our website.

Community news As announced last month, registration is currently open for our in-person summit this year which is due to be held between November 1st November 3rd. The event will take place in Venice (Italy). Very soon we intend to pick a venue reachable via the train station and an international airport. However, the precise venue will depend on the number of attendees. Please see the announcement email for information about how to register.
The US National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA) and the Office of the Director of National Intelligence (ODNI) have released a document called Securing the Software Supply Chain: Recommended Practices Guide for Developers (PDF) as part of their Enduring Security Framework (ESF) work. The document expressly recommends having reproducible builds as part of advanced recommended mitigations, along with hermetic builds. Page 31 (page 35 in the PDF) says:
Reproducible builds provide additional protection and validation against attempts to compromise build systems. They ensure the binary products of each build system match: i.e., they are built from the same source, regardless of variable metadata such as the order of input files, timestamps, locales, and paths. Reproducible builds are those where re-running the build steps with identical input artifacts results in bit-for-bit identical output. Builds that cannot meet this must provide a justification why the build cannot be made reproducible.
The full press release is available online.
On our mailing list this month, Marc Prud hommeaux posted a feature request for diffoscope which additionally outlines a project called The App Fair, an autonomous distribution network of free and open-source macOS and iOS applications, where validated apps are then signed and submitted for publication .
Author/blogger Cory Doctorow posted published a provocative blog post this month titled Your computer is tormented by a wicked god . Touching on Ken Thompson s famous talk, Reflections on Trusting Trust , the early goals of Secure Computing and UEFI firmware interfaces:
This is the core of a two-decade-old debate among security people, and it s one that the benevolent God faction has consistently had the upper hand in. They re the curated computing advocates who insist that preventing you from choosing an alternative app store or side-loading a program is for your own good because if it s possible for you to override the manufacturer s wishes, then malicious software may impersonate you to do so, or you might be tricked into doing so. [..] This benevolent dictatorship model only works so long as the dictator is both perfectly benevolent and perfectly competent. We know the dictators aren t always benevolent. [ ] But even if you trust a dictator s benevolence, you can t trust in their perfection. Everyone makes mistakes. Benevolent dictator computing works well, but fails badly. Designing a computer that intentionally can t be fully controlled by its owner is a nightmare, because that is a computer that, once compromised, can attack its owner with impunity.

Lastly, Chengyu HAN updated the Reproducible Builds website to correct an incorrect Git command. [ ]

Debian In Debian this month, the essential and required package sets became 100% reproducible in Debian bookworm on the amd64 and arm64 architectures. These two subsets of the full Debian archive refer to Debian package priority levels as described in the 2.5 Priorities section of the Debian Policy there is no canonical minimal installation package set in Debian due to its diverse methods of installation. As it happens, these package sets are not reproducible on the i386 architecture because the ncurses package on that architecture is not yet reproducible, and the sed package currently fails to build from source on armhf too. The full list of reproducible packages within these package sets can be viewed within our QA system, such as on the page of required packages in amd64 and the list of essential packages on arm64, both for Debian bullseye.
It recently has become very easy to install reproducible Debian Docker containers using podman on Debian bullseye:
$ sudo apt install podman
$ podman run --rm -it debian:bullseye bash
The (pre-built) image used is itself built using debuerrotype, as explained on docker.debian.net. This page also details how to build the image yourself and what checksums are expected if you do so.
Related to this, it has also become straightforward to reproducibly bootstrap Debian using mmdebstrap, a replacement for the usual debootstrap tool to create Debian root filesystems:
$ SOURCE_DATE_EPOCH=$(date --utc --date=2022-08-29 +%s) mmdebstrap unstable > unstable.tar
This works for (at least) Debian unstable, bullseye and bookworm, and is tested automatically by a number of QA jobs set up by Holger Levsen (unstable, bookworm and bullseye)
Work has also taken place to ensure that the canonical debootstrap and cdebootstrap tools are also capable of bootstrapping Debian reproducibly, although it currently requires a few extra steps:
  1. Clamping the modification time of files that are newer than $SOURCE_DATE_EPOCH to be not greater than SOURCE_DATE_EPOCH.
  2. Deleting a few files. For debootstrap, this requires the deletion of /etc/machine-id, /var/cache/ldconfig/aux-cache, /var/log/dpkg.log, /var/log/alternatives.log and /var/log/bootstrap.log, and for cdebootstrap we also need to delete the /var/log/apt/history.log and /var/log/apt/term.log files as well.
This process works at least for unstable, bullseye and bookworm and is now being tested automatically by a number of QA jobs setup by Holger Levsen [ ][ ][ ][ ][ ][ ]. As part of this work, Holger filed two bugs to request a better initialisation of the /etc/machine-id file in both debootstrap [ ] and cdebootstrap [ ].
Elsewhere in Debian, 131 reviews of Debian packages were added, 20 were updated and 27 were removed this month, adding to our extensive knowledge about identified issues. Chris Lamb added a number of issue types, including: randomness_in_browserify_output [ ], haskell_abi_hash_differences [ ], nondeterministic_ids_in_html_output_generated_by_python_sphinx_panels [ ]. Lastly, Mattia Rizzolo removed the deterministic flag from the captures_kernel_variant flag [ ].

Other distributions Vagrant Cascadian posted an update of the status of Reproducible Builds in GNU Guix, writing that:
Ignoring the pesky unknown packages, it is more like ~93% reproducible and ~7% unreproducible... that feels a bit better to me! These numbers wander around over time, mostly due to packages moving back into an "unknown" state while the build farms catch up with each other... although the above numbers seem to have been pretty consistent over the last few days.
The post itself contains a lot more details, including a brief discussion of tooling. Elsewhere in GNU Guix, however, Vagrant updated a number of packages such as itpp [ ], perl-class-methodmaker [ ], libnet [ ], directfb [ ] and mm-common [ ], as well as updated the version of reprotest to 0.7.21 [ ]. In openSUSE, Bernhard M. Wiedemann published his usual openSUSE monthly report.

diffoscope diffoscope is our in-depth and content-aware diff utility. Not only can it locate and diagnose reproducibility issues, it can provide human-readable diffs from many kinds of binary formats. This month, Chris Lamb prepared and uploaded versions 220 and 221 to Debian, as well as made the following changes:
  • Update external_tools.py to reflect changes to xxd and the vim-common package. [ ]
  • Depend on the dedicated xxd package now, not the vim-common package. [ ]
  • Don t crash if we can open a PDF file using the PyPDF library, but cannot subsequently parse the annotations within. [ ]
In addition, Vagrant Cascadian updated diffoscope in GNU Guix, first to to version 220 [ ] and later to 221 [ ].

Community news The Reproducible Builds project aims to fix as many currently-unreproducible packages as possible as well as to send all of our patches upstream wherever appropriate. This month we created a number of patches, including:

Testing framework The Reproducible Builds project runs a significant testing framework at tests.reproducible-builds.org, to check packages and other artifacts for reproducibility. This month, Holger Levsen made the following changes:
  • Debian-related changes:
    • Temporarily add Debian unstable deb-src lines to enable test builds a Non-maintainer Upload (NMU) campaign targeting 708 sources without .buildinfo files found in Debian unstable, including 475 in bookworm. [ ][ ]
    • Correctly deal with the Debian Edu packages not being installable. [ ]
    • Finally, stop scheduling stretch. [ ]
    • Make sure all Ubuntu nodes have the linux-image-generic kernel package installed. [ ]
  • Health checks & view:
    • Detect SSH login problems. [ ]
    • Only report the first uninstallable package set. [ ]
    • Show new bootstrap jobs. [ ] and debian-live jobs. [ ] in the job health view.
    • Fix regular expression to detect various zombie jobs. [ ]
  • New jobs:
    • Add a new job to test reproducibility of mmdebstrap bootstrapping tool. [ ][ ][ ][ ]
    • Run our new mmdebstrap job remotely [ ][ ]
    • Improve the output of the mmdebstrap job. [ ][ ][ ]
    • Adjust the mmdebstrap script to additionally support debootstrap as well. [ ][ ][ ]
    • Work around mmdebstrap and debootstrap keeping logfiles within their artifacts. [ ][ ][ ]
    • Add support for testing cdebootstrap too and add such a job for unstable. [ ][ ][ ]
    • Use a reproducible value for SOURCE_DATE_EPOCH for all our new bootstrap jobs. [ ]
  • Misc changes:
    • Send the create_meta_pkg_sets notification to #debian-reproducible-changes instead of #debian-reproducible. [ ]
In addition, Roland Clobus re-enabled the tests for live-build images [ ] and added a feature where the build would retry instead of give up when the archive was synced whilst building an ISO [ ], and Vagrant Cascadian added logging to report the current target of the /bin/sh symlink [ ].

Contact As ever, if you are interested in contributing to the Reproducible Builds project, please visit our Contribute page on our website. However, you can get in touch with us via:

8 September 2022

Antoine Beaupr : Complaint about Canada's phone cartel

I have just filed a complaint with the CRTC about my phone provider's outrageous fees. This is a copy of the complaint.
I am traveling to Europe, specifically to Ireland, for a 6 days for a work meeting. I thought I could use my phone there. So I looked at my phone provider's services in Europe, and found the "Fido roaming" services: https://www.fido.ca/mobility/roaming The fees, at the time of writing, at fifteen (15!) dollars PER DAY to get access to my regular phone service (not unlimited!!). If I do not use that "roaming" service, the fees are:
  • 2$/min
  • 0.75$/text
  • 10$/20MB
That is absolutely outrageous. Any random phone plan in Europe will be cheaper than this, by at least one order of magnitude. Just to take any example: https://www.tescomobile.ie/sim-only-plans.aspx Those fine folks offer a one-time, prepaid plan for 15 for 28 days which includes:
  • unlimited data
  • 1000 minutes
  • 500 text messages
  • 12GB data elsewhere in Europe
I think it's absolutely scandalous that telecommunications providers in Canada can charge so much money, especially since the most prohibitive fee (the "non-prepaid" plans) are automatically charged if I happen to forget to remove my sim card or put my phone in "airplane mode". As advised, I have called customer service at Fido for advice on how to handle this situation. They have confirmed those are the only plans available for travelers and could not accommodate me otherwise. I have notified them I was in the process of filing this complaint. I believe that Canada has become the technological dunce of the world, and I blame the CRTC for its lack of regulation in that matter. You should not allow those companies to grow into such a cartel that they can do such price-fixing as they wish. I haven't investigated Fido's competitors, but I will bet at least one of my hats that they do not offer better service. I attach a screenshot of the Fido page showing those outrageous fees.
I have no illusions about this having any effect. I thought of filing such a complain after the Rogers outage as well, but felt I had less of a standing there because I wasn't affected that much (e.g. I didn't have a life-threatening situation myself). This, however, was ridiculous and frustrating enough to trigger this outrage. We'll see how it goes...
"We will respond to you within 10 working days."

Response from CRTC They did respond within 10 days. Here is the full response:
Dear Antoine Beaupr : Thank you for contacting us about your mobile telephone international roaming service plan rates concern with Fido Solutions Inc. (Fido). In Canada, mobile telephone service is offered on a competitive basis. Therefore, the Canadian Radio-television and Telecommunications Commission (CRTC) is not involved in Fido's terms of service (including international roaming service plan rates), billing and marketing practices, quality of service issues and customer relations. If you haven't already done so, we encourage you to escalate your concern to a manager if you believe the answer you have received from Fido's customer service is not satisfactory. Based on the information that you have provided, this may also appear to be a Competition Bureau matter. The Competition Bureau is responsible for administering and enforcing the Competition Act, and deals with issues such as false or misleading representations, deceptive marketing practices and collusion. You can reach the Competition Bureau by calling 1-800-348-5358 (toll-free), by TTY (for deaf and hard of hearing people) by calling 1-866-694-8389 (toll-free). For more contact information, please visit http://www.competitionbureau.gc.ca/eic/site/cb-bc.nsf/eng/00157.html When consumers are not satisfied with the service they are offered, we encourage them to compare the products and services of other providers in their area and look for a company that can better match their needs. The following tool helps to show choices of providers in your area: https://crtc.gc.ca/eng/comm/fourprov.htm Thank you for sharing your concern with us.
In other words, complain with Fido, or change providers. Don't complain to us, we don't manage the telcos, they self-regulate. Great job, CRTC. This is going great. This is exactly why we're one of the most expensive countries on the planet for cell phone service.

Live chat with Fido Interestingly, the day after I received that response from the CRTC, I received this email from Fido, while traveling:
Date: Tue, 13 Sep 2022 10:10:00 -0400 From: Fido DONOTREPLY@fido.ca To: REDACTED Subject: Courriel d avis d itin rance Fido Roaming Welcome Confirmation Fido Date : 13 septembre 2022
Num ro de compte : [redacted] Bonjour
Antoine Beaupr ! Nous vous crivons pour vous indiquer qu au moins un utilisateur inscrit votre compte s est r cemment connect un r seau en itin rance.
Vous trouverez ci-dessous le message texte de bienvenue en itin rance envoy l utilisateur (ou aux utilisateurs), qui contenait les tarifs d itin rance
applicables. Message texte de bienvenue en itin rance Destinataire : REDACTED Date et heure : 2022-09-13 / 10:10:00
Allo, ici Fido : Bienvenue destination! Vous tes inscrit Fido Nomade alors utilisez vos donn es, parlez et textez comme vous le faites la
maison. Depuis le 1 mars 2022 le tarif cette destination pour 15 $/jour (+ taxes) et valide tous les jours jusqu' 23 h 59 HE, peu importe le fuseau
horaire dans lequel vous vous trouvez. Bon voyage! Des questions? Consultez fido.ca/m/itinerance ou composez +15149333436 (sans frais). Besoin d aide?
  • PLANIFIEZ UN VOYAGE AVEC Fido NomadeMC
    D couvrez nos options d itin rance et restez en contact l tranger sans vous soucier de votre
    facture.
D tails
  • G rez votre compte
    G rez vos produits et services Fido la maison ou sur la route gr ce Mon
    Compte.
D tails Ce courriel est produit automatiquement; veuillez ne pas y r pondre. Ce courriel (et toute pi ce jointe) est confidentiel. Si vous n tes pas le destinataire,
veuillez supprimer le pr sent message et en d truire toute copie. FIDO SOLUTIONS 800, RUE DE LA GAUCHETI RE OUEST
BUREAU 4000 MONTR AL (QU BEC) H5A 1K3
Fido
I found that message utterly confusing (and yes, I can read french). Basically, it says that some user (presumably me!) connected to the network with roaming. I did just disabled airplane mode on my phone to debug a Syncthing bug but had not enabled roaming. So this message seemed to say that I would be charged 15$ (per DAY!) for roaming from now on. Confused, I tried their live chat to try to clarify things, worried I would get charged even more for calling tech support on *611. This is a transcript of the chat:
F: Hi! What are we doing today? Type in your question or choose from the options below: * Track my Equipment Order * View Bill Online * Payment Options * iPhone 14 Pre-Order A: i received a message about roaming while abroad but i did not enable roaming on my phone, will i be charged anyways? F: I think I know what you re asking for. Select the topic that best matches your request or try rephrasing your question. A: no F: Thank you, this will help us to improve! Would you like to chat with a specialist? Chat with a specialist I'll get a specialist to help you with this. It appears that you're not signed in. Your session may have timed out. To save time and identify your account details, please sign in to My Account.
  • Sign in
  • I'm not able to sign in
Have any questions specific to your Fido account? To service you faster, please identify yourself by completing the form below. A: Personal info Form submitted F: Thank you! I'll connect you with the next available specialist. Your chat is being transferred to a Live Chat agent. Thanks for your patience. We are here to assist you and we kindly ask that our team members be treated with respect and dignity. Please note that abuse directed towards any Consumer Care Specialist will not be tolerated and will result in the termination of your conversation with us. All of our agents are with other customers at the moment. Your chat is in a priority sequence and someone will be with you as soon as possible. Thanks! Thanks for continuing to hold. An agent will be with you as soon as possible. Thank you for your continued patience. We re getting more Live Chat requests than usual so it s taking longer to answer. Your chat is still in a priority sequence and will be answered as soon as an agent becomes available. Thank you so much for your patience we're sorry for the wait. Your chat is still in a priority sequence and will be answered as soon as possible. Hi, I'm [REDACTED] from Fido in [REDACTED]. May I have your name please? A: hi i am antoine, nice to meet you sorry to use the live chat, but it's not clear to me i can safely use my phone to call support, because i am in ireland and i'm worried i'll get charged for the call F: Thank You Antoine , I see you waited to speak with me today, thank you for your patience.Apart from having to wait, how are you today? A: i am good thank you
[... delay ...]
A: should i restate my question? F: Yes please what is the concern you have? A: i have received an email from fido saying i someone used my phone for roaming it's in french (which is fine), but that's the gist of it i am traveling to ireland for a week i do not want to use fido's services here... i have set the phon eto airplane mode for most of my time here F: The SMS just says what will be the charges if you used any services. A: but today i have mistakenly turned that off and did not turn on roaming well it's not a SMS, it's an email F: Yes take out the sim and keep it safe.Turun off or On for roaming you cant do it as it is part of plan. A: wat F: if you used any service you will be charged if you not used any service you will not be charged. A: you are saying i need to physically take the SIM out of the phone? i guess i will have a fun conversation with your management once i return from this trip not that i can do that now, given that, you know, i nee dto take the sim out of this phone fun times F: Yes that is better as most of the customer end up using some kind of service and get charged for roaming. A: well that is completely outrageous roaming is off on the phone i shouldn't get charged for roaming, since roaming is off on the phone i also don't get why i cannot be clearly told whether i will be charged or not the message i have received says i will be charged if i use the service and you seem to say i could accidentally do that easily can you tell me if i have indeed used service sthat will incur an extra charge? are incoming text messages free? F: I understand but it is on you if you used some data SMS or voice mail you can get charged as you used some services.And we cant check anything for now you have to wait for next bill. and incoming SMS are free rest all service comes under roaming. That is the reason I suggested take out the sim from phone and keep it safe or always keep the phone or airplane mode. A: okay can you confirm whether or not i can call fido by voice for support? i mean for free F: So use your Fido sim and call on +1-514-925-4590 on this number it will be free from out side Canada from Fido sim. A: that is quite counter-intuitive, but i guess i will trust you on that thank you, i think that will be all F: Perfect, Again, my name is [REDACTED] and it s been my pleasure to help you today. Thank you for being a part of the Fido family and have a great day! A: you too
So, in other words:
  1. they can't tell me if I've actually been roaming
  2. they can't tell me how much it's going to cost me
  3. I should remove the SIM card from my phone (!?) or turn on airplane mode, but the former is safer
  4. I can call Fido support, but not on the usual *611, and instead on that long-distance-looking phone number, and yes, that means turning off airplane mode and putting the SIM card in, which contradicts step 3
Also notice how the phone number from the live chat (+1-514-925-4590) is different than the one provided in the email (15149333436). So who knows what would have happened if I would have called the latter. The former is mentioned in their contact page. I guess the next step is to call Fido over the phone and talk to a manager, which is what the CRTC told me to do in the first place... I ended up talking with a manager (another 1h phone call) and they confirmed there is no other package available at Fido for this. At best they can provide me with a credit if I mistakenly use the roaming by accident to refund me, but that's it. The manager also confirmed that I cannot know if I have actually used any data before reading the bill, which is issued on the 15th of every month, but only available... three days later, at which point I'll be back home anyways. Fantastic.

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.

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