Search Results: "p2"

26 January 2022

Timo Jyrinki: Unboxing Dell XPS 13 - openSUSE Tumbleweed alongside preinstalled Ubuntu

A look at the 2021 model of Dell XPS 13 - available with Linux pre-installed
I received a new laptop for work - a Dell XPS 13. Dell has been long famous for offering certain models with pre-installed Linux as a supported option, and opting for those is nice for moving some euros/dollars from certain PC desktop OS monopoly towards Linux desktop engineering costs. Notably Lenovo also offers Ubuntu and Fedora options on many models these days (like Carbon X1 and P15 Gen 2).
black box

opened box

accessories and a leaflet about Linux support

laptop lifted from the box, closed

laptop with lid open

Ubuntu running

openSUSE runnin
Obviously a smooth, ready-to-rock Ubuntu installation is nice for most people already, but I need openSUSE, so after checking everything is fine with Ubuntu, I continued to install openSUSE Tumbleweed as a dual boot option. As I m a funny little tinkerer, I obviously went with some special things. I wanted:
  • Ubuntu to remain as the reference supported OS on a small(ish) partition, useful to compare to if trying out new development versions of software on openSUSE and finding oddities.
  • openSUSE as the OS consuming most of the space.
  • LUKS encryption for openSUSE without LVM.
  • ext4 s new fancy fast_commit feature in use during filesystem creation.
  • As a result of all that, I ended up juggling back and forth installation screens a couple of times (even more than shown below, and also because I forgot I wanted to use encryption the first time around).
First boots to pre-installed Ubuntu and installation of openSUSE Tumbleweed as the dual-boot option:
(if the embedded video is not shown, use a direct link)
Some notes from the openSUSE installation:
  • openSUSE installer s partition editor apparently does not support resizing or automatically installing side-by-side another Linux distribution, so I did part of the setup completely on my own.
  • Installation package download hanged a couple of times, only passed when I entered a mirror manually. On my TW I ve also noticed download problems recently, there might be a problem with some mirror I need to escalate.
  • The installer doesn t very clearly show encryption status of the target installation - it took me a couple of attempts before I even noticed the small encrypted column and icon (well, very small, see below), which also did not spell out the device mapper name but only the main partition name. In the end it was going to do the right thing right away and use my pre-created encrypted target partition as I wanted, but it could be a better UX. Then again I was doing my very own tweaks anyway.
  • Let s not go to the details why I m so old-fashioned and use ext4 :)
  • openSUSE s installer does not work fine with HiDPI screen. Funnily the tty consoles seem to be fine and with a big font.
  • At the end of the video I install the two GNOME extensions I can t live without, Dash to Dock and Sound Input & Output Device Chooser.

14 December 2021

Timo Jyrinki: Working and warming up cats

How to disable internal keyboard/touchpad when a cat arrives
I m using an external keyboard (1) and mouse (2), but the laptop lid is usually still open for better cooling. That means the internal keyboard (3) and touchpad (4) made of comfortable materials are open to be used by a cat searching for warmth (7), in the obvious every time case that a normal non-heated nest (6) is not enough.
The problem is, everything goes chaotic at that point in the default configuration. The solution is to have quick shortcuts in my Dash to Dock (8) to both disable (10) and enable (9) keyboard and touchpad at a very rapid pace.It is to be noted that I m not disabling the touch screen (5) by default, because most of the time the cat is not leaning on it there is also the added benefit that if one forgets about the internal keyboard and touchpad disabling and detaches the laptop from the USB-C monitor (11), there s the possibility of using the touch screen and on-screen keyboard to type in the password and tap on the keyboard/touchpad enabling shortcut button again. If also touch screen was disabled, the only way would be to go back to an external keyboard or reboot.So here are the scripts. First, the disabling script (pardon my copy-paste use of certain string manipulation tools):
dconf write /org/gnome/desktop/peripherals/touchpad/send-events "'disabled'"
sudo killall evtest
sudo evtest --grab $(sudo libinput list-devices grep -A 1 "AT Translated Set 2 keyboard" tail -n 1 sed 's/.*\/dev/\/dev/') &
sudo evtest --grab $(sudo libinput list-devices grep -A 1 "Dell WMI" tail -n 1 sed 's/.*\/dev/\/dev/') &
sudo evtest --grab $(sudo libinput list-devices grep -A 1 "Power" grep Kernel tail -n 1 sed 's/.*\/dev/\/dev/') &
sudo evtest --grab $(sudo libinput list-devices grep -A 1 "Power" grep Kernel head -n 1 sed 's/.*\/dev/\/dev/') &
sudo evtest --grab $(sudo libinput list-devices grep -A 1 "Sleep" grep Kernel tail -n 1 sed 's/.*\/dev/\/dev/') &
sudo evtest --grab $(sudo libinput list-devices grep -A 1 "HID" grep Kernel head -n 1 sed 's/.*\/dev/\/dev/') &
sudo evtest --grab $(sudo libinput list-devices grep -A 1 "HID" tail -n 1 sed 's/.*\/dev/\/dev/') &
#sudo evtest --grab $(sudo libinput list-devices grep -A 1 "ELAN" tail -n 1 sed 's/.*\/dev/\/dev/') # Touch screen
And the associated ~/.local/share/applications/disable-internal-input.desktop:
[Desktop Entry]
Version=1.0
Name=Disable internal input
GenericName=Disable internal input
Exec=/bin/bash -c /home/timo/Asiakirjat/helpers/disable-internal-input.sh
Icon=yast-keyboard
Type=Application
Terminal=false
Categories=Utility;Development;
Here s the enabling script:
dconf write /org/gnome/desktop/peripherals/touchpad/send-events "'enabled'"
sudo killall evtest
and the desktop file:
[Desktop Entry]
Version=1.0
Name=Enable internal input
GenericName=Enable internal input
Exec=/bin/bash -c /home/timo/Asiakirjat/helpers/enable-internal-input.sh
Icon=/home/timo/.local/share/icons/hicolor/scalable/apps/yast-keyboard-enable.png
Type=Application
Terminal=false
Categories=Utility;Development;
With these, if I sense a cat or am just proactive enough, I press Super+9. If I m about to detach my laptop from the monitor, I press Super+8. If I forget the latter (usually this is the case) and haven t yet locked the screen, I just tap the enabling icon on the touch screen.

22 November 2021

Paul Tagliamonte: Be careful when using vxlan!

I ve spent a bit of time playing with vxlan - which is very neat, but also incredibly insecure by default.When using vxlan, be very careful to understand how the host is connected to the internet. The kernel will listen on all interfaces for packets, which means hosts accessable to VMs it s hosting (e.g., by bridged interface or a private LAN will accept packets from VMs and inject them into arbitrary VLANs, even ones it s not on.I reported this to the kernel mailing list to no reply with more technical details.The tl;dr is:
  $ ip link add vevx0a type veth peer name vevx0z
  $ ip addr add 169.254.0.2/31 dev vevx0a
  $ ip addr add 169.254.0.3/31 dev vevx0z
  $ ip link add vxlan0 type vxlan id 42 \
    local 169.254.0.2 dev vevx0a dstport 4789
  $ # Note the above 'dev' and 'local' ip are set here
  $ ip addr add 10.10.10.1/24 dev vxlan0
results in vxlan0 listening on all interfaces, not just vevx0z or vevx0a. To prove it to myself, I spun up a docker container (using a completely different network bridge with no connection to any of the interfaces above), and ran a Go program to send VXLAN UDP packets to my bridge host:
$ docker run -it --rm -v $(pwd):/mnt debian:unstable /mnt/spam 172.17.0.1:4789
$
which results in packets getting injected into my vxlan interface
$ sudo tcpdump -e -i vxlan0
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on vxlan0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
21:30:15.746754 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
21:30:15.746773 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
21:30:15.746787 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
21:30:15.746801 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
21:30:15.746815 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
21:30:15.746827 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
21:30:15.746870 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
21:30:15.746885 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
21:30:15.746899 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
21:30:15.746913 de:ad:be:ef:00:01 (oui Unknown) > Broadcast, ethertype IPv4 (0x0800), length 64: truncated-ip - 27706 bytes missing! 33.0.0.0 > localhost: ip-proto-114
10 packets captured
10 packets received by filter
0 packets dropped by kernel
(the program in question is the following:)
  package main
  import (
      "net"
      "os"
      "github.com/mdlayher/ethernet"
      "github.com/mdlayher/vxlan"
  )
  func main()  
      conn, err := net.Dial("udp", os.Args[1])
      if err != nil   panic(err)  
      for i := 0; i < 10; i++  
          vxf := &vxlan.Frame 
              VNI: vxlan.VNI(42),
              Ethernet: &ethernet.Frame 
                  Source:      net.HardwareAddr 0xDE, 0xAD, 0xBE,
0xEF, 0x00, 0x01 ,
                  Destination: net.HardwareAddr 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF ,
                  EtherType:   ethernet.EtherTypeIPv4,
                  Payload:     []byte("Hello, World!"),
              ,
          
          frb, err := vxf.MarshalBinary()
          if err != nil   panic(err)  
          _, err = conn.Write(frb)
          if err != nil   panic(err)  
      
  
When using vxlan, be absolutely sure all hosts that can address any interface on the host are authorized to send arbitrary packets into any VLAN that box can send to, or there s very careful and specific controls and firewalling. Note this includes public interfaces (e.g., dual-homed private network / internet boxes), or any type of dual-homing (VPNs, etc).

21 November 2021

Julian Andres Klode: APT Z3 Solver Basics

Z3 is a theorem prover developed at Microsoft research and available as a dynamically linked C++ library in Debian-based distributions. While the library is a whopping 16 MB, and the solver is a tad slow, it s permissive licensing, and number of tactics offered give it a huge potential for use in solving dependencies in a wide variety of applications. Z3 does not need normalized formulas, but offers higher level abstractions like atmost and atleast and implies, that we will make use of together with boolean variables to translate the dependency problem to a form Z3 understands. In this post, we ll see how we can apply Z3 to the dependency resolution in APT. We ll only discuss the basics here, a future post will explore optimization criteria and recommends.

Translating the universe APT s package universe consists of 3 relevant things: packages (the tuple of name and architecture), versions (basically a .deb), and dependencies between versions. While we could translate our entire universe to Z3 problems, we instead will construct a root set from packages that were manually installed and versions marked for installation, and then build the transitive root set from it by translating all versions reachable from the root set. For each package P in the transitive root set, we create a boolean literal P. We then translate each version P1, P2, and so on. Translating a version means building a boolean literal for it, e.g. P1, and then translating the dependencies as shown below. We now need to create two more clauses to satisfy the basic requirements for debs:
  1. If a version is installed, the package is installed; and vice versa. We can encode this requirement for P above as P == atleast( P1,P2 , 1).
  2. There can only be one version installed. We add an additional constraint of the form atmost( P1,P2 , 1).
We also encode the requirements of the operation.
  1. For each package P that is manually installed, add a constraint P.
  2. For each version V that is marked for install, add a constraint V.
  3. For each package P that is marked for removal, add a constraint !P.

Dependencies Packages in APT have dependencies of two basic forms: Depends and Conflicts, as well as variations like Breaks (identical to Conflicts in solving terms), and Recommends (soft Depends) - we ll ignore those for now. We ll discuss Conflicts in the next section. Let s take a basic dependency list: A Depends: X Y, Z. To represent that dependency, we expand each name to a list of versions that can satisfy the dependency, for example X1 X2 Y1, Z1. Translating this dependency list to our Z3 solver, we create boolean variables X1,X2,Y1,Z1 and define two rules:
  1. A implies atleast( X1,X2,Y1 , 1)
  2. A implies atleast( Z1 , 1)
If there actually was nothing that satisfied the Z requirement, we d have added a rule not A. It would be possible to simply not tell Z3 about the version at all as an optimization, but that adds more complexity, and the not A constraint should not cause too many problems.

Conflicts Conflicts cannot have or in them. A dependency B Conflicts: X, Y means that only one of B, X, and Y can be installed. We can directly encode this in Z3 by using the constraint atmost( B,X,Y , 1). This is an optimized encoding of the constraint: We could have encoded each conflict in the form !B or !X, !B or !X, and so on. Usually this leads to worse performance as it introduces additional clauses.

Complete example Let s assume we start with an empty install and want to install the package a below.
Package: a
Version: 1
Depends: c   b
Package: b
Version: 1
Package: b
Version: 2
Conflicts: x
Package: d
Version: 1
Package: x
Version: 1
The translation in Z3 rules looks like this:
  1. Package rules for a:
    1. a == atleast( a1 , 1) - package is installed iff one version is
    2. atmost( a1 , 1) - only one version may be installed
    3. a a must be installed
  2. Dependency rules for a
    1. implies(a1, atleast( b2, b1 , 1)) the translated dependency above. note that c is gone, it s not reachable.
  3. Package rules for b:
    1. b == atleast( b1,b2 , 1) - package is installed iff one version is
    2. atmost( b1, b2 , 1) - only one version may be installed
  4. Dependencies for b (= 2):
    1. atmost( b2, x1 , 1) - the conflicts between x and b = 2 above
  5. Package rules for x:
    1. x == atleast( x1 , 1) - package is installed iff one version is
    2. atmost( x1 , 1) - only one version may be installed
The package d is not translated, as it is not reachable from the root set a1 , the transitive root set is a1,b1,b2,x1 .

Next iteration: Optimization We have now constructed the basic set of rules that allows us to solve solve our dependency problems (equivalent to SAT), however it might lead to suboptimal solutions where it removes automatically installed packages, or installs more packages than necessary, to name a few examples. In our next iteration, we have to look at introducing optimization; for example, have the minimum number of removals, the minimal number of changed packages, or satisfy as many recommends as possible. We will also look at the upgrade problem (upgrade as many packages as possible), the autoremove problem (remove as many automatically installed packages as possible).

Antoine Beaupr : The last syncmaildir crash

My syncmaildir (SMD) setup failed me one too many times (previously, previously). In an attempt to migrate to an alternative mail synchronization tool, I looked into using my IMAP server again, and found out my mail spool was in a pretty bad shape. I'm comparing mbsync and offlineimap in the next post but this post talks about how I recovered the mail spool so that tools like those could correctly synchronise the mail spool again.

The latest crash On Monday, SMD just started failing with this error:
nov 15 16:12:19 angela systemd[2305]: Starting pull emails with syncmaildir...
nov 15 16:12:22 angela systemd[2305]: smd-pull.service: Succeeded.
nov 15 16:12:22 angela systemd[2305]: Finished pull emails with syncmaildir.
nov 15 16:14:08 angela systemd[2305]: Starting pull emails with syncmaildir...
nov 15 16:14:11 angela systemd[2305]: smd-pull.service: Main process exited, code=exited, status=1/FAILURE
nov 15 16:14:11 angela systemd[2305]: smd-pull.service: Failed with result 'exit-code'.
nov 15 16:14:11 angela systemd[2305]: Failed to start pull emails with syncmaildir.
nov 15 16:16:14 angela systemd[2305]: Starting pull emails with syncmaildir...
nov 15 16:16:17 angela smd-pull[27178]: smd-client: ERROR: Network error.
nov 15 16:16:17 angela smd-pull[27178]: smd-client: ERROR: Unable to get any data from the other endpoint.
nov 15 16:16:17 angela smd-pull[27178]: smd-client: ERROR: This problem may be transient, please retry.
nov 15 16:16:17 angela smd-pull[27178]: smd-client: ERROR: Hint: did you correctly setup the SERVERNAME variable
nov 15 16:16:17 angela smd-pull[27178]: smd-client: ERROR: on your client? Did you add an entry for it in your ssh
nov 15 16:16:17 angela smd-pull[27178]: smd-client: ERROR: configuration file?
nov 15 16:16:17 angela smd-pull[27178]: smd-client: ERROR: Network error
nov 15 16:16:17 angela smd-pull[27188]: register: smd-client@localhost: TAGS: error::context(handshake) probable-cause(network) human-intervention(avoidable) suggested-actions(retry)
nov 15 16:16:17 angela systemd[2305]: smd-pull.service: Main process exited, code=exited, status=1/FAILURE
nov 15 16:16:17 angela systemd[2305]: smd-pull.service: Failed with result 'exit-code'.
nov 15 16:16:17 angela systemd[2305]: Failed to start pull emails with syncmaildir.
What is frustrating is that there's actually no network error here. Running the command by hand I did see a different message, but now I have lost it in my backlog. It had something to do with a filename being too long, and I gave up debugging after a while. This happened suddenly too, which added to the confusion. In a fit of rage I started this blog post and experimenting with alternatives, which led me down a lot of rabbit holes. Reviewing my previous mail crash documentation, it seems most solutions involve talking to an IMAP server, so I figured I would just do that. Wanting to try something new, i gave isync (AKA mbsync) a try. Oh dear, I did not expect how much trouble just talking to my IMAP server would be, which wasn't not isync's fault, for what that's worth. It was the primary tool I used to debug things, and served me well in that regard.

Mailbox corruption The first thing I found out is that certain messages in the IMAP spool were corrupted. mbsync would stop on a FETCH command and Dovecot would give me those errors on the server side.

"wrong W value"
nov 16 15:31:27 marcos dovecot[3621800]: imap(anarcat)<3630489><wAmSzO3QZtfAqAB1>: Error: Mailbox junk: Maildir filename has wrong W value, renamed the file from /home/anarcat/Maildir/.junk/cur/1454623938.M101164P22216.marcos,S=2495,W=2578:2,S to /home/anarcat/Maildir/.junk/cur/1454623938.M101164P22216.marcos,S=2495:2,S
nov 16 15:31:27 marcos dovecot[3621800]: imap(anarcat)<3630489><wAmSzO3QZtfAqAB1>: Error: Mailbox junk: Deleting corrupted cache record uid=1582: UID 1582: Broken virtual size in mailbox junk: read(/home/anarcat/Maildir/.junk/cur/1454623938.M101164P22216.marcos,S=2495,W=2578:2,S): FETCH BODY[] got too little data: 2540 vs 2578
At least this first error was automatically healed by Dovecot (by renaming the file without the W= flag). The problem is that the FETCH command fails and mbsync exits noisily. So you need to constantly restart mbsync with a silly command like:
while ! mbsync -a; do sleep 1; done

"cached message size larger than expected"
nov 16 13:53:08 marcos dovecot[3520770]: imap(anarcat)<3594402><M5JHb+zQ3NLAqAB1>: Error: Mailbox Sent: UID=19288: read(/home/anarcat/Maildir/.Sent/cur/1224790447.M898726P9811V000000000000FE06I00794FB1_0.marvin,S=2588:2,S) failed: Cached message size larger than expected (2588 > 2482, box=Sent, UID=19288) (read reason=mail stream)
nov 16 13:53:08 marcos dovecot[3520770]: imap(anarcat)<3594402><M5JHb+zQ3NLAqAB1>: Error: Mailbox Sent: Deleting corrupted cache record uid=19288: UID 19288: Broken physical size in mailbox Sent: read(/home/anarcat/Maildir/.Sent/cur/1224790447.M898726P9811V000000000000FE06I00794FB1_0.marvin,S=2588:2,S) failed: Cached message size larger than expected (2588 > 2482, box=Sent, UID=19288)
nov 16 13:53:08 marcos dovecot[3520770]: imap(anarcat)<3594402><M5JHb+zQ3NLAqAB1>: Error: Mailbox Sent: UID=19288: read(/home/anarcat/Maildir/.Sent/cur/1224790447.M898726P9811V000000000000FE06I00794FB1_0.marvin,S=2588:2,S) failed: Cached message size larger than expected (2588 > 2482, box=Sent, UID=19288) (read reason=)
nov 16 13:53:08 marcos dovecot[3520770]: imap-login: Panic: epoll_ctl(del, 7) failed: Bad file descriptor
This second problem is much harder to fix, because dovecot does not recover automatically. This is Dovecot complaining that the cached size (the S= field, but also present in Dovecot's metadata files) doesn't match the file size. I wonder if at least some of those messages were corrupted in the OfflineIMAP to syncmaildir migration because part of that procedure is to run the strip_header script to remove content from the emails. That could easily have broken things since the files do not also get renamed.

Workaround So I read a lot of the Dovecot documentation on the maildir format, and wrote an extensive fix script for those two errors. The script worked and mbsync was able to sync the entire mail spool. And no, rebuilding the index files didn't work. Also tried doveadm force-resync -u anarcat which didn't do anything. In the end I also had to do this, because the wrong cache values were also stored elsewhere.
service dovecot stop ; find -name 'dovecot*' -delete; service dovecot start
This would have totally broken any existing clients, but thankfully I'm starting from scratch (except maybe webmail, but I'm hoping it will self-heal as well, assuming it only has a cache and not a full replica of the mail spool).

Incoherence between Maildir and IMAP Unfortunately, the first mbsync was incomplete as it was missing about 15,000 mails:
anarcat@angela:~(main)$ find Maildir -type f -type f -a \! -name '.*'   wc -l 
384836
anarcat@angela:~(main)$ find Maildir-mbsync/ -type f -a \! -name '.*'   wc -l 
369221
As it turns out, mbsync was not at fault here either: this was yet more mail spool corruption. It's actually 26 folders (out of 205) with inconsistent sizes, which can be found with:
for folder in * .[^.]* ; do 
  printf "%s\t%d\n" $folder $(find "$folder" -type f -a \! -name '.*'   wc -l );
done
The special \! -name '.*' bit is to ignore the mbsync metadata, which creates .uidvalidity and .mbsyncstate in every folder. That ignores about 200 files but since they are spread around all folders, which was making it impossible to review where the problem was. Here is what the diff looks like:
--- Maildir-list    2021-11-17 20:42:36.504246752 -0500
+++ Maildir-mbsync-list 2021-11-17 20:18:07.731806601 -0500
@@ -6,16 +6,15 @@
[...]
 .Archives  1
 .Archives.2010 3553
-.Archives.2011 3583
-.Archives.2012 12593
+.Archives.2011 3582
+.Archives.2012 620
 .Archives.2013 8576
 .Archives.2014 11057
-.Archives.2015 8173
+.Archives.2015 8165
 .Archives.2016 54
 .band  34
 .bitbuck   1
@@ -38,13 +37,12 @@
 .couchsurfers  2
-cur    11285
+cur    11280
 .current   130
 .cv    2
 .debbug    262
-.debian    37544
-drafts 1
-.Drafts    4
+.debian    37533
+.Drafts    2
 .drone 241
 .drupal    188
 .drupal-devel  303
[...]

Misfiled messages It's a bit all over the place, but we can already notice some huge differences between mailboxes, for example in the Archives folders. As it turns out, at least 12,000 of those missing mails were actually misfiled: instead of being in the Maildir/.Archives.2012/cur/ folder, they were directly in Maildir/.Archives.2012/. This is something that doesn't matter for SMD (and possibly for notmuch? it does matter, notmuch suddenly found 12,000 new mails) but that definitely matters to Dovecot and therefore mbsync... After moving those files around, we still have 4,000 message missing:
anarcat@angela:~(main)$ find Maildir-mbsync/  -type f -a \! -name '.*'   wc -l 
381196
anarcat@angela:~(main)$ find Maildir/  -type f -a \! -name '.*'   wc -l 
385053
The problem is that those 4,000 missing mails are harder to track. Take, for example, .Archives.2011, which has a single message missing, out of 3,582. And the files are not identical: the checksums don't match after going through the IMAP transport, so we can't use a tool like hashdeep to compare the trees and find why any single file is missing.

"register" folder One big chunk of the 4,000, however, is a special folder called register in my spool, which I am syncing separately (see Securing registration email for details on that setup). That actually covers 3,700 of those messages, so I actually have a more modest 300 messages to figure out, after (easily!) configuring mbsync to sync that folder separately:
 @@ -30,9 +33,29 @@ Slave :anarcat-local:
  # Exclude everything under the internal [Gmail] folder, except the interesting folders
  #Patterns * ![Gmail]* "[Gmail]/Sent Mail" "[Gmail]/Starred" "[Gmail]/All Mail"
  # Or include everything
 -Patterns *
 +#Patterns *
 +Patterns * !register  !.register
  # Automatically create missing mailboxes, both locally and on the server
  #Create Both
  Create slave
  # Sync the movement of messages between folders and deletions, add after making sure the sync works
  #Expunge Both
 +
 +IMAPAccount anarcat-register
 +Host imap.anarc.at
 +User register
 +PassCmd "pass imap.anarc.at-register"
 +SSLType IMAPS
 +CertificateFile /etc/ssl/certs/ca-certificates.crt
 +
 +IMAPStore anarcat-register-remote
 +Account anarcat-register
 +
 +MaildirStore anarcat-register-local
 +SubFolders Maildir++
 +Inbox ~/Maildir-mbsync/.register/
 +
 +Channel anarcat-register
 +Master :anarcat-register-remote:
 +Slave :anarcat-register-local:
 +Create slave

"tmp" folders and empty messages After syncing the "register" messages, I end up with the measly little 160 emails out of sync:
anarcat@angela:~(main)$ find Maildir-mbsync/  -type f -a \! -name '.*'   wc -l 
384900
anarcat@angela:~(main)$ find Maildir/  -type f -a \! -name '.*'   wc -l 
385059
Argh. After more digging, I have found 131 mails in the tmp/ directories of the client's mail spool. Mysterious! On the server side, it's even more files, and not the same ones. Possible that those were mails that were left there during a failed delivery of some sort, during a power failure or some sort of crash? Who knows. It could be another race condition in SMD if it runs while mail is being delivered in tmp/... The first thing to do with those is to cleanup a bunch of empty files (21 on angela):
find .[^.]*/tmp -type f -empty -delete
As it turns out, they are all duplicates, in the sense that notmuch can easily find a copy of files with the same message ID in its database. In other words, this hairy command returns nothing
find .[^.]*/tmp -type f   while read path; do
  msgid=$(grep -m 1  -i ^message-id "$path"   sed 's/Message-ID: //i;s/[<>]//g');
  if notmuch count --exclude=false  "id:$msgid"   grep -q 0; then
    echo "$path <$msgid> not in notmuch" ;
  fi;
done
... which is good. Or, to put it another way, this is safe:
find .[^.]*/tmp -type f -delete
Poof! 314 mails cleaned on the server side. Interestingly, SMD doesn't pick up on those changes at all and still sees files in tmp/ directories on the client side, so we need to operate the same twisted logic there.

notmuch to the rescue again After cleaning that on the client, we get:
anarcat@angela:~(main)$ find Maildir/  -type f -a \! -name '.*'   wc -l 
384928
anarcat@angela:~(main)$ find Maildir-mbsync/  -type f -a \! -name '.*'   wc -l 
384901
Ha! 27 mails difference. Those are the really sticky, unclear ones. I was hoping a full sync might clear that up, but after deleting the entire directory and starting from scratch, I end up with:
anarcat@angela:~(main)$ find Maildir -type f -type f -a \! -name '.*'   wc -l 
385034
anarcat@angela:~(main)$ find Maildir-mbsync -type f -type f -a \! -name '.*'   wc -l 
384993
That is: even more messages missing (now 37). Sigh. Thankfully, this is something notmuch can help with: it can index all files by Message-ID (which I learned is case-insensitive, yay) and tell us which messages don't make it through. Considering the corruption I found in the mail spool, I wouldn't be the least surprised those messages are just skipped by the IMAP server. Unfortunately, there's nothing on the Dovecot server logs that would explain the discrepancy. Here again, notmuch comes to the rescue. We can list all message IDs to figure out that discrepancy:
notmuch search --exclude=false --output=messages '*'   pv -s 18M   sort > Maildir-msgids
notmuch --config=.notmuch-config-mbsync search --exclude=false --output=messages '*'   pv -s 18M   sort > Maildir-mbsync-msgids
And then we can see how many messages notmuch thinks are missing:
$ wc -l *msgids
372723 Maildir-mbsync-msgids
372752 Maildir-msgids
That's 29 messages. Oddly, it doesn't exactly match the find output:
anarcat@angela:~(main)$ find Maildir-mbsync -type f -type f -a \! -name '.*'   wc -l 
385204
anarcat@angela:~(main)$ find Maildir -type f -type f -a \! -name '.*'   wc -l 
385241
That is 10 more messages. Ugh. But actually, I know what those are: more misfiled messages (in a .folder/draft/ directory, bizarrely, so the totals actually match. In the notmuch output, there's a lot of stuff like this:
id:notmuch-sha1-fb880d673e24f5dae71b6b4d825d4a0d5d01cde4
Those are messages without a valid Message-ID. Notmuch (presumably) constructs one based on the file's checksum. Because the files differ between the IMAP server and the local mail spool (which is unfortunate, but possibly inevitable), those do not match. There are exactly the same number of those on both sides, so I'll go ahead and assume those are all accounted for. What remains is:
anarcat@angela:~(main)$ diff -u Maildir-mbsync-msgids Maildir-msgids    grep '^\-[^-]'   grep -v sha1   wc -l 
2
anarcat@angela:~(main)$ diff -u Maildir-mbsync-msgids Maildir-msgids    grep '^\+[^+]'   grep -v sha1   wc -l 
21
anarcat@angela:~(main)$ 
ie. 21 missing from mbsync, and, surprisingly, 2 missing from the original mail spool. Further inspection also showed they were all messages with some sort of "corruption": no body and only headers. I am not sure that is a legal email format in the first place. Since they were mostly spam or administrative emails ("You have been unsubscribed from mailing list..."), it seems fairly harmless to ignore those.

Conclusion As we'll see in the next article, SMD has stellar performance. But that comes at a huge cost: it accesses the mail storage directly. This can (and has) created significant problems on the mail server. It's unclear exactly why those things happen, but Dovecot expects a particular storage format on its file, and it seems unwise to bypass that. In the future, I'll try to remember to avoid that, especially since mechanisms like SMD require special server access (SSH) which, in the long term, I am not sure I want to maintain or expect. In other words, just talking with an IMAP server opens up a lot more possibilities of hosting than setting up a custom synchronisation protocol over SSH. It's also safer and more reliable, as we have seen. Thankfully, I've been able to recover from all the errors I could find, but it could have gone differently and it would have been possible for SMD to permanently corrupt significant part of my mail archives. In the end, however, the last drop was just another weird bug which, ironically, SMD mysteriously recovered from on its own while I was writing this documentation and migrating away from it. In any case, I recommend SMD users start looking for alternatives. The project has been archived upstream, and the Debian package has been orphaned. I have seen significant mail box corruption, including entire mail spool destruction, mostly due to incorrect locking code. I have filed a release-critical bug in Debian to make sure it doesn't ship with Debian bookworm. Alternatives like mbsync provide fast and reliable transport, including over SSH. See the next article for further discussion of the alternatives.

6 November 2021

Reproducible Builds: Reproducible Builds in October 2021

Welcome to the October 2021 report from the Reproducible Builds project!
This month Samanta Navarro posted to the oss-security security mailing on a novel category of exploit in the .tar archive format, where a single .tar file contains different contents depending on the tar utility being used. Naturally, this has consequences for reproducible builds as Samanta goes onto reply:

Arch Linux uses libarchive (bsdtar) in its build environment. The default tar program installed is GNU tar. It is possible to create a source distribution which leads to different files seen by the build environment than compared to a careful reviewer and other Linux distributions.
Samanta notes that addressing the tar utilities themselves will not be a sufficient fix:
I have submitted bug reports and patches to some projects but eventually I had to conclude that the problem itself cannot be fixed by these implementations alone. The best choice for these tools would be to only allow archives which are fully compatible to standards but this in turn would render a lot of archives broken.
Reproducible builds, with its twin ideas of reaching consensus on the build outputs as well as precisely recording and describing the build environment, would help address this problem at a higher level.
Codethink announced that they had achieved ISO-26262 ASIL D Tool Certification, a way of determining specific safety standards for software. Codethink used open source tooling to achieve this, but they also leverage:
Reproducibility, repeatability and traceability of builds, drawing heavily on best-practices championed by the Reproducible Builds project.

Elsewhere on the internet, according to a comment on Hacker News, Microsoft are now comparing NPM Javascript packages with their original source repositories:
I got a PR in my repository a few days ago leading back to a team trying to make it easier for packages to be reproducible from source.

Lastly, Martin Monperrus started an interesting thread on our mailing list about Github, specifically that their autogenerated release tarballs are not deterministic . The thread generated a significant number of replies that are worth reading.

Events and presentations

Community news On our mailing list this month:
There were quite a few changes to the Reproducible Builds website and documentation this month as well, including Feng Chai updating some links on our publications page [ ] and marco updated our project metadata around the Bitcoin Core building guide [ ].
Lastly, we ran another productive meeting on IRC during October. A full set of notes from the meeting is available to view.

Distribution work Qubes was heavily featured in the latest edition of Linux Weekly News, and a significant section was dedicated to discussing reproducibility. For example, it was mentioned that the Qubes project has been working on incorporating reproducible builds into its continuous integration (CI) infrastructure . But the LWN article goes on to describe that:
The current goal is to be able to build the Qubes OS Debian templates solely from packages that can be built reproducibly. Templates in Qubes OS are VM images that can be used to start an application qube quickly based on the template. The qube will have read-only access to the root filesystem of the template, so that the same root filesystem can be shared with multiple application qubes. There are official templates for several variants of both Fedora and Debian, as well as community maintained templates for several other distributions.
You can view the whole article on LWN, and Fr d ric also published a lengthy summary about their work on reproducible builds in Qubes as well for those wishing to learn more.
In Debian this month, 133 reviews of Debian packages were added, 81 were updated and 24 were removed this month, adding to Debian s ever-growing knowledge about identified issues. A number of issues were categorised and added by Chris Lamb and Vagrant Cascadian too [ ][ ][ ]. In addition, work on alternative snapshot service has made progress by Fr d ric Pierret and Holger Levsen this month, including moving from the existing host (snapshot.notset.fr) to snapshot.reproducible-builds.org (more info) thanks to OSUOSL for the machine and hosting and Debian for the disks.
Finally, Bernhard M. Wiedemann posted his monthly reproducible builds status 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 made the following changes, including preparing and uploading versions 186, 187, 188 and 189 to Debian
  • New features:
    • Add support for Python Sphinx inventory files (usually named objects.inv on-disk). [ ]
    • Add support for comparing .pyc files. Thanks to Sergei Trofimovich for the inspiration. [ ]
    • Try some alternative suffixes (e.g. .py) to support distributions that strip or retain them. [ ][ ]
  • Bug fixes:
    • Fix Python decompilation tests under Python 3.10+ [ ] and for Python 3.7 [ ].
    • Don t raise a traceback if we cannot unmarshal Python bytecode. This is in order to support Python 3.7 failing to load .pyc files generated with newer versions of Python. [ ]
    • Skip Python bytecode testing where we do not have an expected diff. [ ]
  • Codebase improvements:
    • Use our file_version_is_lt utility instead of accepting both versions of uImage expected diff. [ ]
    • Split out a custom call to assert_diff for a .startswith equivalent. [ ]
    • Use skipif instead of manual conditionals in some tests. [ ]
In addition, Jelle van der Waa added external tool references for Arch Linux for ocamlobjinfo, openssl and ffmpeg [ ][ ][ ] and added Arch Linux as a Continuous Integration (CI) test target. [ ] and Vagrant Cascadian updated the testsuite to skip Python bytecode comparisons when file(1) is older than 5.39. [ ] as well as added external tool references for the Guix distribution for dumppdf and ppudump. [ ][ ]. Vagrant Cascadian also updated the diffoscope package in GNU Guix [ ][ ]. Lastly, Guangyuan Yang updated the FreeBSD package name on the website [ ], Mattia Rizzolo made a change to override a new Lintian warning due to the new test files [ ], Roland Clobus added support to detect and log if the GNU_BUILD_ID field in an ELF binary been modified [ ], Sandro J ckel updated a number of helpful links on the website [ ] and Sergei Trofimovich made the uImage test output support file() version 5.41 [ ].

reprotest reprotest is the Reproducible Build s project end-user tool to build same source code twice in widely differing environments, checking the binaries produced by the builds for any differences. This month, reprotest version 0.7.18 was uploaded to Debian unstable by Holger Levsen, which also included a change by Holger to clarify that Python 3.9 is used nowadays [ ], but it also included two changes by Vasyl Gello to implement realistic CPU architecture shuffling [ ] and to log the selected variations when the verbosity is configured at a sufficiently high level [ ]. Finally, Vagrant Cascadian updated reprotest to version 0.7.18 in GNU Guix.

Upstream patches The Reproducible Builds project detects, dissects and attempts to fix unreproducible packages. We try to send all of our patches upstream where appropriate. We authored a large number of such patches this month, including:

Testing framework The Reproducible Builds project runs a testing framework at tests.reproducible-builds.org, to check packages and other artifacts for reproducibility. This month, the following changes were made:
  • Holger Levsen:
    • Debian-related changes:
      • Incorporate a fix from bremner into builtin-pho related to binary-NMUs. [ ]
      • Keep bullseye environments around longer, in an attempt to fix a Jenkins issue. [ ]
      • Improve the documentation of buildinfos.debian.net. [ ]
      • Improve documentation for the builtin-pho setup. [ ][ ]
    • OpenWrt-related changes:
      • Also use -j1 for better debugging. [ ]
      • Document that that Python 3.x is now used. [ ]
      • Enable further debugging for the toolchain build. [ ]
    • New snapshot.reproducible-builds.org service:
      • Actually add new node. [ ][ ]
      • Install xfsprogs on snapshot.reproducible-builds.org. [ ]
      • Create account for fpierret on new node. [ ]
      • Run node_health_check job on new node too. [ ]
  • Mattia Rizzolo:
    • Debian-related changes:
      • Handle schroot errors when invoking diffoscope instead of masking them. [ ][ ]
      • Declare and define some variables separately to avoid masking the subshell return code. [ ]
      • Fix variable name. [ ]
      • Improve log reporting. [ ]
      • Execute apt-get update with the -q argument to get more decent logs. [ ]
      • Set the Debian HTTP mirror and proxy for snapshot.reproducible-builds.org. [ ]
      • Install the libarchive-tools package (instead of bsdtar) when updating Jenkins nodes. [ ]
    • Be stricter about errors when starting the node agent [ ] and don t overwrite NODE_NAME so that we can expect Jenkins to properly set for us [ ].
    • Explicitly warn if the NODE_NAME is not a fully-qualified domain name (FQDN). [ ]
    • Document whether a node runs in the future. [ ]
    • Disable postgresql_autodoc as it not available in bullseye. [ ]
    • Don t be so eager when deleting schroot internals, call to schroot -e to terminate the schroots instead. [ ]
    • Only consider schroot underlays for deletion that are over a month old. [ ][ ]
    • Only try to unmount /proc if it s actually mounted. [ ]
    • Move the db_backup task to its own Jenkins job. [ ]
Lastly, Vasyl Gello added usage information to the reproducible_build.sh script [ ].

Contributing 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:

2 November 2021

Enrico Zini: help2man and subcommands

help2man is quite nice for autogenerating manpages from command line help, making sure that they stay up to date as command line options evolve. It works quite well, except for commands with subcommands, like Python programs that use argparse's add_subparser. So, here's a quick hack that calls help2man for each subcommand, and stitches everything together in a simple manpage.
#!/usr/bin/python3
import re
import shutil
import sys
import subprocess
import tempfile
# TODO: move to argparse
command = sys.argv[1]
# Use setup.py to get the program version
res = subprocess.run([sys.executable, "setup.py", "--version"], stdout=subprocess.PIPE, text=True, check=True)
version = res.stdout.strip()
# Call the main commandline help to get a list of subcommands
res = subprocess.run([sys.executable, command, "--help"], stdout=subprocess.PIPE, text=True, check=True)
subcommands = re.sub(r'^.+\ (.+)\ .+$', r'\1', res.stdout, flags=re.DOTALL).split(',')
# Generate a help2man --include file with an extra section for each subcommand
with tempfile.NamedTemporaryFile("wt") as tf:
    print("[>DESCRIPTION]", file=tf)
    for subcommand in subcommands:
        res = subprocess.run(
                ["help2man", f"--name= command ", "--section=1",
                 "--no-info", "--version-string=dummy", f"./ command   subcommand "],
                stdout=subprocess.PIPE, text=True, check=True)
        subcommand_doc = re.sub(r'^.+.SH DESCRIPTION', '', res.stdout, flags=re.DOTALL)
        print(".SH ", subcommand.upper(), " SUBCOMMAND", file=tf)
        tf.write(subcommand_doc)
    with open(f" command .1.in", "rt") as fd:
        shutil.copyfileobj(fd, tf)
    tf.flush()
    # Call help2man on the main command line help, with the extra include file
    # we just generated
    subprocess.run(
            ["help2man", f"--include= tf.name ", f"--name= command ",
             "--section=1", "--no-info", f"--version-string= version ",
             "--output=arkimaps.1", "./arkimaps"],
            check=True)

5 September 2021

Reproducible Builds: Reproducible Builds in August 2021

Welcome to the latest report from the Reproducible Builds project. In this post, we round up the important things that happened in the world of reproducible builds in August 2021. As always, if you are interested in contributing to the project, please visit the Contribute page on our website.
There were a large number of talks related to reproducible builds at DebConf21 this year, the 21st annual conference of the Debian Linux distribution (full schedule):
PackagingCon (@PackagingCon) is new conference for developers of package management software as well as their related communities and stakeholders. The virtual event, which is scheduled to take place on the 9th and 10th November 2021, has a mission is to bring different ecosystems together: from Python s pip to Rust s cargo to Julia s Pkg, from Debian apt over Nix to conda and mamba, and from vcpkg to Spack we hope to have many different approaches to package management at the conference . A number of people from reproducible builds community are planning on attending this new conference, and some may even present. Tickets start at $20 USD.
As reported in our May report, the president of the United States signed an executive order outlining policies aimed to improve the cybersecurity in the US. The executive order comes after a number of highly-publicised security problems such as a ransomware attack that affected an oil pipeline between Texas and New York and the SolarWinds hack that affected a large number of US federal agencies. As a followup this month, however, a detailed fact sheet was released announcing a number large-scale initiatives and that will undoubtedly be related to software supply chain security and, as a result, reproducible builds.
Lastly, We ran another productive meeting on IRC in August (original announcement) which ran for just short of two hours. A full set of notes from the meeting is available.

Software development kpcyrd announced an interesting new project this month called I probably didn t backdoor this which is an attempt to be:
a practical attempt at shipping a program and having reasonably solid evidence there s probably no backdoor. All source code is annotated and there are instructions explaining how to use reproducible builds to rebuild the artifacts distributed in this repository from source. The idea is shifting the burden of proof from you need to prove there s a backdoor to we need to prove there s probably no backdoor . This repository is less about code (we re going to try to keep code at a minimum actually) and instead contains technical writing that explains why these controls are effective and how to verify them. You are very welcome to adopt the techniques used here in your projects. ( )
As the project s README goes on the mention: the techniques used to rebuild the binary artifacts are only possible because the builds for this project are reproducible . This was also announced on our mailing list this month in a thread titled i-probably-didnt-backdoor-this: Reproducible Builds for upstreams. kpcyrd also wrote a detailed blog post about the problems surrounding Linux distributions (such as Alpine and Arch Linux) that distribute compiled Python bytecode in the form of .pyc files generated during the build process.

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 made a number of changes, including releasing version 180), version 181) and version 182) as well as the following changes:
  • New features:
    • Add support for extracting the signing block from Android APKs. [ ]
    • If we specify a suffix for a temporary file or directory within the code, ensure it starts with an underscore (ie. _ ) to make the generated filenames more human-readable. [ ]
    • Don t include short GCC lines that differ on a single prefix byte either. These are distracting, not very useful and are simply the strings(1) command s idea of the build ID, which is displayed elsewhere in the diff. [ ][ ]
    • Don t include specific .debug-like lines in the ELF-related output, as it is invariably a duplicate of the debug ID that exists better in the readelf(1) differences for this file. [ ]
  • Bug fixes:
    • Add a special case to SquashFS image extraction to not fail if we aren t the superuser. [ ]
    • Only use java -jar /path/to/apksigner.jar if we have an apksigner.jar as newer versions of apksigner in Debian use a shell wrapper script which will be rejected if passed directly to the JVM. [ ]
    • Reduce the maximum line length for calculating Wagner-Fischer, improving the speed of output generation a lot. [ ]
    • Don t require apksigner in order to compare .apk files using apktool. [ ]
    • Update calls (and tests) for the new version of odt2txt. [ ]
  • Output improvements:
    • Mention in the output if the apksigner tool is missing. [ ]
    • Profile diffoscope.diff.linediff and specialize. [ ][ ]
  • Logging improvements:
    • Format debug-level messages related to ELF sections using the diffoscope.utils.format_class. [ ]
    • Print the size of generated reports in the logs (if possible). [ ]
    • Include profiling information in --debug output if --profile is not set. [ ]
  • Codebase improvements:
    • Clarify a comment about the HUGE_TOOLS Python dictionary. [ ]
    • We can pass -f to apktool to avoid creating a strangely-named subdirectory. [ ]
    • Drop an unused File import. [ ]
    • Update the supported & minimum version of Black. [ ]
    • We don t use the logging variable in a specific place, so alias it to an underscore (ie. _ ) instead. [ ]
    • Update some various copyright years. [ ]
    • Clarify a comment. [ ]
  • Test improvements:
    • Update a test to check specific contents of SquashFS listings, otherwise it fails depending on the test systems user ID to username passwd(5) mapping. [ ]
    • Assign seen and expected values to local variables to improve contextual information in failed tests. [ ]
    • Don t print an orphan newline when the source code formatting test passes. [ ]

In addition Santiago Torres Arias added support for Squashfs version 4.5 [ ] and Felix C. Stegerman suggested a number of small improvements to the output of the new APK signing block [ ]. Lastly, Chris Lamb uploaded python-libarchive-c version 3.1-1 to Debian experimental for the new 3.x branch python-libarchive-c is used by diffoscope.

Distribution work In Debian, 68 reviews of packages were added, 33 were updated and 10 were removed this month, adding to our knowledge about identified issues. Two new issue types have been identified too: nondeterministic_ordering_in_todo_items_collected_by_doxygen and kodi_package_captures_build_path_in_source_filename_hash. kpcyrd published another monthly report on their work on reproducible builds within the Alpine and Arch Linux distributions, specifically mentioning rebuilderd, one of the components powering reproducible.archlinux.org. The report also touches on binary transparency, an important component for supply chain security. The @GuixHPC account on Twitter posted an infographic on what fraction of GNU Guix packages are bit-for-bit reproducible: Finally, Bernhard M. Wiedemann posted his monthly reproducible builds status report for openSUSE.

Upstream patches The Reproducible Builds project detects, dissects and attempts to fix as many currently-unreproducible packages as possible. We endeavour to send all of our patches upstream where appropriate. This month, we wrote a large number of such patches, including: Elsewhere, it was discovered that when supporting various new language features and APIs for Android apps, the resulting APK files that are generated now vary wildly from build to build (example diffoscope output). Happily, it appears that a patch has been committed to the relevant source tree. This was also discussed on our mailing list this month in a thread titled Android desugaring and reproducible builds started by Marcus Hoffmann.

Website and documentation There were quite a few changes to the Reproducible Builds website and documentation this month, including:
  • Felix C. Stegerman:
    • Update the website self-build process to not use the buster-backports suite now that Debian Bullseye is the stable release. [ ]
  • Holger Levsen:
    • Add a new page documenting various package rebuilder solutions. [ ]
    • Add some historical talks and slides from DebConf20. [ ][ ]
    • Various improvements to the history page. [ ][ ][ ]
    • Rename the Comparison protocol documentation category to Verification . [ ]
    • Update links to F-Droid documentation. [ ]
  • Ian Muchina:
    • Increase the font size of titles and de-emphasize event details on the talk page. [ ]
    • Rename the README file to README.md to improve the user experience when browsing the Git repository in a web browser. [ ]
  • Mattia Rizzolo:
    • Drop a position:fixed CSS statement that is negatively affecting with some width settings. [ ]
    • Fix the sizing of the elements inside the side navigation bar. [ ]
    • Show gold level sponsors and above in the sidebar. [ ]
    • Updated the documentation within reprotest to mention how ldconfig conflicts with the kernel variation. [ ]
  • Roland Clobus:
    • Added a ticket number for the issue with the live Cinnamon image and diffoscope. [ ]

Testing framework The Reproducible Builds project runs a testing framework at tests.reproducible-builds.org, to check packages and other artifacts for reproducibility. This month, the following changes were made:
  • Holger Levsen:
    • Debian-related changes:
      • Make a large number of changes to support the new Debian bookworm release, including adding it to the dashboard [ ], start scheduling tests [ ], adding suitable Apache redirects [ ] etc. [ ][ ][ ][ ][ ]
      • Make the first build use LANG=C.UTF-8 to match the official Debian build servers. [ ]
      • Only test Debian Live images once a week. [ ]
      • Upgrade all nodes to use Debian Bullseye [ ] [ ]
      • Update README documentation for the Debian Bullseye release. [ ]
    • Other changes:
      • Only include rsync output if the $DEBUG variable is enabled. [ ]
      • Don t try to install mock, a tool used to build Fedora packages some time ago. [ ]
      • Drop an unused function. [ ]
      • Various documentation improvements. [ ][ ]
      • Improve the node health check to detect zombie jobs. [ ]
  • Jessica Clarke (FreeBSD-related changes):
    • Update the location and branch name for the main FreeBSD Git repository. [ ]
    • Correctly ignore the source tarball when comparing build results. [ ]
    • Drop an outdated version number from the documentation. [ ]
  • Mattia Rizzolo:
    • Block F-Droid jobs from running whilst the setup is running. [ ]
    • Enable debugging for the rsync job related to Debian Live images. [ ]
    • Pass BUILD_TAG and BUILD_URL environment for the Debian Live jobs. [ ]
    • Refactor the master_wrapper script to use a Bash array for the parameters. [ ]
    • Prefer YAML s safe_load() function over the unsafe variant. [ ]
    • Use the correct variable in the Apache config to match possible existing files on disk. [ ]
    • Stop issuing HTTP 301 redirects for things that not actually permanent. [ ]
  • Roland Clobus (Debian live image generation):
    • Increase the diffoscope timeout from 120 to 240 minutes; the Cinnamon image should now be able to finish. [ ]
    • Use the new snapshot service. [ ]
    • Make a number of improvements to artifact handling, such as moving the artifacts to the Jenkins host [ ] and correctly cleaning them up at the right time. [ ][ ][ ]
    • Where possible, link to the Jenkins build URL that created the artifacts. [ ][ ]
    • Only allow only one job to run at the same time. [ ]
  • Vagrant Cascadian:
    • Temporarily disable armhf nodes for DebConf21. [ ][ ]

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

31 July 2021

Chris Lamb: Free software activities in July 2021

Here is my monthly update covering what I have been doing in the free software world during July 2021 (previous month): As part of my role of being the assistant Secretary of the Open Source Initiative and a board director of Software in the Public Interest I attended their respective monthly meetings. As outlined in last months posts, however, my term on the OSI board has been slightly extended due to the discovery of a vulnerability in OSI's recent election as a result, the 2021 election is currently being re-run. Reproducible Builds One of the original promises of open source software is that distributed peer review and transparency of process results in enhanced end-user security. However, whilst anyone may inspect the source code of free and open source software for malicious flaws, almost all software today is distributed as pre-compiled binaries. This allows nefarious third parties to compromise systems by injecting malicious code into ostensibly secure software during the various compilation and distribution processes. 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. This month, I: I also made the following changes to diffoscope, including preparing and uploading versions 178 and 179 to PyPI and Debian: Debian Bugs filed Uploads Debian LTS This month I have worked 18 hours on Debian Long Term Support (LTS) and 12 hours on its sister Extended LTS project. You can find out more about the project via the following video:

1 July 2021

Vincent Bernat: Upgrading my desktop PC

I built my current desktop PC in 2014. A second SSD was added in 2015. The motherboard and the power supply were replaced after a fault1 in 2016. The memory was upgraded in 2018. A discrete AMD GPU was installed in 2019 to drive two 4K screens. An NVMe disk was added earlier this year to further increase storage performance. This is a testament to the durability of a desktop PC compared to a laptop: it s evolutive and you can keep it a long time. While fine for most usage, the CPU started to become a bottleneck during video conferences.2 So, it was set for an upgrade. The table below summarizes the change. This update cost me about 800 .
Before After
CPU Intel i5-4670K @ 3.4 GHz AMD Ryzen 5 5600X @ 3.7 GHz
CPU fan Zalman CNPS9900 Noctua NH-U12S
Motherboard Asus Z97-PRO Gamer Asus TUF Gaming B550-PLUS
RAM 2 8 GB + 2 4 GB DDR3 @ 1.6 GHz 2 16 GB DDR4 @ 3.6 GHz
GPU Asus Radeon PH RX 550 4G M7
Disks 500 GB Crucial P2 NVMe
256 GB Samsung SSD 850
256 GB Samsung SSD 840
PSU be quiet! Pure Power CM L8 @ 530 W
Case Antec P100
According to some benchmark, the new CPU should be 4 faster when all cores are used and 1.5 faster for a single-threaded workload. Compiling an arbitrary3 kernel provides a 3 speedup. Before:
$ lscpu -e
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE    MAXMHZ   MINMHZ
  0    0      0    0 0:0:0:0          yes 3800.0000 800.0000
  1    0      0    1 1:1:1:0          yes 3800.0000 800.0000
  2    0      0    2 2:2:2:0          yes 3800.0000 800.0000
  3    0      0    3 3:3:3:0          yes 3800.0000 800.0000
$ CCACHE_DISABLE=1 =time -f '  %E' make -j$(nproc)
[ ]
  OBJCOPY arch/x86/boot/vmlinux.bin
  AS      arch/x86/boot/header.o
  LD      arch/x86/boot/setup.elf
  OBJCOPY arch/x86/boot/setup.bin
  BUILD   arch/x86/boot/bzImage
Kernel: arch/x86/boot/bzImage is ready  (#1)
  4:54.32
After:
$ lscpu -e
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE    MAXMHZ    MINMHZ
  0    0      0    0 0:0:0:0          yes 5210.3511 2200.0000
  1    0      0    1 1:1:1:0          yes 4650.2920 2200.0000
  2    0      0    2 2:2:2:0          yes 5210.3511 2200.0000
  3    0      0    3 3:3:3:0          yes 5073.0459 2200.0000
  4    0      0    4 4:4:4:0          yes 4932.1279 2200.0000
  5    0      0    5 5:5:5:0          yes 4791.2100 2200.0000
  6    0      0    0 0:0:0:0          yes 5210.3511 2200.0000
  7    0      0    1 1:1:1:0          yes 4650.2920 2200.0000
  8    0      0    2 2:2:2:0          yes 5210.3511 2200.0000
  9    0      0    3 3:3:3:0          yes 5073.0459 2200.0000
 10    0      0    4 4:4:4:0          yes 4932.1279 2200.0000
 11    0      0    5 5:5:5:0          yes 4791.2100 2200.0000
$ CCACHE_DISABLE=1 =time -f '  %E' make -j$(nproc)
[ ]
  OBJCOPY arch/x86/boot/vmlinux.bin
  AS      arch/x86/boot/header.o
  LD      arch/x86/boot/setup.elf
  OBJCOPY arch/x86/boot/setup.bin
  BUILD   arch/x86/boot/bzImage
Kernel: arch/x86/boot/bzImage is ready  (#1)
  1:40.18
Here we go for another seven years!

  1. The original power supply was from an older configuration. It suddenly became unable to reliably start the PC. The motherboard got replaced as it was the first suspect: without load, the power supply was working correctly.
  2. On Linux, many programs are unable to leverage hardware acceleration. This is a pity. On a laptop, this can also draws the battery pretty fast.
  3. The kernel is configured with make defconfig on commit 15fae3410f1d.

18 June 2021

Gunnar Wolf: Fighting spam on roundcube with modsecurity

Every couple of months, one of my users falls prey to phishing attacks, and send their login/password data to an unknown somebody who poses as Well, as me, their always-friendly and always-helpful systems administrator. What follows is, of course, me spending a week trying to get our systems out of all of the RBLs/DNSBLs. But, no matter how fast I act, there s always distruption and lost mails (bounced or classified as spam) for my users. Most of my users use the Webmail I have configured on our institute s servers, Roundcube, for which I have the highest appreciation. Only that Of course, when a user yields their username and password to an attacker, it is very successful at Sending huge amounts of unrequested mail, leading to my server losing its reputation This week, I set two bits of mitigation strategies. The first one, most straightforward, was to ask Roundcube to disallow sending mails with over ten recipients. In a Debian install, this is as easy as setting up the following variable in /etc/roundcube/config.inc.php:
$config['max_recipients'] = 10
However, a dilligent spammer can still clog the server by sending many, many, many, many requests maybe each of them with ten recipients only; last weekend, I got a new mail every three seconds or so. Adding rate limit to a specific Roundcube action is not easy, however, or at least it took me quite a bit of headbanging to get it right . Roundcube is a very AJAX-y system where all (most, at least) actions are received by /index.php and there is quite a bit of parsing to do to understand the actions done. When sending a mail, of course, it is done using the POST HTTP verb, and the URI-specified variables include _task=mail&_unlock=loading<message_id> (of course, with changing message IDs). After some poking here and there, I faced to SpiderLabs ModSecurity Only that I am not yet well versed in writing rules for it. But after quite a bit of reading, poking, breaking I was able to come up with the following rules:
# How often does the limit counter expire   ratelimit_client=60,
# every 60 seconds
SecRule REQUEST_LINE "@rx POST.*_task=mail&_unlock" id:10,phase:2,nolog,pass,setuid:% tx.ua_hash ,setvar:user.ratelimit_client=+1,expirevar:user.ratelimit_client=60
# How many requests do we allow in the specified time period?  
# @gt 3, 3 requests
SecRule user:ratelimit_client "@gt 2" chain,id:100009,phase:2,deny,status:429,setenv:RATELIMITED,log,msg:RATE-LIMITED
SecRule REQUEST_LINE "@rx POST.*_task=mail&_unlock"
The first line specifies the rule will match request lines specifying the POST verb aind including the _task=mail&_unlock fragment in the URL. It increments tht ratelimit_client user variable, but expires it after 60 seconds. The first line verifies whether the above specified variable (do note that it s user: instead of user.) is greater than 2. If so, it sets the deny action, HTTP return status of 429 (Too Many Requests), and logs the reason why this request was denied (rate-limited). And Given the way Roundcube works, this even works transparently! If a user hits the limit, the mail sending component will just wait and, after a while, time out. Then, the user can click Send again. If legitimate users are too productive and try to send over three mails in a minute, they won t lose any of it; spammers will (hopefully!) find it unbearably slow and give up. Logging is quite informative; I will probably later restrict it to show fewer parts (even if just for privacy sake, as it logs the full request!) For a complex permissions framework such as mod_security, having information such as the following is most welcome in order to find a possibly misbehaving rule:
--76659f4b-H--
Message: Access denied with code 429 (phase 2). Pattern match "POST.*_task=mail&_unlock" at REQUEST_LINE. [file "/etc/modsecurity/rate_limit_sender.conf"] [line "20"] [id "100009"] [msg "RATELIMITED BOT"]
Apache-Error: [file "apache2_util.c"] [line 273] [level 3] [client 192.168.1.48] ModSecurity: Access denied with code 429 (phase 2). Pattern match "POST.*_task=mail&_unlock" at REQUEST_LINE. [file "/etc/modsecurity/rate_limit_sender.conf"] [line "20"] [id "100009"] [msg "RATELIMITED BOT"] [hostname "my.server.mx"] [uri "/roundcube/"] [unique_id "YMzJLR9jVDMGsG@18kB1qAAAAAY"]
Action: Intercepted (phase 2)
Stopwatch: 1624033581838813 1204 (- - -)
Stopwatch2: 1624033581838813 1204; combined=352, p1=29, p2=140, p3=0, p4=0, p5=94, sr=81, sw=89, l=0, gc=0
Response-Body-Transformed: Dechunked
Producer: ModSecurity for Apache/2.9.3 (http://www.modsecurity.org/).
Server: Apache
WebApp-Info: "default" "-" ""
Engine-Mode: "ENABLED"
I truly, truly hope this is the last time my server falls in the black pits of DNSBL/RBL lists

16 June 2021

Julien Danjou: Python Tools to Try in 2021

Python Tools to Try in 2021The Python programming language is one of the most popular and in huge demand. It is free, has a large community, is intended for the development of projects of varying complexity, is easy to learn, and opens up great opportunities for programmers. To work comfortably with it, you need special Python tools, which are able to simplify your work. We have selected the best Python tools that will be relevant in 2021.

MailtrapAs you may probably know, in order to send an email, you need SMTP (Simple Mail Transfer Protocol). This is because you can't just send a letter to the recipient. It needs to be sent to the server from which the recipient will download this letter using IMAP and POP3.Mailtrap provides an opportunity to send emails in python. Moreover, Mailtrap provides #rest #api to access current emails. It can be used to automate email testing, which will improve your email marketing campaigns. For example, you can check the password recovery form in the Selenium Test and immediately see if an email was sent to the correct address. Then take a new password from the email and try to enter the site with it. Cool, isn't it?

Pros
  • All emails are in one place.
  • Mailtrap provides multiple inboxes.
  • Shared access is present.
  • It is easy to set up.
  • RESTful API

ConsNo visible disadvantages were found.

Django
Python Tools to Try in 2021
Django is a free and open-source full-stack framework. It is one of the most important and popular among Python developers. It helps you move from a prototype to a ready-made working solution in a short time since its main task is to automate processes and speed up work through associations and libraries. It s a great choice for a product launch.You can use Django if at least a few of the following points interest you:
  • There is a need to develop the server-side of the API.
  • You need to develop a web application.
  • In the course of work, many changes are made, you have to constantly deploy the application and make edits.
  • There are many complex tasks that are difficult to solve on your own, and you will need the help of the community.
  • ORM support is needed to avoid accessing the database directly.
  • There is a need to integrate new technologies such as machine learning.
Django is a great Python Web Framework that does its job. It is not for nothing that it is one of the most popular, and is actively used by millions of developers.

ProsDjango has quite a few advantages. It contains a large number of ready-made solutions, which greatly simplifies development. Admin panel, database migration, various forms, user authentication tools are extremely helpful. The structure is very clear and simple.A large community helps to solve almost any problem. Thanks to ORM, there is a high level of security and it is comfortable to work with databases.

ConsDespite its powerful capabilities, Django's Python Web Framework has drawbacks. It is very massive, monolithic, therefore it develops slowly. Despite the many generic modules, the development speed of Django itself is reduced.

CherryPy
Python Tools to Try in 2021
CherryPy is a micro-framework. It is designed to solve specific problems, capable of running the program on any operating system. CherryPy is used in the following cases:
  • To create an application with small code size.
  • There is a need to manage several servers at the same time.
  • You need to monitor the performance of applications.
CherryPy refers to Python Frameworks, which are designed for specific tasks. It's clear, user-friendly, and ideal for Android development.

ProsCherryPy Python tool has a friendly and understandable development environment. This is a functional and complete framework, which can be used to build good applications. The source code is open, so the platform is completely free for developers, and the community, although not too large, is very responsive, and always helps to solve problems.

ConsThere are not so many cons to this Python tool. It is not capable of performing complex tasks and functions, it is intended more for specific solutions, for example, for the development of certain plugins or modules.

Pyramid
Python Tools to Try in 2021
Python Pyramid tool is designed for programming complex objects and solving multifunctional problems. It is used by professional programmers and is traditionally used for identification and routing. It is aimed at a wide audience and is capable of developing API prototypes.It is used in the following cases:
  • You need problem indicator tools to make timely adjustments and edits.
  • You use several programming languages at once;
  • You work with reporting and financial calculations, forecasting;
  • You need to quickly create a simple application.
At the same time, the Python Web Framework Pyramid allows you to create complex applications with great functionality like a translation software.

ProsPyramid does an excellent job of developing basic applications quickly. It is quite flexible and easy to learn. In fact, the key to the success of this framework is that it is completely based on fundamental principles, using simple and basic programming techniques. It is minimalistic, but at the same time offers users a lot of freedom of action. It is able to work with both small applications and powerful multifunctional programs.

ConsIt is difficult to deviate from the basic principles. This Python tool makes the decision for you. Simple programs are very easy to implement. But to do something complex and large-scale, you have to completely immerse yourself in the study of the environment and obey it.

Grok
Python Tools to Try in 2021
Grok is a Python tool that works with templates. Its main task is to eliminate repetitions in the code. If the element is repeated, then the template that was already created earlier is simply applied. This greatly simplifies and speeds up the work.Grok suits developers in the following cases:
  • If a programmer has little experience and is not yet ready to develop his modules.
  • There is a need to quickly develop a simple application.
  • The functionality of the application is simple, straightforward, and the interface does not play a key role.

ProsThe Grok framework is a child of Zope3, which was released earlier. It has a simplified structure of work, easy installation of modules, more capabilities, and better flexibility. It is designed to develop small applications. Yes, it is not intended for complex work, but due to its functionality, it allows you to quickly implement a project.

ConsThe Grok community is not very large, as this Python tool has not gained widespread popularity. Nevertheless, it is used by Python adepts for comfortable development. It is impossible to implement complex tasks on it since the possibilities are quite limited.Grok is one of the best Python Web Frameworks. It is understandable and has enough features for comfortable development.

Web2Py
Python Tools to Try in 2021
Web2Py is a Python tool that has its own IDEwhich, which includes a code editor, debugger, and deployment. It works great without the need for configuration or installation, provides a high level of data security, and is suitable for work on various platforms.Web2Py is great in the following cases:
  • When there is a need to develop something on different operating systems.
  • If there is no way to install and configure the framework.
  • When a high level of data security is required, for example, when developing financial applications or sales performance management tools.
  • If you need to carefully track bugs right during development, and not during the testing phase.

ProsWeb2Py is capable of working with different protocols, has a built-in error tracker, and has a backward compatibility feature that helps to work on the basis of previous versions of the framework. This means that code maintenance becomes much easier and cheaper. It's free, open-source, and very flexible.

ConsAmong the many Python tools, there are not many that require the latest version of the language. Web2Py is one of those and won't work on Python 3 and below. Therefore, you need to constantly monitor the updates.Web2Py does an excellent job of its tasks. It is quite simple and accessible to everyone.

BlueBream
Python Tools to Try in 2021
BlueBream used to be called Zope3 before. It copes well with tasks of the medium and high level of complexity and is suitable for working on serious projects.

ProsThe BlueBream build system is quite powerful and suitable for complex tasks. You can create functional applications on it, and the principle of reuse of components makes the code easier. At the same time, the speed of development increases. The software can be scaled, and a transactional object database provides an easy path to store it. This means that queries are processed quickly and database management is simple.

ConsThis is not a very flexible framework, it is better to know clearly in advance what is required of it. In addition, it cannot withstand heavy loads. When working with 1000 users at the same time, it can crash and give errors. Therefore, it should be used to solve narrow problems.Python frameworks are often designed for specific tasks. BlueBream is one of these and is suitable for applications where database management plays a key role.

ConclusionPython tools come in different forms and have vastly different capabilities. There are quite a few of them, but in 2021 these will be the most popular and in demand. Experienced programmers always choose several development tools for their comfortable work.

14 June 2021

Fran ois Marier: Self-hosting an Ikiwiki blog

8.5 years ago, I moved my blog to Ikiwiki and Branchable. It's now time for me to take the next step and host my blog on my own server. This is how I migrated from Branchable to my own Apache server.

Installing Ikiwiki dependencies Here are all of the extra Debian packages I had to install on my server:
apt install ikiwiki ikiwiki-hosting-common gcc libauthen-passphrase-perl libcgi-formbuilder-perl libcrypt-sslauthen-passphrase-perl libcgi-formbuilder-perl libcrypt-ssleay-perl libjson-xs-perl librpc-xml-perl python-docutils libxml-feed-perl libsearch-xapian-perl libmailtools-perl highlight-common libsearch-xapian-perl xapian-omega
apt install --no-install-recommends ikiwiki-hosting-web libgravatar-url-perl libmail-sendmail-perl libcgi-session-perl
apt purge libnet-openid-consumer-perl
Then I enabled the CGI module in Apache:
a2enmod cgi
and un-commented the following in /etc/apache2/mods-available/mime.conf:
AddHandler cgi-script .cgi

Creating a separate user account Since Ikiwiki needs to regenerate my blog whenever a new article is pushed to the git repo or a comment is accepted, I created a restricted user account for it:
adduser blog
adduser blog sshuser
chsh -s /usr/bin/git-shell blog

git setup Thanks to Branchable storing blogs in git repositories, I was able to import my blog using a simple git clone in /home/blog (the srcdir):
git clone --bare git://feedingthecloud.branchable.com/ source.git
Note that the name of the directory (source.git) is important for the ikiwikihosting plugin to work. Then I pulled the .setup file out of the setup branch in that repo and put it in /home/blog/.ikiwiki/FeedingTheCloud.setup. After that, I deleted the setup branch and the origin remote from that clone:
git branch -d setup
git remote rm origin
Following the recommended git configuration, I created a working directory (the repository) for the blog user to modify the blog as needed:
cd /home/blog/
git clone /home/blog/source.git FeedingTheCloud
I added my own ssh public key to /home/blog/.ssh/authorized_keys so that I could push to the srcdir from my laptop. Finaly, I generated a new ssh key without a passphrase:
ssh-keygen -t ed25519
and added it as deploy key to the GitHub repo which acts as a read-only mirror of my blog.

Ikiwiki config While I started with the Branchable setup file, I changed the following things in it:
adminemail: webmaster@fmarier.org
srcdir: /home/blog/FeedingTheCloud
destdir: /var/www/blog
url: https://feeding.cloud.geek.nz
cgiurl: https://feeding.cloud.geek.nz/blog.cgi
cgi_wrapper: /var/www/blog/blog.cgi
cgi_wrappermode: 675
add_plugins:
- goodstuff
- lockedit
- comments
- blogspam
- sidebar
- attachment
- favicon
- format
- highlight
- search
- theme
- moderatedcomments
- flattr
- calendar
- headinganchors
- notifyemail
- anonok
- autoindex
- date
- relativedate
- htmlbalance
- pagestats
- sortnaturally
- ikiwikihosting
- gitpush
- emailauth
disable_plugins:
- brokenlinks
- fortune
- more
- openid
- orphans
- passwordauth
- progress
- recentchanges
- repolist
- toggle
- txt
sslcookie: 1
cookiejar:
  file: /home/blog/.ikiwiki/cookies
useragent: ikiwiki
git_wrapper: /home/blog/source.git/hooks/post-update
urlalias:
- http://feeds.cloud.geek.nz/
- http://www.feeding.cloud.geek.nz/
owner: francois@fmarier.org
hostname: feeding.cloud.geek.nz
emailauth_sender: login@fmarier.org
allowed_attachments: admin()
Then I created the destdir:
mkdir /var/www/blog
chown blog:blog /var/www/blog
and generated the initial copy of the blog as the blog user:
ikiwiki --setup .ikiwiki/FeedingTheCloud.setup --wrappers --rebuild
One thing that failed to generate properly was the tag cloug (from the pagestats plugin). I have not been able to figure out why it fails to generate any output when run this way, but if I push to the repo and let the git hook handle the rebuilding of the wiki, the tag cloud is generated correctly. Consequently, fixing this is not high on my list of priorities, but if you happen to know what the problem is, please reach out.

Apache config Here's the Apache config I put in /etc/apache2/sites-available/blog.conf:
<VirtualHost *:443>
    ServerName feeding.cloud.geek.nz
    SSLEngine On
    SSLCertificateFile /etc/letsencrypt/live/feeding.cloud.geek.nz/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/feeding.cloud.geek.nz/privkey.pem
    Header set Strict-Transport-Security: "max-age=63072000; includeSubDomains; preload"
    Include /etc/fmarier-org/blog-common
</VirtualHost>
<VirtualHost *:443>
    ServerName www.feeding.cloud.geek.nz
    ServerAlias feeds.cloud.geek.nz
    SSLEngine On
    SSLCertificateFile /etc/letsencrypt/live/feeding.cloud.geek.nz/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/feeding.cloud.geek.nz/privkey.pem
    Redirect permanent / https://feeding.cloud.geek.nz/
</VirtualHost>
<VirtualHost *:80>
    ServerName feeding.cloud.geek.nz
    ServerAlias www.feeding.cloud.geek.nz
    ServerAlias feeds.cloud.geek.nz
    Redirect permanent / https://feeding.cloud.geek.nz/
</VirtualHost>
and the common config I put in /etc/fmarier-org/blog-common:
ServerAdmin webmaster@fmarier.org
DocumentRoot /var/www/blog
LogLevel core:info
CustomLog $ APACHE_LOG_DIR /blog-access.log combined
ErrorLog $ APACHE_LOG_DIR /blog-error.log
AddType application/rss+xml .rss
<Location /blog.cgi>
        Options +ExecCGI
</Location>
before enabling all of this using:
a2ensite blog
apache2ctl configtest
systemctl restart apache2.service
The feeds.cloud.geek.nz domain used to be pointing to Feedburner and so I need to maintain it in order to avoid breaking RSS feeds from folks who added my blog to their reader a long time ago.

Server-side improvements Since I'm now in control of the server configuration, I was able to make several improvements to how my blog is served. First of all, I enabled the HTTP/2 and Brotli modules:
a2enmod http2
a2enmod brotli
and enabled Brotli compression by putting the following in /etc/apache2/conf-available/compression.conf:
<IfModule mod_brotli.c>
  <IfDefine !TRANSFER_COMPRESSION>
    Define TRANSFER_COMPRESSION BROTLI_COMPRESS
  </IfDefine>
</IfModule>
<IfModule mod_deflate.c>
  <IfDefine !TRANSFER_COMPRESSION>
    Define TRANSFER_COMPRESSION DEFLATE
  </IfDefine>
</IfModule>
<IfDefine TRANSFER_COMPRESSION>
  <IfModule mod_filter.c>
    AddOutputFilterByType $ TRANSFER_COMPRESSION  text/html text/plain text/xml text/css text/javascript
    AddOutputFilterByType $ TRANSFER_COMPRESSION  application/x-javascript application/javascript application/ecmascript
    AddOutputFilterByType $ TRANSFER_COMPRESSION  application/rss+xml
    AddOutputFilterByType $ TRANSFER_COMPRESSION  application/xml
  </IfModule>
</IfDefine>
and replacing /etc/apache2/mods-available/deflate.conf with the following:
# Moved to /etc/apache2/conf-available/compression.conf as per https://bugs.debian.org/972632
before enabling this new config:
a2enconf compression
Next, I made my blog available as a Tor onion service by putting the following in /etc/apache2/sites-available/blog.conf:
<VirtualHost *:443>
    ServerName feeding.cloud.geek.nz
    ServerAlias xfdug5vmfi6oh42fp6ahhrqdjcf7ysqat6fkp5dhvde4d7vlkqixrsad.onion
    Header set Onion-Location "http://xfdug5vmfi6oh42fp6ahhrqdjcf7ysqat6fkp5dhvde4d7vlkqixrsad.onion% REQUEST_URI s"
    Header set alt-svc 'h2="xfdug5vmfi6oh42fp6ahhrqdjcf7ysqat6fkp5dhvde4d7vlkqixrsad.onion:443"; ma=315360000; persist=1'
    ... 
<VirtualHost *:80>
    ServerName xfdug5vmfi6oh42fp6ahhrqdjcf7ysqat6fkp5dhvde4d7vlkqixrsad.onion
    Include /etc/fmarier-org/blog-common
</VirtualHost>
Then I followed the Mozilla Observatory recommendations and enabled the following security headers:
Header set Content-Security-Policy: "default-src 'none'; report-uri https://fmarier.report-uri.com/r/d/csp/enforce ; style-src 'self' 'unsafe-inline' ; img-src 'self' https://seccdn.libravatar.org/ ; script-src https://feeding.cloud.geek.nz/ikiwiki/ https://xfdug5vmfi6oh42fp6ahhrqdjcf7ysqat6fkp5dhvde4d7vlkqixrsad.onion/ikiwiki/ http://xfdug5vmfi6oh42fp6ahhrqdjcf7ysqat6fkp5dhvde4d7vlkqixrsad.onion/ikiwiki/ 'unsafe-inline' 'sha256-pA8FbKo4pYLWPDH2YMPqcPMBzbjH/RYj0HlNAHYoYT0=' 'sha256-Kn5E/7OLXYSq+EKMhEBGJMyU6bREA9E8Av9FjqbpGKk=' 'sha256-/BTNlczeBxXOoPvhwvE1ftmxwg9z+WIBJtpk3qe7Pqo=' ; base-uri 'self'; form-action 'self' ; frame-ancestors 'self'"
Header set X-Frame-Options: "SAMEORIGIN"
Header set Referrer-Policy: "same-origin"
Header set X-Content-Type-Options: "nosniff"
Note that the Mozilla Observatory is mistakenly identifying HTTP onion services as insecure, so you can ignore that failure. I also used the Mozilla TLS config generator to improve the TLS config for my server. Then I added security.txt and gpc.json to the root of my git repo and then added the following aliases to put these files in the right place:
Alias /.well-known/gpc.json /var/www/blog/gpc.json
Alias /.well-known/security.txt /var/www/blog/security.txt
I also followed these instructions to create a sitemap for my blog with the following alias:
Alias /sitemap.xml /var/www/blog/sitemap/index.rss
Finally, I simplified a few error pages to save bandwidth:
ErrorDocument 301 " "
ErrorDocument 302 " "
ErrorDocument 404 "Not Found"

Monitoring 404s Another advantage of running my own web server is that I can monitor the 404s easily using logcheck by putting the following in /etc/logcheck/logcheck.logfiles:
/var/log/apache2/blog-error.log 
Based on that, I added a few redirects to point bots and users to the location of my RSS feed:
Redirect permanent /atom /index.atom
Redirect permanent /comments.rss /comments/index.rss
Redirect permanent /comments.atom /comments/index.atom
Redirect permanent /FeedingTheCloud /index.rss
Redirect permanent /feed /index.rss
Redirect permanent /feed/ /index.rss
Redirect permanent /feeds/posts/default /index.rss
Redirect permanent /rss /index.rss
Redirect permanent /rss/ /index.rss
and to tell them to stop trying to fetch obsolete resources:
Redirect gone /~ff/FeedingTheCloud
Redirect gone /gittip_button.png
Redirect gone /ikiwiki.cgi
I also used these 404s to discover a few old Feedburner URLs that I could redirect to the right place using archive.org:
Redirect permanent /feeds/1572545745827565861/comments/default /posts/watch-all-of-your-logs-using-monkeytail/comments.atom
Redirect permanent /feeds/1582328597404141220/comments/default /posts/news-feeds-rssatom-for-mythtvorg-and/comments.atom
...
Redirect permanent /feeds/8490436852808833136/comments/default /posts/recovering-lost-git-commits/comments.atom
Redirect permanent /feeds/963415010433858516/comments/default /posts/debugging-openwrt-routers-by-shipping/comments.atom
I also put the following robots.txt in the git repo in order to stop a bunch of authentication errors coming from crawlers:
User-agent: *
Disallow: /blog.cgi
Disallow: /ikiwiki.cgi

Future improvements There are a few things I'd like to improve on my current setup. The first one is to remove the iwikihosting and gitpush plugins and replace them with a small script which would simply git push to the read-only GitHub mirror. Then I could uninstall the ikiwiki-hosting-common and ikiwiki-hosting-web since that's all I use them for. Next, I would like to have proper support for signed git pushes. At the moment, I have the following in /home/blog/source.git/config:
[receive]
    advertisePushOptions = true
    certNonceSeed = "(random string)"
but I'd like to also reject unsigned pushes. While my blog now has a CSP policy which doesn't rely on unsafe-inline for scripts, it does rely on unsafe-inline for stylesheets. I tried to remove this but the actual calls to allow seemed to be located deep within jQuery and so I gave up. Update: now fixed. Finally, I'd like to figure out a good way to deal with articles which don't currently have comments. At the moment, if you try to subscribe to their comment feed, it returns a 404. For example:
[Sun Jun 06 17:43:12.336350 2021] [core:info] [pid 30591:tid 140253834704640] [client 66.249.66.70:57381] AH00128: File does not exist: /var/www/blog/posts/using-iptables-with-network-manager/comments.atom
This is obviously not ideal since many feed readers will refuse to add a feed which is currently not found even though it could become real in the future. If you know of a way to fix this, please let me know.

5 June 2021

Utkarsh Gupta: FOSS Activites in May 2021

Here s my (twentieth) monthly update about the activities I ve done in the F/L/OSS world.

Debian
This was my 29th month of actively contributing to Debian. I became a DM in late March 2019 and a DD on Christmas 19! \o/ Interesting month, surprisingly. Lots of things happening and lots of moving parts; becoming the new normal , I believe. Anyhow, working on Ubuntu full-time has its own advantage and one of them is being able to work on Debian stuff! So whilst I couldn t upload a lot of packages because of the freeze, here s what I worked on:

Uploads and bug fixes:

Other $things:
  • Mentoring for newcomers and assisting people in BSP.
  • Moderation of -project mailing list.

Ubuntu
This was my 4th month of actively contributing to Ubuntu. Now that I ve joined Canonical to work on Ubuntu full-time, there s a bunch of things I do! \o/ This month, by all means, was dedicated mostly to PHP 8.0, transitioning from PHP 7.4 to 8.0. Naturally, it had so many moving parts and moments of utmost frustration, shared w/ Bryce. :D So even though I can t upload anything, I worked on the following stuff & asked for sponsorship.
But before, I d like to take a moment to stress how kind and awesome Gianfranco Costamagna, a.k.a. LocutusOfBorg is! He s been sponsoring a bunch of my things & helping with re-triggers, et al. Thanks a bunch, Gianfranco; beers on me whenever we meet!

Merges:

Uploads & Syncs:

MIRs:

Seed Operations:

Debian (E)LTS
Debian Long Term Support (LTS) is a project to extend the lifetime of all Debian stable releases to (at least) 5 years. Debian LTS is not handled by the Debian security team, but by a separate group of volunteers and companies interested in making it a success. And Debian Extended LTS (ELTS) is its sister project, extending support to the Jessie release (+2 years after LTS support). This was my twentieth month as a Debian LTS and eleventh month as a Debian ELTS paid contributor.
I was assigned 29.75 hours for LTS and 40.00 hours for ELTS and worked on the following things:

LTS CVE Fixes and Announcements:

ELTS CVE Fixes and Announcements:

Other (E)LTS Work:
  • Front-desk duty from 24-05 until 30-05 for both LTS and ELTS.
  • Triaged rails, libimage-exiftool-perl, hivex, graphviz, glibc, libexosip2, impacket, node-ws, thunar, libgrss, nginx, postgresql-9.6, ffmpeg, composter, and curl.
  • Mark CVE-2019-9904/graphviz as ignored for stretch and jessie.
  • Mark CVE-2021-32029/postgresql-9.6 as not-affected for stretch.
  • Mark CVE-2020-24020/ffmpeg as not-affected for stretch.
  • Mark CVE-2020-22020/ffmpeg as postponed for stretch.
  • Mark CVE-2020-22015/ffmpeg as ignored for stretch.
  • Mark CVE-2020-21041/ffmpeg as postponed for stretch.
  • Mark CVE-2021-33574/glibc as no-dsa for stretch & jessie.
  • Mark CVE-2021-31800/impacket as no-dsa for stretch.
  • Mark CVE-2021-32611/libexosip2 as no-dsa for stretch.
  • Mark CVE-2016-20011/libgrss as ignored for stretch.
  • Mark CVE-2021-32640/node-ws as no-dsa for stretch.
  • Mark CVE-2021-32563/thunar as no-dsa for stretch.
  • [LTS] Help test and review bind9 update for Emilio.
  • [LTS] Suggest and add DEP8 tests for bind9 for stretch.
  • [LTS] Sponsored upload of htmldoc to buster for Havard as a consequence of #988289.
  • [ELTS] Fix triage order for jetty and graphviz.
  • [ELTS] Raise issue upstream about cloud-init; mock tests instead.
  • [ELTS] Write to private ELTS list about triage ordering.
  • [ELTS] Review Emilio s new script and write back feedback, mentioning extra file created, et al.
  • [ELTS/LTS] Raise upgrade problems from LTS -> LTS+1 to the list. Thread here.
    • Further help review and raise problems that could occur, et al.
  • [LTS] Help explain path forward for firmware-nonfree update to Ola. Thread here.
  • [ELTS] Revert entries of TEMP-0000000-16B7E7 and TEMP-0000000-1C4729; CVEs assigned & fix ELTS tracker build.
  • Auto EOL ed linux, libgrss, node-ws, and inspircd for jessie.
  • Attended monthly Debian LTS meeting, which didn t happen, heh.
  • Answered questions (& discussions) on IRC (#debian-lts and #debian-elts).
  • General and other discussions on LTS private and public mailing list.

Until next time.
:wq for today.

28 May 2021

Jonathan McDowell: Trying to understand Kubernetes networking

I previously built a single node Kubernetes cluster as a test environment to learn more about it. The first thing I want to try to understand is its networking. In particular the IP addresses that are listed are all 10.* and my host s network is a 192.168/24. I understand each pod gets its own virtual ethernet interface and associated IP address, and these are generally private within the cluster (and firewalled out other than for exposed services). What does that actually look like?
$ ip route
default via 192.168.53.1 dev enx00e04c6851de
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
192.168.0.0/24 dev weave proto kernel scope link src 192.168.0.1
192.168.53.0/24 dev enx00e04c6851de proto kernel scope link src 192.168.53.147
Huh. No sign of any way to get to 10.107.66.138 (the IP my echoserver from the previous post is available on directly from the host). What about network interfaces? (under the cut because it s lengthy)
ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: enx00e04c6851de: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:e0:4c:68:51:de brd ff:ff:ff:ff:ff:ff
    inet 192.168.53.147/24 brd 192.168.53.255 scope global dynamic enx00e04c6851de
       valid_lft 41571sec preferred_lft 41571sec
3: wlp1s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 74:d8:3e:70:3b:18 brd ff:ff:ff:ff:ff:ff
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether 02:42:18:04:9e:08 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
5: datapath: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether d2:5a:fd:c1:56:23 brd ff:ff:ff:ff:ff:ff
7: weave: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue state UP group default qlen 1000
    link/ether 12:82:8f:ed:c7:bf brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/24 brd 192.168.0.255 scope global weave
       valid_lft forever preferred_lft forever
9: vethwe-datapath@vethwe-bridge: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master datapath state UP group default
    link/ether b6:49:88:d6:6d:84 brd ff:ff:ff:ff:ff:ff
10: vethwe-bridge@vethwe-datapath: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether 6e:6c:03:1d:e5:0e brd ff:ff:ff:ff:ff:ff
11: vxlan-6784: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65535 qdisc noqueue master datapath state UNKNOWN group default qlen 1000
    link/ether 9a:af:c5:0a:b3:fd brd ff:ff:ff:ff:ff:ff
13: vethwepl534c0a6@if12: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether 1e:ac:f1:85:61:9a brd ff:ff:ff:ff:ff:ff link-netnsid 0
15: vethwepl9ffd6b6@if14: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether 56:ca:71:2a:ab:39 brd ff:ff:ff:ff:ff:ff link-netnsid 1
17: vethwepl62b369d@if16: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether e2:a0:bb:ee:fc:73 brd ff:ff:ff:ff:ff:ff link-netnsid 2
23: vethwepl6669168@if22: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether f2:e7:e6:95:e0:61 brd ff:ff:ff:ff:ff:ff link-netnsid 3
That looks like a collection of virtual ethernet devices that are being managed by the weave networking plugin, and presumably partnered inside each pod. They re bridged to the weave interface (the master weave bit). Still no clues about the 10.* range. What about ARP?
ip neigh
192.168.53.1 dev enx00e04c6851de lladdr e4:8d:8c:35:98:d5 DELAY
192.168.0.4 dev datapath lladdr da:22:06:96:50:cb STALE
192.168.0.2 dev weave lladdr 66:eb:ce:16:3c:62 REACHABLE
192.168.53.136 dev enx00e04c6851de lladdr 00:e0:4c:39:f2:54 REACHABLE
192.168.0.6 dev weave lladdr 56:a9:f0:d2:9e:f3 STALE
192.168.0.3 dev datapath lladdr f2:42:c9:c3:08:71 STALE
192.168.0.3 dev weave lladdr f2:42:c9:c3:08:71 REACHABLE
192.168.0.2 dev datapath lladdr 66:eb:ce:16:3c:62 STALE
192.168.0.6 dev datapath lladdr 56:a9:f0:d2:9e:f3 STALE
192.168.0.4 dev weave lladdr da:22:06:96:50:cb STALE
192.168.0.5 dev datapath lladdr fe:6f:1b:14:56:5a STALE
192.168.0.5 dev weave lladdr fe:6f:1b:14:56:5a REACHABLE
Nope. That just looks like addresses on the weave managed bridge. Alright. What about firewalling?
nft list ruleset
table ip nat  
	chain DOCKER  
		iifname "docker0" counter packets 0 bytes 0 return
	 
	chain POSTROUTING  
		type nat hook postrouting priority srcnat; policy accept;
		 counter packets 531750 bytes 31913539 jump KUBE-POSTROUTING
		oifname != "docker0" ip saddr 172.17.0.0/16 counter packets 1 bytes 84 masquerade 
		counter packets 525600 bytes 31544134 jump WEAVE
	 
	chain PREROUTING  
		type nat hook prerouting priority dstnat; policy accept;
		 counter packets 180 bytes 12525 jump KUBE-SERVICES
		fib daddr type local counter packets 23 bytes 1380 jump DOCKER
	 
	chain OUTPUT  
		type nat hook output priority -100; policy accept;
		 counter packets 527005 bytes 31628455 jump KUBE-SERVICES
		ip daddr != 127.0.0.0/8 fib daddr type local counter packets 285425 bytes 17125524 jump DOCKER
	 
	chain KUBE-MARK-DROP  
		counter packets 0 bytes 0 meta mark set mark or 0x8000 
	 
	chain KUBE-MARK-MASQ  
		counter packets 0 bytes 0 meta mark set mark or 0x4000 
	 
	chain KUBE-POSTROUTING  
		mark and 0x4000 != 0x4000 counter packets 4622 bytes 277720 return
		counter packets 0 bytes 0 meta mark set mark xor 0x4000 
		 counter packets 0 bytes 0 masquerade 
	 
	chain KUBE-KUBELET-CANARY  
	 
	chain INPUT  
		type nat hook input priority 100; policy accept;
	 
	chain KUBE-PROXY-CANARY  
	 
	chain KUBE-SERVICES  
		meta l4proto tcp ip daddr 10.96.0.10  tcp dport 9153 counter packets 0 bytes 0 jump KUBE-SVC-JD5MR3NA4I4DYORP
		meta l4proto tcp ip daddr 10.107.66.138  tcp dport 8080 counter packets 1 bytes 60 jump KUBE-SVC-666FUMINWJLRRQPD
		meta l4proto tcp ip daddr 10.111.16.129  tcp dport 443 counter packets 0 bytes 0 jump KUBE-SVC-EZYNCFY2F7N6OQA2
		meta l4proto tcp ip daddr 10.96.9.41  tcp dport 443 counter packets 0 bytes 0 jump KUBE-SVC-EDNDUDH2C75GIR6O
		meta l4proto tcp ip daddr 192.168.53.147  tcp dport 443 counter packets 0 bytes 0 jump KUBE-XLB-EDNDUDH2C75GIR6O
		meta l4proto tcp ip daddr 10.96.9.41  tcp dport 80 counter packets 0 bytes 0 jump KUBE-SVC-CG5I4G2RS3ZVWGLK
		meta l4proto tcp ip daddr 192.168.53.147  tcp dport 80 counter packets 0 bytes 0 jump KUBE-XLB-CG5I4G2RS3ZVWGLK
		meta l4proto tcp ip daddr 10.96.0.1  tcp dport 443 counter packets 0 bytes 0 jump KUBE-SVC-NPX46M4PTMTKRN6Y
		meta l4proto udp ip daddr 10.96.0.10  udp dport 53 counter packets 0 bytes 0 jump KUBE-SVC-TCOU7JCQXEZGVUNU
		meta l4proto tcp ip daddr 10.96.0.10  tcp dport 53 counter packets 0 bytes 0 jump KUBE-SVC-ERIFXISQEP7F7OF4
		 fib daddr type local counter packets 3312 bytes 198720 jump KUBE-NODEPORTS
	 
	chain KUBE-NODEPORTS  
		meta l4proto tcp  tcp dport 31529 counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp  tcp dport 31529 counter packets 0 bytes 0 jump KUBE-SVC-666FUMINWJLRRQPD
		meta l4proto tcp ip saddr 127.0.0.0/8  tcp dport 30894 counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp  tcp dport 30894 counter packets 0 bytes 0 jump KUBE-XLB-EDNDUDH2C75GIR6O
		meta l4proto tcp ip saddr 127.0.0.0/8  tcp dport 32740 counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp  tcp dport 32740 counter packets 0 bytes 0 jump KUBE-XLB-CG5I4G2RS3ZVWGLK
	 
	chain KUBE-SVC-NPX46M4PTMTKRN6Y  
		 counter packets 0 bytes 0 jump KUBE-SEP-Y6PHKONXBG3JINP2
	 
	chain KUBE-SEP-Y6PHKONXBG3JINP2  
		ip saddr 192.168.53.147  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.53.147:6443
	 
	chain WEAVE  
		# match-set weaver-no-masq-local dst  counter packets 135966 bytes 8160820 return
		ip saddr 192.168.0.0/24 ip daddr 224.0.0.0/4 counter packets 0 bytes 0 return
		ip saddr != 192.168.0.0/24 ip daddr 192.168.0.0/24 counter packets 0 bytes 0 masquerade 
		ip saddr 192.168.0.0/24 ip daddr != 192.168.0.0/24 counter packets 33 bytes 2941 masquerade 
	 
	chain WEAVE-CANARY  
	 
	chain KUBE-SVC-JD5MR3NA4I4DYORP  
		  counter packets 0 bytes 0 jump KUBE-SEP-6JI23ZDEH4VLR5EN
		 counter packets 0 bytes 0 jump KUBE-SEP-FATPLMAF37ZNQP5P
	 
	chain KUBE-SEP-6JI23ZDEH4VLR5EN  
		ip saddr 192.168.0.2  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.2:9153
	 
	chain KUBE-SVC-TCOU7JCQXEZGVUNU  
		  counter packets 0 bytes 0 jump KUBE-SEP-JTN4UBVS7OG5RONX
		 counter packets 0 bytes 0 jump KUBE-SEP-4TCKAEJ6POVEFPVW
	 
	chain KUBE-SEP-JTN4UBVS7OG5RONX  
		ip saddr 192.168.0.2  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto udp   counter packets 0 bytes 0 dnat to 192.168.0.2:53
	 
	chain KUBE-SVC-ERIFXISQEP7F7OF4  
		  counter packets 0 bytes 0 jump KUBE-SEP-UPZX2EM3TRFH2ASL
		 counter packets 0 bytes 0 jump KUBE-SEP-KPHYKKPVMB473Z76
	 
	chain KUBE-SEP-UPZX2EM3TRFH2ASL  
		ip saddr 192.168.0.2  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.2:53
	 
	chain KUBE-SEP-4TCKAEJ6POVEFPVW  
		ip saddr 192.168.0.3  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto udp   counter packets 0 bytes 0 dnat to 192.168.0.3:53
	 
	chain KUBE-SEP-KPHYKKPVMB473Z76  
		ip saddr 192.168.0.3  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.3:53
	 
	chain KUBE-SEP-FATPLMAF37ZNQP5P  
		ip saddr 192.168.0.3  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.3:9153
	 
	chain KUBE-SVC-666FUMINWJLRRQPD  
		 counter packets 1 bytes 60 jump KUBE-SEP-LYLDBZYLHY4MT3AQ
	 
	chain KUBE-SEP-LYLDBZYLHY4MT3AQ  
		ip saddr 192.168.0.4  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 1 bytes 60 dnat to 192.168.0.4:8080
	 
	chain KUBE-XLB-EDNDUDH2C75GIR6O  
		 fib saddr type local counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		 fib saddr type local counter packets 0 bytes 0 jump KUBE-SVC-EDNDUDH2C75GIR6O
		 counter packets 0 bytes 0 jump KUBE-SEP-BLQHCYCSXY3NRKLC
	 
	chain KUBE-XLB-CG5I4G2RS3ZVWGLK  
		 fib saddr type local counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		 fib saddr type local counter packets 0 bytes 0 jump KUBE-SVC-CG5I4G2RS3ZVWGLK
		 counter packets 0 bytes 0 jump KUBE-SEP-5XVRKWM672JGTWXH
	 
	chain KUBE-SVC-EDNDUDH2C75GIR6O  
		 counter packets 0 bytes 0 jump KUBE-SEP-BLQHCYCSXY3NRKLC
	 
	chain KUBE-SEP-BLQHCYCSXY3NRKLC  
		ip saddr 192.168.0.5  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.5:443
	 
	chain KUBE-SVC-CG5I4G2RS3ZVWGLK  
		 counter packets 0 bytes 0 jump KUBE-SEP-5XVRKWM672JGTWXH
	 
	chain KUBE-SEP-5XVRKWM672JGTWXH  
		ip saddr 192.168.0.5  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.5:80
	 
	chain KUBE-SVC-EZYNCFY2F7N6OQA2  
		 counter packets 0 bytes 0 jump KUBE-SEP-JYW326XAJ4KK7QPG
	 
	chain KUBE-SEP-JYW326XAJ4KK7QPG  
		ip saddr 192.168.0.5  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.5:8443
	 
 
table ip filter  
	chain DOCKER  
	 
	chain DOCKER-ISOLATION-STAGE-1  
		iifname "docker0" oifname != "docker0" counter packets 0 bytes 0 jump DOCKER-ISOLATION-STAGE-2
		counter packets 0 bytes 0 return
	 
	chain DOCKER-ISOLATION-STAGE-2  
		oifname "docker0" counter packets 0 bytes 0 drop
		counter packets 0 bytes 0 return
	 
	chain FORWARD  
		type filter hook forward priority filter; policy drop;
		iifname "weave"  counter packets 213 bytes 54014 jump WEAVE-NPC-EGRESS
		oifname "weave"  counter packets 150 bytes 30038 jump WEAVE-NPC
		oifname "weave" ct state new counter packets 0 bytes 0 log group 86 
		oifname "weave" counter packets 0 bytes 0 drop
		iifname "weave" oifname != "weave" counter packets 33 bytes 2941 accept
		oifname "weave" ct state related,established counter packets 0 bytes 0 accept
		 counter packets 0 bytes 0 jump KUBE-FORWARD
		ct state new  counter packets 0 bytes 0 jump KUBE-SERVICES
		ct state new  counter packets 0 bytes 0 jump KUBE-EXTERNAL-SERVICES
		counter packets 0 bytes 0 jump DOCKER-USER
		counter packets 0 bytes 0 jump DOCKER-ISOLATION-STAGE-1
		oifname "docker0" ct state related,established counter packets 0 bytes 0 accept
		oifname "docker0" counter packets 0 bytes 0 jump DOCKER
		iifname "docker0" oifname != "docker0" counter packets 0 bytes 0 accept
		iifname "docker0" oifname "docker0" counter packets 0 bytes 0 accept
	 
	chain DOCKER-USER  
		counter packets 0 bytes 0 return
	 
	chain KUBE-FIREWALL  
		 mark and 0x8000 == 0x8000 counter packets 0 bytes 0 drop
		ip saddr != 127.0.0.0/8 ip daddr 127.0.0.0/8  ct status dnat counter packets 0 bytes 0 drop
	 
	chain OUTPUT  
		type filter hook output priority filter; policy accept;
		ct state new  counter packets 527014 bytes 31628984 jump KUBE-SERVICES
		counter packets 36324809 bytes 6021214027 jump KUBE-FIREWALL
		meta l4proto != esp  mark and 0x20000 == 0x20000 counter packets 0 bytes 0 drop
	 
	chain INPUT  
		type filter hook input priority filter; policy accept;
		 counter packets 35869492 bytes 5971008896 jump KUBE-NODEPORTS
		ct state new  counter packets 390938 bytes 23457377 jump KUBE-EXTERNAL-SERVICES
		counter packets 36249774 bytes 6030068622 jump KUBE-FIREWALL
		meta l4proto tcp ip daddr 127.0.0.1 tcp dport 6784 fib saddr type != local ct state != related,established  counter packets 0 bytes 0 drop
		iifname "weave" counter packets 907273 bytes 88697229 jump WEAVE-NPC-EGRESS
		counter packets 34809601 bytes 5818213726 jump WEAVE-IPSEC-IN
	 
	chain KUBE-KUBELET-CANARY  
	 
	chain KUBE-PROXY-CANARY  
	 
	chain KUBE-EXTERNAL-SERVICES  
	 
	chain KUBE-NODEPORTS  
		meta l4proto tcp  tcp dport 32196 counter packets 0 bytes 0 accept
		meta l4proto tcp  tcp dport 32196 counter packets 0 bytes 0 accept
	 
	chain KUBE-SERVICES  
	 
	chain KUBE-FORWARD  
		ct state invalid counter packets 0 bytes 0 drop
		 mark and 0x4000 == 0x4000 counter packets 0 bytes 0 accept
		 ct state related,established counter packets 0 bytes 0 accept
		 ct state related,established counter packets 0 bytes 0 accept
	 
	chain WEAVE-NPC-INGRESS  
	 
	chain WEAVE-NPC-DEFAULT  
		# match-set weave-;rGqyMIl1HN^cfDki~Z$3]6!N dst  counter packets 14 bytes 840 accept
		# match-set weave-P.B !ZhkAr5q=XZ?3 tMBA+0 dst  counter packets 0 bytes 0 accept
		# match-set weave-Rzff h:=]JaaJl/G;(XJpGjZ[ dst  counter packets 0 bytes 0 accept
		# match-set weave-]B*(W?)t*z5O17G044[gUo#$l dst  counter packets 0 bytes 0 accept
		# match-set weave-iLgO^ o=U/*%KE[@=W:l~ 9T dst  counter packets 9 bytes 540 accept
	 
	chain WEAVE-NPC  
		ct state related,established counter packets 124 bytes 28478 accept
		ip daddr 224.0.0.0/4 counter packets 0 bytes 0 accept
		# PHYSDEV match --physdev-out vethwe-bridge --physdev-is-bridged counter packets 3 bytes 180 accept
		ct state new counter packets 23 bytes 1380 jump WEAVE-NPC-DEFAULT
		ct state new counter packets 0 bytes 0 jump WEAVE-NPC-INGRESS
	 
	chain WEAVE-NPC-EGRESS-ACCEPT  
		counter packets 48 bytes 3769 meta mark set mark or 0x40000 
	 
	chain WEAVE-NPC-EGRESS-CUSTOM  
	 
	chain WEAVE-NPC-EGRESS-DEFAULT  
		# match-set weave-s_+ChJId4Uy_$ G;WdH ~TK)I src  counter packets 0 bytes 0 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-s_+ChJId4Uy_$ G;WdH ~TK)I src  counter packets 0 bytes 0 return
		# match-set weave-E1ney4o[ojNrLk.6rOHi;7MPE src  counter packets 31 bytes 2749 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-E1ney4o[ojNrLk.6rOHi;7MPE src  counter packets 31 bytes 2749 return
		# match-set weave-41s)5vQ^o/xWGz6a20N:~?# E src  counter packets 0 bytes 0 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-41s)5vQ^o/xWGz6a20N:~?# E src  counter packets 0 bytes 0 return
		# match-set weave-sui%__gZ kX~oZgI_Ttqp=Dp src  counter packets 0 bytes 0 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-sui%__gZ kX~oZgI_Ttqp=Dp src  counter packets 0 bytes 0 return
		# match-set weave-nmMUaDKV*YkQcP5s?Q[R54Ep3 src  counter packets 17 bytes 1020 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-nmMUaDKV*YkQcP5s?Q[R54Ep3 src  counter packets 17 bytes 1020 return
	 
	chain WEAVE-NPC-EGRESS  
		ct state related,established counter packets 907425 bytes 88746642 accept
		# PHYSDEV match --physdev-in vethwe-bridge --physdev-is-bridged counter packets 0 bytes 0 return
		fib daddr type local counter packets 11 bytes 640 return
		ip daddr 224.0.0.0/4 counter packets 0 bytes 0 return
		ct state new counter packets 50 bytes 3961 jump WEAVE-NPC-EGRESS-DEFAULT
		ct state new mark and 0x40000 != 0x40000 counter packets 2 bytes 192 jump WEAVE-NPC-EGRESS-CUSTOM
	 
	chain WEAVE-IPSEC-IN  
	 
	chain WEAVE-CANARY  
	 
 
table ip mangle  
	chain KUBE-KUBELET-CANARY  
	 
	chain PREROUTING  
		type filter hook prerouting priority mangle; policy accept;
	 
	chain INPUT  
		type filter hook input priority mangle; policy accept;
		counter packets 35716863 bytes 5906910315 jump WEAVE-IPSEC-IN
	 
	chain FORWARD  
		type filter hook forward priority mangle; policy accept;
	 
	chain OUTPUT  
		type route hook output priority mangle; policy accept;
		counter packets 35804064 bytes 5938944956 jump WEAVE-IPSEC-OUT
	 
	chain POSTROUTING  
		type filter hook postrouting priority mangle; policy accept;
	 
	chain KUBE-PROXY-CANARY  
	 
	chain WEAVE-IPSEC-IN  
	 
	chain WEAVE-IPSEC-IN-MARK  
		counter packets 0 bytes 0 meta mark set mark or 0x20000
	 
	chain WEAVE-IPSEC-OUT  
	 
	chain WEAVE-IPSEC-OUT-MARK  
		counter packets 0 bytes 0 meta mark set mark or 0x20000
	 
	chain WEAVE-CANARY  
	 
 
Wow. That s a lot of nftables entries, but it explains what s going on. We have a nat entry for:
meta l4proto tcp ip daddr 10.107.66.138 tcp dport 8080 counter packets 1 bytes 60 jump KUBE-SVC-666FUMINWJLRRQPD
which ends up going to KUBE-SEP-LYLDBZYLHY4MT3AQ and:
meta l4proto tcp counter packets 1 bytes 60 dnat to 192.168.0.4:8080
So packets headed for our echoserver are eventually ending up in a container that has a local IP address of 192.168.0.4. Which we can see in our routing table via the weave interface. Mystery explained. We can see the ingress for the externally visible HTTP service as well:
meta l4proto tcp ip daddr 192.168.33.147 tcp dport 80 counter packets 0 bytes 0 jump KUBE-XLB-CG5I4G2RS3ZVWGLK
which ends up redirected to:
meta l4proto tcp counter packets 0 bytes 0 dnat to 192.168.0.5:80
So from that we d expect the IP inside the echoserver pod to be 192.168.0.4 and the IP address instead our nginx ingress pod to be 192.168.0.5. Let s look:
root@udon:/# docker ps   grep echoserver
7cbb177bee18   k8s.gcr.io/echoserver                 "/usr/local/bin/run. "   3 days ago   Up 3 days             k8s_echoserver_hello-node-59bffcc9fd-8hkgb_default_c7111c9e-7131-40e0-876d-be89d5ca1812_0
root@udon:/# docker exec -it 7cbb177bee18 /bin/bash
root@hello-node-59bffcc9fd-8hkgb:/# awk '/32 host/   print f    f=$2 ' <<< "$(</proc/net/fib_trie)"   sort -u
127.0.0.1
192.168.0.4
It s a slightly awkward method of determining the local IPs addresses due to the stripped down nature of the container, but it clearly shows the expected 192.168.0.4 address. I ve touched here upon the ability to actually enter a container and have a poke around its running environment by using docker directly. Next step is to use that to investigate what containers have actually been spun up and what they re doing. I ll also revisit networking when I get to the point of building a multi-node cluster, to examine how the bridging between different hosts is done.

27 May 2021

Michael Prokop: What to expect from Debian/bullseye #newinbullseye

Bullseye Banner, Copyright 2020 Juliette Taka Debian v11 with codename bullseye is supposed to be released as new stable release soon-ish (let s hope for June, 2021! :)). Similar to what we had with #newinbuster and previous releases, now it s time for #newinbullseye! I was the driving force at several of my customers to be well prepared for bullseye before its freeze, and since then we re on good track there overall. In my opinion, Debian s release team did (and still does) a great job I m very happy about how unblock requests (not only mine but also ones I kept an eye on) were handled so far. As usual with major upgrades, there are some things to be aware of, and hereby I m starting my public notes on bullseye that might be worth also for other folks. My focus is primarily on server systems and looking at things from a sysadmin perspective. Further readings Of course start with taking a look at the official Debian release notes, make sure to especially go through What s new in Debian 11 + Issues to be aware of for bullseye. Chris published notes on upgrading to Debian bullseye, and also anarcat published upgrade notes for bullseye. Package versions As a starting point, let s look at some selected packages and their versions in buster vs. bullseye as of 2021-05-27 (mainly having amd64 in mind):
Package buster/v10 bullseye/v11
ansible 2.7.7 2.10.8
apache 2.4.38 2.4.46
apt 1.8.2.2 2.2.3
bash 5.0 5.1
ceph 12.2.11 14.2.20
docker 18.09.1 20.10.5
dovecot 2.3.4 2.3.13
dpkg 1.19.7 1.20.9
emacs 26.1 27.1
gcc 8.3.0 10.2.1
git 2.20.1 2.30.2
golang 1.11 1.15
libc 2.28 2.31
linux kernel 4.19 5.10
llvm 7.0 11.0
lxc 3.0.3 4.0.6
mariadb 10.3.27 10.5.10
nginx 1.14.2 1.18.0
nodejs 10.24.0 12.21.0
openjdk 11.0.9.1 11.0.11+9 + 17~19
openssh 7.9p1 8.4p1
openssl 1.1.1d 1.1.1k
perl 5.28.1 5.32.1
php 7.3 7.4+76
postfix 3.4.14 3.5.6
postgres 11 13
puppet 5.5.10 5.5.22
python2 2.7.16 2.7.18
python3 3.7.3 3.9.2
qemu/kvm 3.1 5.2
ruby 2.5.1 2.7+2
rust 1.41.1 1.48.0
samba 4.9.5 4.13.5
systemd 241 247.3
unattended-upgrades 1.11.2 2.8
util-linux 2.33.1 2.36.1
vagrant 2.2.3 2.2.14
vim 8.1.0875 8.2.2434
zsh 5.7.1 5.8
Linux Kernel The bullseye release will ship a Linux kernel based on v5.10 (v5.10.28 as of 2021-05-27, with v5.10.38 pending in unstable/sid), whereas buster shipped kernel 4.19. As usual there are plenty of changes in the kernel area and this might warrant a separate blog entry, but to highlight some issues: One surprising change might be that the scrollback buffer (Shift + PageUp) is gone from the Linux console. Make sure to always use screen/tmux or handle output through a pager of your choice if you need all of it and you re in the console. The kernel provides BTF support (via CONFIG_DEBUG_INFO_BTF, see #973870), which means it s no longer necessary to install LLVM, Clang, etc (requiring >100MB of disk space), see Gregg s excellent blog post regarding the underlying rational. Sadly the libbpf-tools packaging didn t make it into bullseye (#978727), but if you want to use your own self-made Debian packages, my notes might be useful. With kernel version 5.4, SUBDIRS support was removed from kbuild, so if an out-of-tree kernel module (like a *-dkms package) fails to compile on bullseye, make sure to use a recent version of it which uses M= or KBUILD_EXTMOD= instead. Unprivileged user namespaces are enabled by default (see #898446 + #987777), so programs can create more restricted sandboxes without the need to run as root or via a setuid-root helper. If you prefer to keep this feature restricted (or tools like web browsers, WebKitGTK, Flatpak, don t work), use sysctl -w kernel.unprivileged_userns_clone=0 . The /boot/System.map file(s) no longer provide the actual data, you need to switch to the dbg package if you rely on that information:
% cat /boot/System.map-5.10.0-6-amd64 
ffffffffffffffff B The real System.map is in the linux-image-<version>-dbg package
Be aware though, that the *-dbg package requires ~5GB of additional disk space. Systemd systemd v247 made it into bullseye (updated from v241). Same as for the kernel this might warrant a separate blog entry, but to mention some highlights: Systemd in bullseye activates its persistent journal functionality by default (storing its files in /var/log/journal/, see #717388). systemd-timesyncd is no longer part of the systemd binary package itself, but available as standalone package. This allows usage of ntp, chrony, openntpd, without having systemd-timesyncd installed (which prevents race conditions like #889290, which was biting me more than once). journalctl gained new options:
--cursor-file=FILE      Show entries after cursor in FILE and update FILE
--facility=FACILITY...  Show entries with the specified facilities
--image=IMAGE           Operate on files in filesystem image
--namespace=NAMESPACE   Show journal data from specified namespace
--relinquish-var        Stop logging to disk, log to temporary file system
--smart-relinquish-var  Similar, but NOP if log directory is on root mount
systemctl gained new options:
clean UNIT...                       Clean runtime, cache, state, logs or configuration of unit
freeze PATTERN...                   Freeze execution of unit processes
thaw PATTERN...                     Resume execution of a frozen unit
log-level [LEVEL]                   Get/set logging threshold for manager
log-target [TARGET]                 Get/set logging target for manager
service-watchdogs [BOOL]            Get/set service watchdog state
--with-dependencies                 Show unit dependencies with 'status', 'cat', 'list-units', and 'list-unit-files'
 -T --show-transaction              When enqueuing a unit job, show full transaction
 --what=RESOURCES                   Which types of resources to remove
--boot-loader-menu=TIME             Boot into boot loader menu on next boot
--boot-loader-entry=NAME            Boot into a specific boot loader entry on next boot
--timestamp=FORMAT                  Change format of printed timestamps
If you use systemctl edit to adjust overrides, then you ll now also get the existing configuration file listed as comment, which I consider very helpful. The MACAddressPolicy behavior with systemd naming schema v241 changed for virtual devices (I plan to write about this in a separate blog post). There are plenty of new manual pages: systemd also gained new unit configurations related to security hardening: Another new unit configuration is SystemCallLog= , which supports listing the system calls to be logged. This is very useful for for auditing or temporarily when constructing system call filters. The cgroupv2 change is also documented in the release notes, but to explicitly mention it also here, quoting from /usr/share/doc/systemd/NEWS.Debian.gz:
systemd now defaults to the unified cgroup hierarchy (i.e. cgroupv2).
This change reflects the fact that cgroups2 support has matured
substantially in both systemd and in the kernel.
All major container tools nowadays should support cgroupv2.
If you run into problems with cgroupv2, you can switch back to the previous,
hybrid setup by adding systemd.unified_cgroup_hierarchy=false to the
kernel command line.
You can read more about the benefits of cgroupv2 at
https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html
Note that cgroup-tools (lssubsys + lscgroup etc) don t work in cgroup2/unified hierarchy yet (see #959022 for the details). Configuration management puppet s upstream doesn t provide packages for bullseye yet (see PA-3624 + MODULES-11060), and sadly neither v6 nor v7 made it into bullseye, so when using the packages from Debian you re still stuck with v5.5 (also see #950182). ansible is also available, and while it looked like that only version 2.9.16 would make it into bullseye (see #984557 + #986213), actually version 2.10.8 made it into bullseye. chef was removed from Debian and is not available with bullseye (due to trademark issues). Prometheus stack Prometheus server was updated from v2.7.1 to v2.24.1, and the prometheus service by default applies some systemd hardening now. Also all the usual exporters are still there, but bullseye also gained some new ones: Virtualization docker (v20.10.5), ganeti (v3.0.1), libvirt (v7.0.0), lxc (v4.0.6), openstack, qemu/kvm (v5.2), xen (v4.14.1), are all still around, though what s new and noteworthy is that podman version 3.0.1 (tool for managing OCI containers and pods) made it into bullseye. If you re using the docker packages from upstream, be aware that they still don t seem to understand Debian package version handling. The docker* packages will not be automatically considered for upgrade, as 5:20.10.6~3-0~debian-buster is considered newer than 5:20.10.6~3-0~debian-bullseye:
% apt-cache policy docker-ce
  docker-ce:
    Installed: 5:20.10.6~3-0~debian-buster
    Candidate: 5:20.10.6~3-0~debian-buster
    Version table:
   *** 5:20.10.6~3-0~debian-buster 100
          100 /var/lib/dpkg/status
       5:20.10.6~3-0~debian-bullseye 500
          500 https://download.docker.com/linux/debian bullseye/stable amd64 Packages
Vagrant is available in version 2.2.14, the package from upstream works perfectly fine on bullseye as well. If you re relying on VirtualBox, be aware that upstream doesn t provide packages for bullseye yet, but the package from Debian/unstable (v6.1.22 as of 2021-05-27) works fine on bullseye (VirtualBox isn t shipped with stable releases since quite some time due to lack of cooperation from upstream on security support for older releases, see #794466). If you rely on the virtualbox-guest-additions-iso and its shared folders support, you might be glad to hear that v6.1.22 made it into bullseye (see #988783), properly supporting more recent kernel versions like present in bullseye. debuginfod There s a new service debuginfod.debian.net (see debian-devel-announce and Debian Wiki), which makes the debugging experience way smoother. You no longer need to download the debugging Debian packages (*-dbgsym/*-dbg), but instead can fetch them on demand, by exporting the following variables (before invoking gdb or alike):
% export DEBUGINFOD_PROGRESS=1    # for optional download progress reporting
% export DEBUGINFOD_URLS="https://debuginfod.debian.net"
BTW: if you can t rely on debuginfod (for whatever reason), I d like to point your attention towards find-dbgsym-packages from the debian-goodies package. Vim Sadly Vim 8.2 once again makes another change for bad defaults (hello mouse behavior!). When incsearch is set, it also applies to :substitute. This makes it veeeeeeeeeery annoying when running something like :%s/\s\+$// to get rid of trailing whitespace characters, because if there are no matches it jumps to the beginning of the file and then back, sigh. To get the old behavior back, you can use this:
au CmdLineEnter : let s:incs = &incsearch   set noincsearch
au CmdLineLeave : let &incsearch = s:incs
rsync rsync was updated from v3.1.3 to v3.2.3. It provides various checksum enhancements (see option --checksum-choice). We got new capabilities (hardlink-specials, atimes, optional protect-args, stop-at, no crtimes) and the addition of zstd and lz4 compression algorithms. And we got new options: OpenSSH OpenSSH was updated from v7.9p1 to 8.4p1, so if you re interested in all the changes, check out the release notes between those version (8.0, 8.1, 8.2, 8.3 + 8.4). Let s highlight some notable new features: Misc unsorted

25 May 2021

Vincent Bernat: Jerikan+Ansible: a configuration management system for network

There are many resources for network automation with Ansible. Most of them only expose the first steps or limit themselves to a narrow scope. They give no clue on how to expand from that. Real network environments may be large, versatile, heterogeneous, and filled with exceptions. The lack of real-world examples for Ansible deployments, unlike Puppet and SaltStack, leads many teams to build brittle and incomplete automation solutions. We have released under an open-source license our attempt to tackle this problem: Here is a quick demo to configure a new peering:
This work is the collective effort of C dric Hasco t, Jean-Christophe Legatte, Lo c Pailhas, S bastien Hurtel, Tchadel Icard, and Vincent Bernat. We are the network team of Blade, a French company operating Shadow, a cloud-computing product. In May 2021, our company was bought by Octave Klaba and the infrastructure is being transferred to OVHcloud, saving Shadow as a product, but making our team redundant. Our network was around 800 devices, spanning over 10 datacenters with more than 2.5 Tbps of available egress bandwidth. The released material is therefore a substantial example of managing a medium-scale network using Ansible. We have left out the handling of our legacy datacenters to make the final result more readable while keeping enough material to not turn it into a trivial example.

Jerikan The first component is Jerikan. As input, it takes a list of devices, configuration data, templates, and validation scripts. It generates a set of configuration files for each device. Ansible could cover this task, but it has the following limitations:
  • it is slow;
  • errors are difficult to debug;1 and
  • the hierarchy to look up a variable is rigid.
Jerikan inputs and outputs
Jerikan inputs and outputs
If you want to follow the examples, you only need to have Docker and Docker Compose installed. Clone the repository and you are ready!

Source of truth We use YAML files, versioned with Git, as the single source of truth instead of using a database, like NetBox, or a mix of a database and text files. This provides many advantages:
  • anyone can use their preferred text editor;
  • the team prepares changes in branches;
  • the team reviews changes using merge requests;
  • the merge requests expose the changes to the generated configuration files;
  • rollback to a previous state is easy; and
  • it is fast.
The first file is devices.yaml. It contains the device list. The second file is classifier.yaml. It defines a scope for each device. A scope is a set of keys and values. It is used in templates and to look up data associated with a device.
$ ./run-jerikan scope to1-p1.sk1.blade-group.net
continent: apac
environment: prod
groups:
- tor
- tor-bgp
- tor-bgp-compute
host: to1-p1.sk1
location: sk1
member: '1'
model: dell-s4048
os: cumulus
pod: '1'
shorthost: to1-p1
The device name is matched against a list of regular expressions and the scope is extended by the result of each match. For to1-p1.sk1.blade-group.net, the following subset of classifier.yaml defines its scope:
matchers:
  - '^(([^.]*)\..*)\.blade-group\.net':
      environment: prod
      host: '\1'
      shorthost: '\2'
  - '\.(sk1)\.':
      location: '\1'
      continent: apac
  - '^to([12])-[as]?p(\d+)\.':
      member: '\1'
      pod: '\2'
  - '^to[12]-p\d+\.':
      groups:
        - tor
        - tor-bgp
        - tor-bgp-compute
  - '^to[12]-(p ap)\d+\.sk1\.':
      os: cumulus
      model: dell-s4048
The third file is searchpaths.py. It describes which directories to search for a variable. A Python function provides a list of paths to look up in data/ for a given scope. Here is a simplified version:2
def searchpaths(scope):
    paths = [
        "host/ scope[location] / scope[shorthost] ",
        "location/ scope[location] ",
        "os/ scope[os] - scope[model] ",
        "os/ scope[os] ",
        'common'
    ]
    for idx in range(len(paths)):
        try:
            paths[idx] = paths[idx].format(scope=scope)
        except KeyError:
            paths[idx] = None
    return [path for path in paths if path]
With this definition, the data for to1-p1.sk1.blade-group.net is looked up in the following paths:
$ ./run-jerikan scope to1-p1.sk1.blade-group.net
[ ]
Search paths:
  host/sk1/to1-p1
  location/sk1
  os/cumulus-dell-s4048
  os/cumulus
  common
Variables are scoped using a namespace that should be specified when doing a lookup. We use the following ones:
  • system for accounts, DNS, syslog servers,
  • topology for ports, interfaces, IP addresses, subnets,
  • bgp for BGP configuration
  • build for templates and validation scripts
  • apps for application variables
When looking up for a variable in a given namespace, Jerikan looks for a YAML file named after the namespace in each directory in the search paths. For example, if we look up a variable for to1-p1.sk1.blade-group.net in the bgp namespace, the following YAML files are processed: host/sk1/to1-p1/bgp.yaml, location/sk1/bgp.yaml, os/cumulus-dell-s4048/bgp.yaml, os/cumulus/bgp.yaml, and common/bgp.yaml. The search stops at the first match. The schema.yaml file allows us to override this behavior by asking to merge dictionaries and arrays across all matching files. Here is an excerpt of this file for the topology namespace:
system:
  users:
    merge: hash
  sampling:
    merge: hash
  ansible-vars:
    merge: hash
  netbox:
    merge: hash
The last feature of the source of truth is the ability to use Jinja2 templates for keys and values by prefixing them with ~ :
# In data/os/junos/system.yaml
netbox:
  manufacturer: Juniper
  model: "~  model upper  "
# In data/groups/tor-bgp-compute/system.yaml
netbox:
  role: net_tor_gpu_switch
Looking up for netbox in the system namespace for to1-p2.ussfo03.blade-group.net yields the following result:
$ ./run-jerikan scope to1-p2.ussfo03.blade-group.net
continent: us
environment: prod
groups:
- tor
- tor-bgp
- tor-bgp-compute
host: to1-p2.ussfo03
location: ussfo03
member: '1'
model: qfx5110-48s
os: junos
pod: '2'
shorthost: to1-p2
[ ]
Search paths:
[ ]
  groups/tor-bgp-compute
[ ]
  os/junos
  common
$ ./run-jerikan lookup to1-p2.ussfo03.blade-group.net system netbox
manufacturer: Juniper
model: QFX5110-48S
role: net_tor_gpu_switch
This also works for structured data:
# In groups/adm-gateway/topology.yaml
interface-rescue:
  address: "~  lookup('topology', 'addresses').rescue  "
  up:
    - "~ip route add default via   lookup('topology', 'addresses').rescue ipaddr('first_usable')   table rescue"
    - "~ip rule add from   lookup('topology', 'addresses').rescue ipaddr('address')   table rescue priority 10"
# In groups/adm-gateway-sk1/topology.yaml
interfaces:
  ens1f0: "~  lookup('topology', 'interface-rescue')  "
This yields the following result:
$ ./run-jerikan lookup gateway1.sk1.blade-group.net topology interfaces
[ ]
ens1f0:
  address: 121.78.242.10/29
  up:
  - ip route add default via 121.78.242.9 table rescue
  - ip rule add from 121.78.242.10 table rescue priority 10
When putting data in the source of truth, we use the following rules:
  1. Don t repeat yourself.
  2. Put the data in the most specific place without breaking the first rule.
  3. Use templates with parsimony, mostly to help with the previous rules.
  4. Restrict the data model to what is needed for your use case.
The first rule is important. For example, when specifying IP addresses for a point-to-point link, only specify one side and deduce the other value in the templates. The last rule means you do not need to mimic a BGP YANG model to specify BGP peers and policies:
peers:
  transit:
    cogent:
      asn: 174
      remote:
        - 38.140.30.233
        - 2001:550:2:B::1F9:1
      specific-import:
        - name: ATT-US
          as-path: ".*7018$"
          lp-delta: 50
  ix-sfmix:
    rs-sfmix:
      monitored: true
      asn: 63055
      remote:
        - 206.197.187.253
        - 206.197.187.254
        - 2001:504:30::ba06:3055:1
        - 2001:504:30::ba06:3055:2
    blizzard:
      asn: 57976
      remote:
        - 206.197.187.42
        - 2001:504:30::ba05:7976:1
      irr: AS-BLIZZARD

Templates The list of templates to compile for each device is stored in the source of truth, under the build namespace:
$ ./run-jerikan lookup edge1.ussfo03.blade-group.net build templates
data.yaml: data.j2
config.txt: junos/main.j2
config-base.txt: junos/base.j2
config-irr.txt: junos/irr.j2
$ ./run-jerikan lookup to1-p1.ussfo03.blade-group.net build templates
data.yaml: data.j2
config.txt: cumulus/main.j2
frr.conf: cumulus/frr.j2
interfaces.conf: cumulus/interfaces.j2
ports.conf: cumulus/ports.j2
dhcpd.conf: cumulus/dhcp.j2
default-isc-dhcp: cumulus/default-isc-dhcp.j2
authorized_keys: cumulus/authorized-keys.j2
motd: linux/motd.j2
acl.rules: cumulus/acl.j2
rsyslog.conf: cumulus/rsyslog.conf.j2
Templates are using Jinja2. This is the same engine used in Ansible. Jerikan ships some custom filters but also reuse some of the useful filters from Ansible, notably ipaddr. Here is an excerpt of templates/junos/base.j2 to configure DNS and NTP servers on Juniper devices:
system  
  ntp  
 % for ntp in lookup("system", "ntp") % 
    server   ntp  ;
 % endfor % 
   
  name-server  
 % for dns in lookup("system", "dns") % 
      dns  ;
 % endfor % 
   
 
The equivalent template for Cisco IOS-XR is:
 % for dns in lookup('system', 'dns') % 
domain vrf VRF-MANAGEMENT name-server   dns  
 % endfor % 
!
 % for syslog in lookup('system', 'syslog') % 
logging   syslog   vrf VRF-MANAGEMENT
 % endfor % 
!
There are three helper functions provided:
  • devices() returns the list of devices matching a set of conditions on the scope. For example, devices("location==ussfo03", "groups==tor-bgp") returns the list of devices in San Francisco in the tor-bgp group. You can also omit the operator if you want the specified value to be equal to the one in the local scope. For example, devices("location") returns devices in the current location.
  • lookup() does a key lookup. It takes the namespace, the key, and optionally, a device name. If not provided, the current device is assumed.
  • scope() returns the scope of the provided device.
Here is how you would define iBGP sessions between edge devices in the same location:
 % for neighbor in devices("location", "groups==edge") if neighbor != device % 
   % for address in lookup("topology", "addresses", neighbor).loopback tolist % 
protocols bgp group IPV  address ipv  -EDGES-IBGP  
  neighbor   address    
    description "IPv  address ipv  : iBGP to   neighbor  ";
   
 
   % endfor % 
 % endfor % 
We also have a global key-value store to save information to be reused in another template or device. This is quite useful to automatically build DNS records. First, capture the IP address inserted into a template with store() as a filter:
interface Loopback0
 description 'Loopback:'
  % for address in lookup('topology', 'addresses').loopback tolist % 
 ipv  address ipv   address   address store('addresses', 'Loopback0') ipaddr('cidr')  
  % endfor % 
!
Then, reuse it later to build DNS records by iterating over store():4
 % for device, ip, interface in store('addresses') % 
   % set interface = interface replace('/', '-') replace('.', '-') replace(':', '-') % 
   % set name = ' . '.format(interface lower, device) % 
  name  . IN   'A' if ip ipv4 else 'AAAA'     ip ipaddr('address')  
 % endfor % 
Templates are compiled locally with ./run-jerikan build. The --limit argument restricts the devices to generate configuration files for. Build is not done in parallel because a template may depend on the data collected by another template. Currently, it takes 1 minute to compile around 3000 files spanning over 800 devices.
Jerikan outputs when building templates
Output of Jerikan after building configuration files for six devices
When an error occurs, a detailed traceback is displayed, including the template name, the line number and the value of all visible variables. This is a major time-saver compared to Ansible!
templates/opengear/config.j2:15: in top-level template code
    config.interfaces.  interface  .netmask   adddress   ipaddr("netmask")  
        continent  = 'us'
        device     = 'con1-ag2.ussfo03.blade-group.net'
        environment = 'prod'
        host       = 'con1-ag2.ussfo03'
        infos      =  'address': '172.30.24.19/21' 
        interface  = 'wan'
        location   = 'ussfo03'
        loop       = <LoopContext 1/2>
        member     = '2'
        model      = 'cm7132-2-dac'
        os         = 'opengear'
        shorthost  = 'con1-ag2'
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
value = JerkianUndefined, query = 'netmask', version = False, alias = 'ipaddr'
[ ]
        # Check if value is a list and parse each element
        if isinstance(value, (list, tuple, types.GeneratorType)):
            _ret = [ipaddr(element, str(query), version) for element in value]
            return [item for item in _ret if item]
>       elif not value or value is True:
E       jinja2.exceptions.UndefinedError: 'dict object' has no attribute 'adddress'
We don t have general-purpose rules when writing templates. Like for the source of truth, there is no need to create generic templates able to produce any BGP configuration. There is a balance to be found between readability and avoiding duplication. Templates can become scary and complex: sometimes, it s better to write a filter or a function in jerikan/jinja.py. Mastering Jinja2 is a good investment. Take time to browse through our templates as some of them show interesting features.

Checks Optionally, each configuration file can be validated by a script in the checks/ directory. Jerikan looks up the key checks in the build namespace to know which checks to run:
$ ./run-jerikan lookup edge1.ussfo03.blade-group.net build checks
- description: Juniper configuration file syntax check
  script: checks/junoser
  cache:
    input: config.txt
    output: config-set.txt
- description: check YAML data
  script: checks/data.yaml
  cache: data.yaml
In the above example, checks/junoser is executed if there is a change to the generated config.txt file. It also outputs a transformed version of the configuration file which is easier to understand when using diff. Junoser checks a Junos configuration file using Juniper s XML schema definition for Netconf.5 On error, Jerikan displays:
jerikan/build.py:127: RuntimeError
-------------- Captured syntax check with Junoser call --------------
P: checks/junoser edge2.ussfo03.blade-group.net
C: /app/jerikan
O:
E: Invalid syntax:  set system syslog archive size 10m files 10 word-readable
S: 1

Integration into GitLab CI The next step is to compile the templates using a CI. As we are using GitLab, Jerikan ships with a .gitlab-ci.yml file. When we need to make a change, we create a dedicated branch and a merge request. GitLab compiles the templates using the same environment we use on our laptops and store them as an artifact.
Merge requests in GitLab for a change
Merge request to add a new port in USSFO03. The templates were compiled successfully but approval from another team member is still required to merge.
Before approving the merge request, another team member looks at the changes in data and templates but also the differences for the generated configuration files:
Differences for generated configuration files
The change configures a port on the Juniper device, adds records to DNS, and updates NetBox with the new IP addresses (not shown).

Ansible After Jerikan has built the configuration files, Ansible takes over. It is also packaged as a Docker image to avoid the trouble to maintain the right Python virtual environment and ensure everyone is using the same versions.

Inventory Jerikan has generated an inventory file. It contains all the managed devices, the variables defined for each of them and the groups converted to Ansible groups:
ob1-n1.sk1.blade-group.net ansible_host=172.29.15.12 ansible_user=blade ansible_connection=network_cli ansible_network_os=ios
ob2-n1.sk1.blade-group.net ansible_host=172.29.15.13 ansible_user=blade ansible_connection=network_cli ansible_network_os=ios
ob1-n1.ussfo03.blade-group.net ansible_host=172.29.15.12 ansible_user=blade ansible_connection=network_cli ansible_network_os=ios
none ansible_connection=local
[oob]
ob1-n1.sk1.blade-group.net
ob2-n1.sk1.blade-group.net
ob1-n1.ussfo03.blade-group.net
[os-ios]
ob1-n1.sk1.blade-group.net
ob2-n1.sk1.blade-group.net
ob1-n1.ussfo03.blade-group.net
[model-c2960s]
ob1-n1.sk1.blade-group.net
ob2-n1.sk1.blade-group.net
ob1-n1.ussfo03.blade-group.net
[location-sk1]
ob1-n1.sk1.blade-group.net
ob2-n1.sk1.blade-group.net
[location-ussfo03]
ob1-n1.ussfo03.blade-group.net
[in-sync]
ob1-n1.sk1.blade-group.net
ob2-n1.sk1.blade-group.net
ob1-n1.ussfo03.blade-group.net
none
in-sync is a special group for devices which configuration should match the golden configuration. Daily and unattended, Ansible should be able to push configurations to this group. The mid-term goal is to cover all devices. none is a special device for tasks not related to a specific host. This includes synchronizing NetBox, IRR objects, and the DNS, updating the RPKI, and building the geofeed files.

Playbook We use a single playbook for all devices. It is described in the ansible/playbooks/site.yaml file. Here is a shortened version:
- hosts: adm-gateway:!done
  strategy: mitogen_linear
  roles:
    - blade.linux
    - blade.adm-gateway
    - done
- hosts: os-linux:!done
  strategy: mitogen_linear
  roles:
    - blade.linux
    - done
- hosts: os-junos:!done
  gather_facts: false
  roles:
    - blade.junos
    - done
- hosts: os-opengear:!done
  gather_facts: false
  roles:
    - blade.opengear
    - done
- hosts: none:!done
  gather_facts: false
  roles:
    - blade.none
    - done
A host executes only one of the play. For example, a Junos device executes the blade.junos role. Once a play has been executed, the device is added to the done group and the other plays are skipped. The playbook can be executed with the configuration files generated by the GitLab CI using the ./run-ansible-gitlab command. This is a wrapper around Docker and the ansible-playbook command and it accepts the same arguments. To deploy the configuration on the edge devices for the SK1 datacenter in check mode, we use:
$ ./run-ansible-gitlab playbooks/site.yaml --limit='edge:&location-sk1' --diff --check
[ ]
PLAY RECAP *************************************************************
edge1.sk1.blade-group.net  : ok=6    changed=0    unreachable=0    failed=0    skipped=3    rescued=0    ignored=0
edge2.sk1.blade-group.net  : ok=5    changed=0    unreachable=0    failed=0    skipped=1    rescued=0    ignored=0
We have some rules when writing roles:
  • --check must detect if a change is needed;
  • --diff must provide a visualization of the planned changes;
  • --check and --diff must not display anything if there is nothing to change;
  • writing a custom module tailored to our needs is a valid solution;
  • the whole device configuration is managed;6
  • secrets must be stored in Vault;
  • templates should be avoided as we have Jerikan for that; and
  • avoid duplication and reuse tasks.7
We avoid using collections from Ansible Galaxy, the exception being collections to connect and interact with vendor devices, like cisco.iosxr collection. The quality of Ansible Galaxy collections is quite random and it is an additional maintenance burden. It seems better to write roles tailored to our needs. The collections we use are in ci/ansible/ansible-galaxy.yaml. We use Mitogen to get a 10 speedup on Ansible executions on Linux hosts. We also have a few playbooks for operational purpose: upgrading the OS version, isolate an edge router, etc. We were also planning on how to add operational checks in roles: are all the BGP sessions up? They could have been used to validate a deployment and rollback if there is an issue. Currently, our playbooks are run from our laptops. To keep tabs, we are using ARA. A weekly dry-run on devices in the in-sync group also provides a dashboard on which devices we need to run Ansible on.

Configuration data and templates Jerikan ships with pre-populated data and templates matching the configuration of our USSFO03 and SK1 datacenters. They do not exist anymore but, we promise, all this was used in production back in the days!
Network architecture for Blade datacenter
The latest iteration of our network infrastructure for SK1, USSFO03, and future data centers. The production network is using BGPttH using a spine-leaf fabric. The out-of-band network is using a simple L2 design, using the spanning tree protocol, as well as a set of console servers.
Notably, you can find the configuration for:
our edge routers
Some are running on Junos, like edge2.ussfo03, the others on IOS-XR, like edge1.sk1. The implemented functionalities are similar in both cases and we could swap one for the other. It includes the BGP configuration for transits, peerings, and IX as well as the associated BGP policies. PeeringDB is queried to get the maximum number of prefixes to accept for peerings. bgpq3 and a containerized IRRd help to filter received routes. A firewall is added to protect the routing engine. Both IPv4 and IPv6 are configured.
our BGP-based fabric
BGP is used inside the datacenter8 and is extended on bare-metal hosts. The configuration is automatically derived from the device location and the port number.9 Top-of-the-rack devices are using passive BGP sessions for ports towards servers. They are also serving a provisioning network to let them boot using DHCP and PXE. They also act as a DHCP server. The design is multivendor. Some devices are running Cumulus Linux, like to1-p1.ussfo03, while some others are running Junos, like to1-p2.ussfo03.
our out-of-band fabric
We are using Cisco Catalyst 2960 switches to build an L2 out-of-band network. To provide redundancy and saving a few bucks on wiring, we build small loops and run the spanning-tree protocol. See ob1-p1.ussfo03. It is redundantly connected to our gateway servers. We also use OpenGear devices for console access. See con1-n1.ussfo03
our administrative gateways
These Linux servers have multiple purposes: SSH jump boxes, rescue connection, direct access to the out-of-band network, zero-touch provisioning of network devices,10 Internet access for management flows, centralization of the console servers using Conserver, and API for autoconfiguration of BGP sessions for bare-metal servers. They are the first servers installed in a new datacenter and are used to provision everything else. Check both the generated files and the associated Ansible tasks.

  1. Ansible does not even provide a line number when there is an error in a template. You may need to find the problem by bisecting.
    $ ansible --version
    ansible 2.10.8
    [ ]
    $ cat test.j2
    Hello   name  !
    $ ansible all -i localhost, \
    >  --connection=local \
    >  -m template \
    >  -a "src=test.j2 dest=test.txt"
    localhost   FAILED! =>  
        "changed": false,
        "msg": "AnsibleUndefinedVariable: 'name' is undefined"
     
    
  2. You may recognize the same concepts as in Hiera, the hierarchical key-value store from Puppet. At first, we were using Jerakia, a similar independent store exposing an HTTP REST interface. However, the lookup overhead is too large for our use. Jerikan implements the same functionality within a Python function.
  3. The list of available filters is mangled inside jerikan/jinja.py. This is a remain of the fact we do not maintain Jerikan as a standalone software.
  4. This is a bit confusing: we have a store() filter and a store() function. With Jinja2, filters and functions live in two different namespaces.
  5. We are using a fork with some modifications to be able to validate our configurations and exposing an HTTP service to reduce the time spent on each configuration check.
  6. There is a trend in network automation to automate a configuration subset, for example by having a playbook to create a new BGP session. We believe this is wrong: with time, your configuration will get out-of-sync with its expected state, notably hand-made changes will be left undetected.
  7. See ansible/roles/blade.linux/tasks/firewall.yaml and ansible/roles/blade.linux/tasks/interfaces.yaml. They are meant to be called when needed, using import_role.
  8. We also have some datacenters using BGP EVPN VXLAN at medium-scale using Juniper devices. As they are still in production today, we didn t include this feature but we may publish it in the future.
  9. In retrospect, this may not be a good idea unless you are pretty sure everything is uniform (number of switches for each layer, number of ports). This was not our case. We now think it is a better idea to assign a prefix to each device and write it in the source of truth.
  10. Non-linux based devices are upgraded and configured unattended. Cumulus Linux devices are automatically upgraded on install but the final configuration has to be pushed using Ansible: we didn t want to duplicate the configuration process using another tool.

22 May 2021

Ritesh Raj Sarraf: Setting Up a Secure Webapp

As a person who prefers full access to data in the simplest format, while at the same time having it useful with latest technologies, my quest for trying things out is an ongoing activity. Earlier, I blogged about my needs of collating news feeds in a simple format, readily accessible offline, while still being useful and aligned with the modern paradigm. In today s age, the other common aspect of our life, is digitization of moments. With the advent of great technology and affordable economics, the world now has access to great devices to capture moments in digital form. Most people, these days, are equipped with smart devices, like mobile phones, that come with pretty good image capturing devices. Our lives, our societies, how we interact; a lot of it is now built around the assumption of smart devices and digital services. A lot of good things have happened of it. We are now able to send messages to people, securely, in a matter of seconds. We are now able to capture moments, which otherwise we d often miss; all thanks to devices like smart mobile phones that most of all carry almost all along with us. In this regard, we are quite indebted to the technology revolution that has improved life styles all over. Of course, like every coin has a flip side, thus too, too much of obsession with digital life, also has its drawbacks. A simple reminder to self should always be about what a human life is designed for and try to live by its rules.

Moments Given the tools general availability, we are all more used to capturing moments. Once upon a time, taking a photo meant going to a photo studio. Then came a generation where we d have personal devices with roll films, to which we captured the moments. And then get it processed from a photo developing service provider. And that is when we d know which all moments came out correct and which ones were spoilt. In such cases, there s always the wish I could have that moment again. Thankfully, now, in our current generation, we have the liberty to take pictures and validate them almost immediately. We also have the flexibility to take multiple shots of the moment and do the filtering later. There s also many intelligent and invasive services, all mostly provided free, to help you organize these moments; at a small cost of keeping an eye on your life activity. In a summary, mankind, now, generates lots and lots of data. So much lot that now even mammoths like Google are forced to make a call whether it is more profitable to sniff user activity while providing them a service for free, or ask people to pay otherwise too.

Privacy Many of us are wary of the amount of personal data we generate, which is our asset; and how the big tech giants want a piece of it in the name of free services. And in such quest, free aside, there s always a lookout for privacy savvy tools that can help us draw a bold line in between Public and Private

Google Photos Google Photos has been a great tool. The way it organizes, siphons and present your data is simply amazing. No good would have been the photos taken, if they weren t easily searchable, organized, annotated, and presented. But Google Photos is proprietary and invasive. The amount of information they have access to should be a concern to all people. For services that invade so much, the world needs Free Services.

PhotoPrism I only came across this project around a month ago, while the project has been around since 2019. So far, in my exploration, this is one of the best Free Software tools to manage and organize my digital photos. The other favorite tool that I regularly depend on is Digikam and it still is a gem. In a gist, PhotoPrism aims to be the equivalent of Google Photos, for the privacy savvy people. As of date, it has a decent list of features available. And for some of the missing ones, I ve come up with a fairly okay workflow with other tools, which is one of the reasons of this blog post. PhotoPrism is a web app, written in the Go Programming Language. Its layout and workflow as a Photo Management application is similar to Google Photos. It is very performant compared to other applications. Since it is a Progressive Web App, access through a Laptop, Tablet or Mobile is almost the same. It uses Google TensorFlow for some of its features and thus you feel like using Google Photos in some regard. Some shortcomings and workarounds
  • Facial Recognition: To date, facial recognition is a planned feature. But this was easy to tackle given that Digikam has pretty solid facial recognition. So I use Digikam to detect, recognize and annotate faces. And then PhotoPrism is happy enough to use those annotations and present relevant data.
  • HTTP Web App: The upstream project has done a good job of making use of Docker container technology in presenting this web app solution. A software solution, the equivalent of a Google Photos, does need a heavyweight config. In free software, it is all about reusing available tools. PhotoPrism makes use of tools like MySQL, Vue.js, TensorFlow, GoLang, GoLibs and strives to provide a single package solution, all thanks to Docker containers.
In its current offering, PhotoPrism is run as a HTTP Web App. I wanted to have an added layer of security on top of it. And thus run an nginx reverse proxy on top of it. Along with it, I run the proxy service on HTTPS, thus making all traffic from clients to the proxy encrypted. I also wanted an added layer of HTTP AUTH on top, so I explored some options and finally settled down with http-auth-digest Also, in the current implementation, PhotoPrism doesn t have a strong notion of normal and private photos in its data organization. I wanted normal photos available under a standard auth realm and private photos under a different realm. And along with a different realm, I also wanted some added security directives for it. So far, it looks like I ve put together a decent solution with the help of nginx.
  • First of all, since the port from the host is forwarded to the docker instance, that needed to be controlled. Instead of the default of listening on all interfaces, I changed it to loopback only. Because my primary and only interface is going to be the nginx reverse proxy
  • Setup nginx with a self-signed certificate to have all communication encrypted.
  • Setup nginx as a reverse proxy to talk to PhotoPrism.
    server  
       listen 80;
       listen [::]:80;
       server_name lenovo;
       return 302 https://$host$request_uri;
       rewrite ^ https://$http_host$request_uri? permanent;    # force redirect http to https
        server_tokens off;
     
    server  
    listen 443 ssl http2 default_server;
    listen [::]:443 ssl http2 default_server;
    ssl_certificate_key /etc/ssl/private/ssl-cert-snakeoil.key;
    ssl_certificate /etc/ssl/certs/ssl-cert-snakeoil.pem;
    server_tokens off;
    server_name lenovo;
    client_max_body_size 500M;
        auth_digest_expires 900s;
        auth_digest_evasion_time 5s;
        auth_digest_replays 500;
    location /private  
        auth_digest 'abc';
        auth_digest_user_file /etc/nginx/htdigest;
        auth_digest_expires 900s;
        auth_digest_evasion_time 5s;
        auth_digest_replays 500;
        proxy_pass http://localhost:2342/private;
     
    location /discover  
        auth_digest 'abc';
        auth_digest_user_file /etc/nginx/htdigest;
        auth_digest_expires 900s;
        auth_digest_evasion_time 5s;
        auth_digest_replays 500;
        proxy_pass http://localhost:2342/discover;
     
    location /  
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $host;
        proxy_buffering off;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_pass http://localhost:2342;
          
        auth_basic "Priv";
        auth_basic_user_file /etc/nginx/htpasswd;
     
     
    
  • nginx packaging: I was so happy to see the simplicity of the nginx packaging in Debian. Becuase http-auth-digest is not upstream, it needs to be pulled in separately and compiled. I was happy to see how simple the packaging structure of nginx in Debian is. It was just a matter of putting in the module in the right modules location, which as structured such in the packaging falls under the debian/ packaging sub-folder, that any future upgrades will be quite easy to manage.
  • http-auth-digest: I d love to see http-auth-digest module be part of the upstream package. While I m a web n00b, I felt this module perfect for my use case. From what I ve understood, set up and tested so far, this module fills in all my requirements; which is more of like a session management.
With the combined setup in place, https://host is authenticated with a different set of credentials. On the other hand, https://host/discover and /private get covered with a different set of credentials and policies. While, this will continue to be an ongoing effort and audit of the services that I build, so far now, I feel this is in decent shape that I can use it as my daily driver. The end result is:
nginx auth prompt
nginx auth prompt
PhotoPrism Photo List
PhotoPrism Photo List
PhotoPrism Menu
PhotoPrism Menu

Updates
  • Things can really get frustrating at times. These days, it is Google that contributes to it. https://bugs.chromium.org/p/chromium/issues/detail?id=544244
    • It is is now fair to say that Google is big enough to rewrite all the standards. Or at least break them. Or best, their arrogance of it. This bug report is a fine example of what other ways it could have been dealt.

28 April 2021

Russell Coker: Links April 2021

Dr Justin Lehmiller s blog post comparing his official (academic style) and real biographies is interesting [1]. Also the rest of his blog is interesting too, he works at the Kinsey Institute so you know he s good. Media Matters has an interesting article on the spread of vaccine misinformation on Instagram [2]. John Goerzen wrote a long post summarising some of the many ways of having a decentralised Internet [3]. One problem he didn t address is how to choose between them, I could spend months of work to setup a fraction of those services. Erasmo Acosta wrote an interesting medium article Could Something as Pedestrian as the Mitochondria Unlock the Mystery of the Great Silence? [4]. I don t know enough about biology to determine how plausible this is. But it is a worry, I hope that humans will meet extra-terrestrial intelligences at some future time. Meredith Haggerty wrote an insightful Medium article about the love vs money aspects of romantic comedies [5]. Changes in viewer demographics would be one factor that makes lead actors in romantic movies significantly less wealthy in recent times. Informative article about ZIP compression and the history of compression in general [6]. Vice has an insightful article about one way of taking over SMS access of phones without affecting voice call or data access [7]. With this method the victom won t notice that they are having their sservice interfered with until it s way too late. They also explain the chain of problems in the US telecommunications industry that led to this. I wonder what s happening in this regard in other parts of the world. The clown code of ethics (8 Commandments) is interesting [8]. Sam Hartman wrote an insightful blog post about the problems with RMS and how to deal with him [9]. Also Sam Whitton has an interesting take on this [10]. Another insightful post is by Selam G about RMS long history of bad behavior and the way universities are run [11]. Cory Doctorow wrote an insightful article for Locus about free markets with a focus on DRM on audio books [12]. We need legislative changes to fix this!

25 April 2021

Antoine Beaupr : Lost article ideas

I wrote for LWN for about two years. During that time, I wrote (what seems to me an impressive) 34 articles, but I always had a pile of ideas in the back of my mind. Those are ideas, notes, and scribbles lying around. Some were just completely abandoned because they didn't seem a good fit for LWN. Concretely, I stored those in branches in a git repository, and used the branch name (and, naively, the last commit log) as indicators of the topic. This was the state of affairs when I left:
remotes/private/attic/novena                    822ca2bb add letter i sent to novena, never published
remotes/private/attic/secureboot                de09d82b quick review, add note and graph
remotes/private/attic/wireguard                 5c5340d1 wireguard review, tutorial and comparison with alternatives
remotes/private/backlog/dat                     914c5edf Merge branch 'master' into backlog/dat
remotes/private/backlog/packet                  9b2c6d1a ham radio packet innovations and primer
remotes/private/backlog/performance-tweaks      dcf02676 config notes for http2
remotes/private/backlog/serverless              9fce6484 postponed until kubecon europe
remotes/private/fin/cost-of-hosting             00d8e499 cost-of-hosting article online
remotes/private/fin/kubecon                     f4fd7df2 remove published or spun off articles
remotes/private/fin/kubecon-overview            21fae984 publish kubecon overview article
remotes/private/fin/kubecon2018                 1edc5ec8 add series
remotes/private/fin/netconf                     3f4b7ece publish the netconf articles
remotes/private/fin/netdev                      6ee66559 publish articles from netdev 2.2
remotes/private/fin/pgp-offline                 f841deed pgp offline branch ready for publication
remotes/private/fin/primes                      c7e5b912 publish the ROCA paper
remotes/private/fin/runtimes                    4bee1d70 prepare publication of runtimes articles
remotes/private/fin/token-benchmarks            5a363992 regenerate timestamp automatically
remotes/private/ideas/astropy                   95d53152 astropy or python in astronomy
remotes/private/ideas/avaneya                   20a6d149 crowdfunded blade-runner-themed GPLv3 simcity-like simulator
remotes/private/ideas/backups-benchmarks        fe2f1f13 review of backup software through performance and features
remotes/private/ideas/cumin                     7bed3945 review of the cumin automation tool from WM foundation
remotes/private/ideas/future-of-distros         d086ca0d modern packaging problems and complex apps
remotes/private/ideas/on-dying                  a92ad23f another dying thing
remotes/private/ideas/openpgp-discovery         8f2782f0 openpgp discovery mechanisms (WKD, etc), thanks to jonas meurer
remotes/private/ideas/password-bench            451602c0 bruteforce estimates for various password patterns compared with RSA key sizes
remotes/private/ideas/prometheus-openmetrics    2568dbd6 openmetrics standardizing prom metrics enpoints
remotes/private/ideas/telling-time              f3c24a53 another way of telling time
remotes/private/ideas/wallabako                 4f44c5da talk about wallabako, read-it-later + kobo hacking
remotes/private/stalled/bench-bench-bench       8cef0504 benchmarking http benchmarking tools
remotes/private/stalled/debian-survey-democracy 909bdc98 free software surveys and debian democracy, volunteer vs paid work
Wow, what a mess! Let's see if I can make sense of this:

Attic Those are articles that I thought about, then finally rejected, either because it didn't seem worth it, or my editors rejected it, or I just moved on:
  • novena: the project is ooold now, didn't seem to fit a LWN article. it was basically "how can i build my novena now" and "you guys rock!" it seems like the MNT Reform is the brain child of the Novena now, and I dare say it's even cooler!
  • secureboot: my LWN editors were critical of my approach, and probably rightly so - it's a really complex subject and I was probably out of my depth... it's also out of date now, we did manage secureboot in Debian
  • wireguard: LWN ended up writing extensive coverage, and I was biased against Donenfeld because of conflicts in a previous project

Backlog Those were articles I was planning to write about next.
  • dat: I already had written Sharing and archiving data sets with Dat, but it seems I had more to say... mostly performance issues, beaker, no streaming, limited adoption... to be investigated, I guess?
  • packet: a primer on data communications over ham radio, and the cool new tech that has emerged in the free software world. those are mainly notes about Pat, Direwolf, APRS and so on... just never got around to making sense of it or really using the tech...
  • performance-tweaks: "optimizing websites at the age of http2", the unwritten story of the optimization of this website with HTTP/2 and friends
  • serverless: god. one of the leftover topics at Kubecon, my notes on this were thin, and the actual subject, possibly even thinner... the only lie worse than the cloud is that there's no server at all! concretely, that's a pile of notes about Kubecon which I wanted to sort through. Probably belongs in the attic now.

Fin Those are finished articles, they were published on my website and LWN, but the branches were kept because previous drafts had private notes that should not be published.

Ideas A lot of those branches were actually just an empty commit, with the commitlog being the "pitch", more or less. I'd send that list to my editors, sometimes with a few more links (basically the above), and they would nudge me one way or the other. Sometimes they would actively discourage me to write about something, and I would do it anyways, send them a draft, and they would patiently make me rewrite it until it was a decent article. This was especially hard with the terminal emulator series, which took forever to write and even got my editors upset when they realized I had never installed Fedora (I ended up installing it, and I was proven wrong!)

Stalled Oh, and then there's those: those are either "ideas" or "backlog" that got so far behind that I just moved them out of the way because I was tired of seeing them in my list.
  • stalled/bench-bench-bench benchmarking http benchmarking tools, a horrible mess of links, copy-paste from terminals, and ideas about benchmarking... some of this trickled out into this benchmarking guide at Tor, but not much more than the list of tools
  • stalled/debian-survey-democracy: "free software surveys and Debian democracy, volunteer vs paid work"... A long standing concern of mine is that all Debian work is supposed to be volunteer, and paying explicitly for work inside Debian has traditionally been frowned upon, even leading to serious drama and dissent (remember Dunc-Tank)? back when I was writing for LWN, I was also doing paid work for Debian LTS. I also learned that a lot (most?) Debian Developers were actually being paid by their job to work on Debian. So I was confused by this apparent contradiction, especially given how the LTS project has been mostly accepted, while Dunc-Tank was not... See also this talk at Debconf 16. I had hopes that this study would show the "hunch" people have offered (that most DDs are paid to work on Debian) but it seems to show the reverse (only 36% of DDs, and 18% of all respondents paid). So I am still confused and worried about the sustainability of Debian.

What do you think? So that's all I got. As people might have noticed here, I have much less time to write these days, but if there's any subject in there I should pick, what is the one that you would find most interesting? Oh! and I should mention that you can write to LWN! If you think people should know more about some Linux thing, you can get paid to write for it! Pitch it to the editors, they won't bite. The worst that can happen is that they say "yes" and there goes two years of your life learning to write. Because no, you don't know how to write, no one does. You need an editor to write. That's why this article looks like crap and has a smiley. :)

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