Search Results: "rul"

16 November 2022

Antoine Beaupr : Wayland: i3 to Sway migration

I started migrating my graphical workstations to Wayland, specifically migrating from i3 to Sway. This is mostly to address serious graphics bugs in the latest Framwork laptop, but also something I felt was inevitable. The current status is that I've been able to convert my i3 configuration to Sway, and adapt my systemd startup sequence to the new environment. Screen sharing only works with Pipewire, so I also did that migration, which basically requires an upgrade to Debian bookworm to get a nice enough Pipewire release. I'm testing Wayland on my laptop, but I'm not using it as a daily driver because I first need to upgrade to Debian bookworm on my main workstation. Most irritants have been solved one way or the other. My main problem with Wayland right now is that I spent a frigging week doing the conversion: it's exciting and new, but it basically sucked the life out of all my other projects and it's distracting, and I want it to stop. The rest of this page documents why I made the switch, how it happened, and what's left to do. Hopefully it will keep you from spending as much time as I did in fixing this. TL;DR: Wayland is mostly ready. Main blockers you might find are that you need to do manual configurations, DisplayLink (multiple monitors on a single cable) doesn't work in Sway, HDR and color management are still in development. I had to install the following packages:
apt install \
    brightnessctl \
    foot \
    gammastep \
    gdm3 \
    grim slurp \
    pipewire-pulse \
    sway \
    swayidle \
    swaylock \
    wdisplays \
    wev \
    wireplumber \
    wlr-randr \
    xdg-desktop-portal-wlr
And did some of tweaks in my $HOME, mostly dealing with my esoteric systemd startup sequence, which you won't have to deal with if you are not a fan.

Why switch? I originally held back from migrating to Wayland: it seemed like a complicated endeavor hardly worth the cost. It also didn't seem actually ready. But after reading this blurb on LWN, I decided to at least document the situation here. The actual quote that convinced me it might be worth it was:
It s amazing. I have never experienced gaming on Linux that looked this smooth in my life.
... I'm not a gamer, but I do care about latency. The longer version is worth a read as well. The point here is not to bash one side or the other, or even do a thorough comparison. I start with the premise that Xorg is likely going away in the future and that I will need to adapt some day. In fact, the last major Xorg release (21.1, October 2021) is rumored to be the last ("just like the previous release...", that said, minor releases are still coming out, e.g. 21.1.4). Indeed, it seems even core Xorg people have moved on to developing Wayland, or at least Xwayland, which was spun off it its own source tree. X, or at least Xorg, in in maintenance mode and has been for years. Granted, the X Window System is getting close to forty years old at this point: it got us amazingly far for something that was designed around the time the first graphical interface. Since Mac and (especially?) Windows released theirs, they have rebuilt their graphical backends numerous times, but UNIX derivatives have stuck on Xorg this entire time, which is a testament to the design and reliability of X. (Or our incapacity at developing meaningful architectural change across the entire ecosystem, take your pick I guess.) What pushed me over the edge is that I had some pretty bad driver crashes with Xorg while screen sharing under Firefox, in Debian bookworm (around November 2022). The symptom would be that the UI would completely crash, reverting to a text-only console, while Firefox would keep running, audio and everything still working. People could still see my screen, but I couldn't, of course, let alone interact with it. All processes still running, including Xorg. (And no, sorry, I haven't reported that bug, maybe I should have, and it's actually possible it comes up again in Wayland, of course. But at first, screen sharing didn't work of course, so it's coming a much further way. After making screen sharing work, though, the bug didn't occur again, so I consider this a Xorg-specific problem until further notice.) There were also frustrating glitches in the UI, in general. I actually had to setup a compositor alongside i3 to make things bearable at all. Video playback in a window was laggy, sluggish, and out of sync. Wayland fixed all of this.

Wayland equivalents This section documents each tool I have picked as an alternative to the current Xorg tool I am using for the task at hand. It also touches on other alternatives and how the tool was configured. Note that this list is based on the series of tools I use in desktop. TODO: update desktop with the following when done, possibly moving old configs to a ?xorg archive.

Window manager: i3 sway This seems like kind of a no-brainer. Sway is around, it's feature-complete, and it's in Debian. I'm a bit worried about the "Drew DeVault community", to be honest. There's a certain aggressiveness in the community I don't like so much; at least an open hostility towards more modern UNIX tools like containers and systemd that make it hard to do my work while interacting with that community. I'm also concern about the lack of unit tests and user manual for Sway. The i3 window manager has been designed by a fellow (ex-)Debian developer I have a lot of respect for (Michael Stapelberg), partly because of i3 itself, but also working with him on other projects. Beyond the characters, i3 has a user guide, a code of conduct, and lots more documentation. It has a test suite. Sway has... manual pages, with the homepage just telling users to use man -k sway to find what they need. I don't think we need that kind of elitism in our communities, to put this bluntly. But let's put that aside: Sway is still a no-brainer. It's the easiest thing to migrate to, because it's mostly compatible with i3. I had to immediately fix those resources to get a minimal session going:
i3 Sway note
set_from_resources set no support for X resources, naturally
new_window pixel 1 default_border pixel 1 actually supported in i3 as well
That's it. All of the other changes I had to do (and there were actually a lot) were all Wayland-specific changes, not Sway-specific changes. For example, use brightnessctl instead of xbacklight to change the backlight levels. See a copy of my full sway/config for details. Other options include:
  • dwl: tiling, minimalist, dwm for Wayland, not in Debian
  • Hyprland: tiling, fancy animations, not in Debian
  • Qtile: tiling, extensible, in Python, not in Debian (1015267)
  • river: Zig, stackable, tagging, not in Debian (1006593)
  • velox: inspired by xmonad and dwm, not in Debian
  • vivarium: inspired by xmonad, not in Debian

Status bar: py3status waybar I have invested quite a bit of effort in setting up my status bar with py3status. It supports Sway directly, and did not actually require any change when migrating to Wayland. Unfortunately, I had trouble making nm-applet work. Based on this nm-applet.service, I found that you need to pass --indicator for it to show up at all. In theory, tray icon support was merged in 1.5, but in practice there are still several limitations, like icons not clickable. Also, on startup, nm-applet --indicator triggers this error in the Sway logs:
nov 11 22:34:12 angela sway[298938]: 00:49:42.325 [INFO] [swaybar/tray/host.c:24] Registering Status Notifier Item ':1.47/org/ayatana/NotificationItem/nm_applet'
nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet IconPixmap: No such property  IconPixmap 
nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet AttentionIconPixmap: No such property  AttentionIconPixmap 
nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet ItemIsMenu: No such property  ItemIsMenu 
nov 11 22:36:10 angela sway[313419]: info: fcft.c:838: /usr/share/fonts/truetype/dejavu/DejaVuSans.ttf: size=24.00pt/32px, dpi=96.00
... but that seems innocuous. The tray icon displays but is not clickable. Note that there is currently (November 2022) a pull request to hook up a "Tray D-Bus Menu" which, according to Reddit might fix this, or at least be somewhat relevant. If you don't see the icon, check the bar.tray_output property in the Sway config, try: tray_output *. The non-working tray was the biggest irritant in my migration. I have used nmtui to connect to new Wifi hotspots or change connection settings, but that doesn't support actions like "turn off WiFi". I eventually fixed this by switching from py3status to waybar, which was another yak horde shaving session, but ultimately, it worked.

Web browser: Firefox Firefox has had support for Wayland for a while now, with the team enabling it by default in nightlies around January 2022. It's actually not easy to figure out the state of the port, the meta bug report is still open and it's huge: it currently (Sept 2022) depends on 76 open bugs, it was opened twelve (2010) years ago, and it's still getting daily updates (mostly linking to other tickets). Firefox 106 presumably shipped with "Better screen sharing for Windows and Linux Wayland users", but I couldn't quite figure out what those were. TL;DR: echo MOZ_ENABLE_WAYLAND=1 >> ~/.config/environment.d/firefox.conf && apt install xdg-desktop-portal-wlr

How to enable it Firefox depends on this silly variable to start correctly under Wayland (otherwise it starts inside Xwayland and looks fuzzy and fails to screen share):
MOZ_ENABLE_WAYLAND=1 firefox
To make the change permanent, many recipes recommend adding this to an environment startup script:
if [ "$XDG_SESSION_TYPE" == "wayland" ]; then
    export MOZ_ENABLE_WAYLAND=1
fi
At least that's the theory. In practice, Sway doesn't actually run any startup shell script, so that can't possibly work. Furthermore, XDG_SESSION_TYPE is not actually set when starting Sway from gdm3 which I find really confusing, and I'm not the only one. So the above trick doesn't actually work, even if the environment (XDG_SESSION_TYPE) is set correctly, because we don't have conditionals in environment.d(5). (Note that systemd.environment-generator(7) do support running arbitrary commands to generate environment, but for some some do not support user-specific configuration files... Even then it may be a solution to have a conditional MOZ_ENABLE_WAYLAND environment, but I'm not sure it would work because ordering between those two isn't clear: maybe the XDG_SESSION_TYPE wouldn't be set just yet...) At first, I made this ridiculous script to workaround those issues. Really, it seems to me Firefox should just parse the XDG_SESSION_TYPE variable here... but then I realized that Firefox works fine in Xorg when the MOZ_ENABLE_WAYLAND is set. So now I just set that variable in environment.d and It Just Works :
MOZ_ENABLE_WAYLAND=1

Screen sharing Out of the box, screen sharing doesn't work until you install xdg-desktop-portal-wlr or similar (e.g. xdg-desktop-portal-gnome on GNOME). I had to reboot for the change to take effect. Without those tools, it shows the usual permission prompt with "Use operating system settings" as the only choice, but when we accept... nothing happens. After installing the portals, it actualyl works, and works well! This was tested in Debian bookworm/testing with Firefox ESR 102 and Firefox 106. Major caveat: we can only share a full screen, we can't currently share just a window. The major upside to that is that, by default, it streams only one output which is actually what I want most of the time! See the screencast compatibility for more information on what is supposed to work. This is actually a huge improvement over the situation in Xorg, where Firefox can only share a window or all monitors, which led me to use Chromium a lot for video-conferencing. With this change, in other words, I will not need Chromium for anything anymore, whoohoo! If slurp, wofi, or bemenu are installed, one of them will be used to pick the monitor to share, which effectively acts as some minimal security measure. See xdg-desktop-portal-wlr(1) for how to configure that.

Side note: Chrome fails to share a full screen I was still using Google Chrome (or, more accurately, Debian's Chromium package) for some videoconferencing. It's mainly because Chromium was the only browser which will allow me to share only one of my two monitors, which is extremely useful. To start chrome with the Wayland backend, you need to use:
chromium  -enable-features=UseOzonePlatform -ozone-platform=wayland
If it shows an ugly gray border, check the Use system title bar and borders setting. It can do some screensharing. Sharing a window and a tab seems to work, but sharing a full screen doesn't: it's all black. Maybe not ready for prime time. And since Firefox can do what I need under Wayland now, I will not need to fight with Chromium to work under Wayland:
apt purge chromium
Note that a similar fix was necessary for Signal Desktop, see this commit. Basically you need to figure out a way to pass those same flags to signal:
--enable-features=WaylandWindowDecorations --ozone-platform-hint=auto

Email: notmuch See Emacs, below.

File manager: thunar Unchanged.

News: feed2exec, gnus See Email, above, or Emacs in Editor, below.

Editor: Emacs okay-ish Emacs is being actively ported to Wayland. According to this LWN article, the first (partial, to Cairo) port was done in 2014 and a working port (to GTK3) was completed in 2021, but wasn't merged until late 2021. That is: after Emacs 28 was released (April 2022). So we'll probably need to wait for Emacs 29 to have native Wayland support in Emacs, which, in turn, is unlikely to arrive in time for the Debian bookworm freeze. There are, however, unofficial builds for both Emacs 28 and 29 provided by spwhitton which may provide native Wayland support. I tested the snapshot packages and they do not quite work well enough. First off, they completely take over the builtin Emacs they hijack the $PATH in /etc! and certain things are simply not working in my setup. For example, this hook never gets ran on startup:
(add-hook 'after-init-hook 'server-start t) 
Still, like many X11 applications, Emacs mostly works fine under Xwayland. The clipboard works as expected, for example. Scaling is a bit of an issue: fonts look fuzzy. I have heard anecdotal evidence of hard lockups with Emacs running under Xwayland as well, but haven't experienced any problem so far. I did experience a Wayland crash with the snapshot version however. TODO: look again at Wayland in Emacs 29.

Backups: borg Mostly irrelevant, as I do not use a GUI.

Color theme: srcery, redshift gammastep I am keeping Srcery as a color theme, in general. Redshift is another story: it has no support for Wayland out of the box, but it's apparently possible to apply a hack on the TTY before starting Wayland, with:
redshift -m drm -PO 3000
This tip is from the arch wiki which also has other suggestions for Wayland-based alternatives. Both KDE and GNOME have their own "red shifters", and for wlroots-based compositors, they (currently, Sept. 2022) list the following alternatives: I configured gammastep with a simple gammastep.service file associated with the sway-session.target.

Display manager: lightdm gdm3 Switched because lightdm failed to start sway:
nov 16 16:41:43 angela sway[843121]: 00:00:00.002 [ERROR] [wlr] [libseat] [common/terminal.c:162] Could not open target tty: Permission denied
Possible alternatives:

Terminal: xterm foot One of the biggest question mark in this transition was what to do about Xterm. After writing two articles about terminal emulators as a professional journalist, decades of working on the terminal, and probably using dozens of different terminal emulators, I'm still not happy with any of them. This is such a big topic that I actually have an entire blog post specifically about this. For starters, using xterm under Xwayland works well enough, although the font scaling makes things look a bit too fuzzy. I have also tried foot: it ... just works! Fonts are much crisper than Xterm and Emacs. URLs are not clickable but the URL selector (control-shift-u) is just plain awesome (think "vimperator" for the terminal). There's cool hack to jump between prompts. Copy-paste works. True colors work. The word-wrapping is excellent: it doesn't lose one byte. Emojis are nicely sized and colored. Font resize works. There's even scroll back search (control-shift-r). Foot went from a question mark to being a reason to switch to Wayland, just for this little goodie, which says a lot about the quality of that software. The selection clicks are a not quite what I would expect though. In rxvt and others, you have the following patterns:
  • single click: reset selection, or drag to select
  • double: select word
  • triple: select quotes or line
  • quadruple: select line
I particularly find the "select quotes" bit useful. It seems like foot just supports double and triple clicks, with word and line selected. You can select a rectangle with control,. It correctly extends the selection word-wise with right click if double-click was first used. One major problem with Foot is that it's a new terminal, with its own termcap entry. Support for foot was added to ncurses in the 20210731 release, which was shipped after the current Debian stable release (Debian bullseye, which ships 6.2+20201114-2). A workaround for this problem is to install the foot-terminfo package on the remote host, which is available in Debian stable. This should eventually resolve itself, as Debian bookworm has a newer version. Note that some corrections were also shipped in the 20211113 release, but that is also shipped in Debian bookworm. That said, I am almost certain I will have to revert back to xterm under Xwayland at some point in the future. Back when I was using GNOME Terminal, it would mostly work for everything until I had to use the serial console on a (HP ProCurve) network switch, which have a fancy TUI that was basically unusable there. I fully expect such problems with foot, or any other terminal than xterm, for that matter. The foot wiki has good troubleshooting instructions as well. Update: I did find one tiny thing to improve with foot, and it's the default logging level which I found pretty verbose. After discussing it with the maintainer on IRC, I submitted this patch to tweak it, which I described like this on Mastodon:
today's reason why i will go to hell when i die (TRWIWGTHWID?): a 600-word, 63 lines commit log for a one line change: https://codeberg.org/dnkl/foot/pulls/1215
It's Friday.

Launcher: rofi rofi?? rofi does not support Wayland. There was a rather disgraceful battle in the pull request that led to the creation of a fork (lbonn/rofi), so it's unclear how that will turn out. Given how relatively trivial problem space is, there is of course a profusion of options:
Tool In Debian Notes
alfred yes general launcher/assistant tool
bemenu yes, bookworm+ inspired by dmenu
cerebro no Javascript ... uh... thing
dmenu-wl no fork of dmenu, straight port to Wayland
Fuzzel ITP 982140 dmenu/drun replacement, app icon overlay
gmenu no drun replacement, with app icons
kickoff no dmenu/run replacement, fuzzy search, "snappy", history, copy-paste, Rust
krunner yes KDE's runner
mauncher no dmenu/drun replacement, math
nwg-launchers no dmenu/drun replacement, JSON config, app icons, nwg-shell project
Onagre no rofi/alfred inspired, multiple plugins, Rust
menu no dmenu/drun rewrite
Rofi (lbonn's fork) no see above
sirula no .desktop based app launcher
Ulauncher ITP 949358 generic launcher like Onagre/rofi/alfred, might be overkill
tofi yes, bookworm+ dmenu/drun replacement, C
wmenu no fork of dmenu-wl, but mostly a rewrite
Wofi yes dmenu/drun replacement, not actively maintained
yofi no dmenu/drun replacement, Rust
The above list comes partly from https://arewewaylandyet.com/ and awesome-wayland. It is likely incomplete. I have read some good things about bemenu, fuzzel, and wofi. A particularly tricky option is that my rofi password management depends on xdotool for some operations. At first, I thought this was just going to be (thankfully?) impossible, because we actually like the idea that one app cannot send keystrokes to another. But it seems there are actually alternatives to this, like wtype or ydotool, the latter which requires root access. wl-ime-type does that through the input-method-unstable-v2 protocol (sample emoji picker, but is not packaged in Debian. As it turns out, wtype just works as expected, and fixing this was basically a two-line patch. Another alternative, not in Debian, is wofi-pass. The other problem is that I actually heavily modified rofi. I use "modis" which are not actually implemented in wofi or tofi, so I'm left with reinventing those wheels from scratch or using the rofi + wayland fork... It's really too bad that fork isn't being reintegrated... For now, I'm actually still using rofi under Xwayland. The main downside is that fonts are fuzzy, but it otherwise just works. Note that wlogout could be a partial replacement (just for the "power menu").

Image viewers: geeqie ? I'm not very happy with geeqie in the first place, and I suspect the Wayland switch will just make add impossible things on top of the things I already find irritating (Geeqie doesn't support copy-pasting images). In practice, Geeqie doesn't seem to work so well under Wayland. The fonts are fuzzy and the thumbnail preview just doesn't work anymore (filed as Debian bug 1024092). It seems it also has problems with scaling. Alternatives: See also this list and that list for other list of image viewers, not necessarily ported to Wayland. TODO: pick an alternative to geeqie, nomacs would be gorgeous if it wouldn't be basically abandoned upstream (no release since 2020), has an unpatched CVE-2020-23884 since July 2020, does bad vendoring, and is in bad shape in Debian (4 minor releases behind). So for now I'm still grumpily using Geeqie.

Media player: mpv, gmpc / sublime This is basically unchanged. mpv seems to work fine under Wayland, better than Xorg on my new laptop (as mentioned in the introduction), and that before the version which improves Wayland support significantly, by bringing native Pipewire support and DMA-BUF support. gmpc is more of a problem, mainly because it is abandoned. See 2022-08-22-gmpc-alternatives for the full discussion, one of the alternatives there will likely support Wayland. Finally, I might just switch to sublime-music instead... In any case, not many changes here, thankfully.

Screensaver: xsecurelock swaylock I was previously using xss-lock and xsecurelock as a screensaver, with xscreensaver "hacks" as a backend for xsecurelock. The basic screensaver in Sway seems to be built with swayidle and swaylock. It's interesting because it's the same "split" design as xss-lock and xsecurelock. That, unfortunately, does not include the fancy "hacks" provided by xscreensaver, and that is unlikely to be implemented upstream. Other alternatives include gtklock and waylock (zig), which do not solve that problem either. It looks like swaylock-plugin, a swaylock fork, which at least attempts to solve this problem, although not directly using the real xscreensaver hacks. swaylock-effects is another attempt at this, but it only adds more effects, it doesn't delegate the image display. Other than that, maybe it's time to just let go of those funky animations and just let swaylock do it's thing, which is display a static image or just a black screen, which is fine by me. In the end, I am just using swayidle with a configuration based on the systemd integration wiki page but with additional tweaks from this service, see the resulting swayidle.service file. Interestingly, damjan also has a service for swaylock itself, although it's not clear to me what its purpose is...

Screenshot: maim grim, pubpaste I'm a heavy user of maim (and a package uploader in Debian). It looks like the direct replacement to maim (and slop) is grim (and slurp). There's also swappy which goes on top of grim and allows preview/edit of the resulting image, nice touch (not in Debian though). See also awesome-wayland screenshots for other alternatives: there are many, including X11 tools like Flameshot that also support Wayland. One key problem here was that I have my own screenshot / pastebin software which will needed an update for Wayland as well. That, thankfully, meant actually cleaning up a lot of horrible code that involved calling xterm and xmessage for user interaction. Now, pubpaste uses GTK for prompts and looks much better. (And before anyone freaks out, I already had to use GTK for proper clipboard support, so this isn't much of a stretch...)

Screen recorder: simplescreenrecorder wf-recorder In Xorg, I have used both peek or simplescreenrecorder for screen recordings. The former will work in Wayland, but has no sound support. The latter has a fork with Wayland support but it is limited and buggy ("doesn't support recording area selection and has issues with multiple screens"). It looks like wf-recorder will just do everything correctly out of the box, including audio support (with --audio, duh). It's also packaged in Debian. One has to wonder how this works while keeping the "between app security" that Wayland promises, however... Would installing such a program make my system less secure? Many other options are available, see the awesome Wayland screencasting list.

RSI: workrave nothing? Workrave has no support for Wayland. activity watch is a time tracker alternative, but is not a RSI watcher. KDE has rsiwatcher, but that's a bit too much on the heavy side for my taste. SafeEyes looks like an alternative at first, but it has many issues under Wayland (escape doesn't work, idle doesn't work, it just doesn't work really). timekpr-next could be an alternative as well, and has support for Wayland. I am also considering just abandoning workrave, even if I stick with Xorg, because it apparently introduces significant latency in the input pipeline. And besides, I've developed a pretty unhealthy alert fatigue with Workrave. I have used the program for so long that my fingers know exactly where to click to dismiss those warnings very effectively. It makes my work just more irritating, and doesn't fix the fundamental problem I have with computers.

Other apps This is a constantly changing list, of course. There's a bit of a "death by a thousand cuts" in migrating to Wayland because you realize how many things you were using are tightly bound to X.
  • .Xresources - just say goodbye to that old resource system, it was used, in my case, only for rofi, xterm, and ... Xboard!?
  • keyboard layout switcher: built-in to Sway since 2017 (PR 1505, 1.5rc2+), requires a small configuration change, see this answer as well, looks something like this command:
     swaymsg input 0:0:X11_keyboard xkb_layout de
    
    or using this config:
     input *  
         xkb_layout "ca,us"
         xkb_options "grp:sclk_toggle"
      
    
    That works refreshingly well, even better than in Xorg, I must say. swaykbdd is an alternative that supports per-window layouts (in Debian).
  • wallpaper: currently using feh, will need a replacement, TODO: figure out something that does, like feh, a random shuffle. swaybg just loads a single image, duh. oguri might be a solution, but unmaintained, used here, not in Debian. wallutils is another option, also not in Debian. For now I just don't have a wallpaper, the background is a solid gray, which is better than Xorg's default (which is whatever crap was left around a buffer by the previous collection of programs, basically)
  • notifications: currently using dunst in some places, which works well in both Xorg and Wayland, not a blocker, salut a possible alternative (not in Debian), damjan uses mako. TODO: install dunst everywhere
  • notification area: I had trouble making nm-applet work. based on this nm-applet.service, I found that you need to pass --indicator. In theory, tray icon support was merged in 1.5, but in practice there are still several limitations, like icons not clickable. On startup, nm-applet --indicator triggers this error in the Sway logs:
     nov 11 22:34:12 angela sway[298938]: 00:49:42.325 [INFO] [swaybar/tray/host.c:24] Registering Status Notifier Item ':1.47/org/ayatana/NotificationItem/nm_applet'
     nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet IconPixmap: No such property  IconPixmap 
     nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet AttentionIconPixmap: No such property  AttentionIconPixmap 
     nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet ItemIsMenu: No such property  ItemIsMenu 
     nov 11 22:36:10 angela sway[313419]: info: fcft.c:838: /usr/share/fonts/truetype/dejavu/DejaVuSans.ttf: size=24.00pt/32px, dpi=96.00
    
    ... but it seems innocuous. The tray icon displays but, as stated above, is not clickable. If you don't see the icon, check the bar.tray_output property in the Sway config, try: tray_output *. Note that there is currently (November 2022) a pull request to hook up a "Tray D-Bus Menu" which, according to Reddit might fix this, or at least be somewhat relevant. This was the biggest irritant in my migration. I have used nmtui to connect to new Wifi hotspots or change connection settings, but that doesn't support actions like "turn off WiFi". I eventually fixed this by switching from py3status to waybar.
  • window switcher: in i3 I was using this bespoke i3-focus script, which doesn't work under Sway, swayr an option, not in Debian. So I put together this other bespoke hack from multiple sources, which works.
  • PDF viewer: currently using atril (which supports Wayland), could also just switch to zatura/mupdf permanently, see also calibre for a discussion on document viewers
See also this list of useful addons and this other list for other app alternatives.

More X11 / Wayland equivalents For all the tools above, it's not exactly clear what options exist in Wayland, or when they do, which one should be used. But for some basic tools, it seems the options are actually quite clear. If that's the case, they should be listed here:
X11 Wayland In Debian
arandr wdisplays yes
autorandr kanshi yes
xdotool wtype yes
xev wev yes
xlsclients swaymsg -t get_tree yes
xrandr wlr-randr yes
lswt is a more direct replacement for xlsclients but is not packaged in Debian. See also: Note that arandr and autorandr are not directly part of X. arewewaylandyet.com refers to a few alternatives. We suggest wdisplays and kanshi above (see also this service file) but wallutils can also do the autorandr stuff, apparently, and nwg-displays can do the arandr part. Neither are packaged in Debian yet. So I have tried wdisplays and it Just Works, and well. The UI even looks better and more usable than arandr, so another clean win from Wayland here. TODO: test kanshi as a autorandr replacement

Other issues

systemd integration I've had trouble getting session startup to work. This is partly because I had a kind of funky system to start my session in the first place. I used to have my whole session started from .xsession like this:
#!/bin/sh
. ~/.shenv
systemctl --user import-environment
exec systemctl --user start --wait xsession.target
But obviously, the xsession.target is not started by the Sway session. It seems to just start a default.target, which is really not what we want because we want to associate the services directly with the graphical-session.target, so that they don't start when logging in over (say) SSH. damjan on #debian-systemd showed me his sway-setup which features systemd integration. It involves starting a different session in a completely new .desktop file. That work was submitted upstream but refused on the grounds that "I'd rather not give a preference to any particular init system." Another PR was abandoned because "restarting sway does not makes sense: that kills everything". The work was therefore moved to the wiki. So. Not a great situation. The upstream wiki systemd integration suggests starting the systemd target from within Sway, which has all sorts of problems:
  • you don't get Sway logs anywhere
  • control groups are all messed up
I have done a lot of work trying to figure this out, but I remember that starting systemd from Sway didn't actually work for me: my previously configured systemd units didn't correctly start, and especially not with the right $PATH and environment. So I went down that rabbit hole and managed to correctly configure Sway to be started from the systemd --user session. I have partly followed the wiki but also picked ideas from damjan's sway-setup and xdbob's sway-services. Another option is uwsm (not in Debian). This is the config I have in .config/systemd/user/: I have also configured those services, but that's somewhat optional: You will also need at least part of my sway/config, which sends the systemd notification (because, no, Sway doesn't support any sort of readiness notification, that would be too easy). And you might like to see my swayidle-config while you're there. Finally, you need to hook this up somehow to the login manager. This is typically done with a desktop file, so drop sway-session.desktop in /usr/share/wayland-sessions and sway-user-service somewhere in your $PATH (typically /usr/bin/sway-user-service). The session then looks something like this:
$ systemd-cgls   head -101
Control group /:
-.slice
 user.slice (#472)
    user.invocation_id: bc405c6341de4e93a545bde6d7abbeec
    trusted.invocation_id: bc405c6341de4e93a545bde6d7abbeec
   user-1000.slice (#10072)
      user.invocation_id: 08f40f5c4bcd4fd6adfd27bec24e4827
      trusted.invocation_id: 08f40f5c4bcd4fd6adfd27bec24e4827
     user@1000.service   (#10156)
        user.delegate: 1
        trusted.delegate: 1
        user.invocation_id: 76bed72a1ffb41dca9bfda7bb174ef6b
        trusted.invocation_id: 76bed72a1ffb41dca9bfda7bb174ef6b
       session.slice (#10282)
         xdg-document-portal.service (#12248)
           9533 /usr/libexec/xdg-document-portal
           9542 fusermount3 -o rw,nosuid,nodev,fsname=portal,auto_unmount,subt 
         xdg-desktop-portal.service (#12211)
           9529 /usr/libexec/xdg-desktop-portal
         pipewire-pulse.service (#10778)
           6002 /usr/bin/pipewire-pulse
         wireplumber.service (#10519)
           5944 /usr/bin/wireplumber
         gvfs-daemon.service (#10667)
           5960 /usr/libexec/gvfsd
         gvfs-udisks2-volume-monitor.service (#10852)
           6021 /usr/libexec/gvfs-udisks2-volume-monitor
         at-spi-dbus-bus.service (#11481)
           6210 /usr/libexec/at-spi-bus-launcher
           6216 /usr/bin/dbus-daemon --config-file=/usr/share/defaults/at-spi2 
           6450 /usr/libexec/at-spi2-registryd --use-gnome-session
         pipewire.service (#10403)
           5940 /usr/bin/pipewire
         dbus.service (#10593)
           5946 /usr/bin/dbus-daemon --session --address=systemd: --nofork --n 
       background.slice (#10324)
         tracker-miner-fs-3.service (#10741)
           6001 /usr/libexec/tracker-miner-fs-3
       app.slice (#10240)
         xdg-permission-store.service (#12285)
           9536 /usr/libexec/xdg-permission-store
         gammastep.service (#11370)
           6197 gammastep
         dunst.service (#11958)
           7460 /usr/bin/dunst
         wterminal.service (#13980)
           69100 foot --title pop-up
           69101 /bin/bash
           77660 sudo systemd-cgls
           77661 head -101
           77662 wl-copy
           77663 sudo systemd-cgls
           77664 systemd-cgls
         syncthing.service (#11995)
           7529 /usr/bin/syncthing -no-browser -no-restart -logflags=0 --verbo 
           7537 /usr/bin/syncthing -no-browser -no-restart -logflags=0 --verbo 
         dconf.service (#10704)
           5967 /usr/libexec/dconf-service
         gnome-keyring-daemon.service (#10630)
           5951 /usr/bin/gnome-keyring-daemon --foreground --components=pkcs11 
         gcr-ssh-agent.service (#10963)
           6035 /usr/libexec/gcr-ssh-agent /run/user/1000/gcr
         swayidle.service (#11444)
           6199 /usr/bin/swayidle -w
         nm-applet.service (#11407)
           6198 /usr/bin/nm-applet --indicator
         wcolortaillog.service (#11518)
           6226 foot colortaillog
           6228 /bin/sh /home/anarcat/bin/colortaillog
           6230 sudo journalctl -f
           6233 ccze -m ansi
           6235 sudo journalctl -f
           6236 journalctl -f
         afuse.service (#10889)
           6051 /usr/bin/afuse -o mount_template=sshfs -o transform_symlinks - 
         gpg-agent.service (#13547)
           51662 /usr/bin/gpg-agent --supervised
           51719 scdaemon --multi-server
         emacs.service (#10926)
            6034 /usr/bin/emacs --fg-daemon
           33203 /usr/bin/aspell -a -m -d en --encoding=utf-8
         xdg-desktop-portal-gtk.service (#12322)
           9546 /usr/libexec/xdg-desktop-portal-gtk
         xdg-desktop-portal-wlr.service (#12359)
           9555 /usr/libexec/xdg-desktop-portal-wlr
         sway.service (#11037)
           6037 /usr/bin/sway
           6181 swaybar -b bar-0
           6209 py3status
           6309 /usr/bin/i3status -c /tmp/py3status_oy4ntfnq
           6969 Xwayland :0 -rootless -terminate -core -listen 29 -listen 30 - 
       init.scope (#10198)
         5909 /lib/systemd/systemd --user
         5911 (sd-pam)
     session-7.scope (#10440)
       5895 gdm-session-worker [pam/gdm-password]
       6028 /usr/libexec/gdm-wayland-session --register-session sway-user-serv 
[...]
I think that's pretty neat.

Environment propagation At first, my terminals and rofi didn't have the right $PATH, which broke a lot of my workflow. It's hard to tell exactly how Wayland gets started or where to inject environment. This discussion suggests a few alternatives and this Debian bug report discusses this issue as well. I eventually picked environment.d(5) since I already manage my user session with systemd, and it fixes a bunch of other problems. I used to have a .shenv that I had to manually source everywhere. The only problem with that approach is that it doesn't support conditionals, but that's something that's rarely needed.

Pipewire This is a whole topic onto itself, but migrating to Wayland also involves using Pipewire if you want screen sharing to work. You can actually keep using Pulseaudio for audio, that said, but that migration is actually something I've wanted to do anyways: Pipewire's design seems much better than Pulseaudio, as it folds in JACK features which allows for pretty neat tricks. (Which I should probably show in a separate post, because this one is getting rather long.) I first tried this migration in Debian bullseye, and it didn't work very well. Ardour would fail to export tracks and I would get into weird situations where streams would just drop mid-way. A particularly funny incident is when I was in a meeting and I couldn't hear my colleagues speak anymore (but they could) and I went on blabbering on my own for a solid 5 minutes until I realized what was going on. By then, people had tried numerous ways of letting me know that something was off, including (apparently) coughing, saying "hello?", chat messages, IRC, and so on, until they just gave up and left. I suspect that was also a Pipewire bug, but it could also have been that I muted the tab by error, as I recently learned that clicking on the little tiny speaker icon on a tab mutes that tab. Since the tab itself can get pretty small when you have lots of them, it's actually quite frequently that I mistakenly mute tabs. Anyways. Point is: I already knew how to make the migration, and I had already documented how to make the change in Puppet. It's basically:
apt install pipewire pipewire-audio-client-libraries pipewire-pulse wireplumber 
Then, as a regular user:
systemctl --user daemon-reload
systemctl --user --now disable pulseaudio.service pulseaudio.socket
systemctl --user --now enable pipewire pipewire-pulse
systemctl --user mask pulseaudio
An optional (but key, IMHO) configuration you should also make is to "switch on connect", which will make your Bluetooth or USB headset automatically be the default route for audio, when connected. In ~/.config/pipewire/pipewire-pulse.conf.d/autoconnect.conf:
context.exec = [
      path = "pactl"        args = "load-module module-always-sink"  
      path = "pactl"        args = "load-module module-switch-on-connect"  
    #  path = "/usr/bin/sh"  args = "~/.config/pipewire/default.pw"  
]
See the excellent as usual Arch wiki page about Pipewire for that trick and more information about Pipewire. Note that you must not put the file in ~/.config/pipewire/pipewire.conf (or pipewire-pulse.conf, maybe) directly, as that will break your setup. If you want to add to that file, first copy the template from /usr/share/pipewire/pipewire-pulse.conf first. So far I'm happy with Pipewire in bookworm, but I've heard mixed reports from it. I have high hopes it will become the standard media server for Linux in the coming months or years, which is great because I've been (rather boldly, I admit) on the record saying I don't like PulseAudio. Rereading this now, I feel it might have been a little unfair, as "over-engineered and tries to do too many things at once" applies probably even more to Pipewire than PulseAudio (since it also handles video dispatching). That said, I think Pipewire took the right approach by implementing existing interfaces like Pulseaudio and JACK. That way we're not adding a third (or fourth?) way of doing audio in Linux; we're just making the server better.

Keypress drops Sometimes I lose keyboard presses. This correlates with the following warning from Sway:
d c 06 10:36:31 curie sway[343384]: 23:32:14.034 [ERROR] [wlr] [libinput] event5  - SONiX USB Keyboard: client bug: event processing lagging behind by 37ms, your system is too slow 
... and corresponds to an open bug report in Sway. It seems the "system is too slow" should really be "your compositor is too slow" which seems to be the case here on this older system (curie). It doesn't happen often, but it does happen, particularly when a bunch of busy processes start in parallel (in my case: a linter running inside a container and notmuch new). The proposed fix for this in Sway is to gain real time privileges and add the CAP_SYS_NICE capability to the binary. We'll see how that goes in Debian once 1.8 gets released and shipped.

Improvements over i3

Tiling improvements There's a lot of improvements Sway could bring over using plain i3. There are pretty neat auto-tilers that could replicate the configurations I used to have in Xmonad or Awesome, see:

Display latency tweaks TODO: You can tweak the display latency in wlroots compositors with the max_render_time parameter, possibly getting lower latency than X11 in the end.

Sound/brightness changes notifications TODO: Avizo can display a pop-up to give feedback on volume and brightness changes. Not in Debian. Other alternatives include SwayOSD and sway-nc, also not in Debian.

Debugging tricks The xeyes (in the x11-apps package) will run in Wayland, and can actually be used to easily see if a given window is also in Wayland. If the "eyes" follow the cursor, the app is actually running in xwayland, so not natively in Wayland. Another way to see what is using Wayland in Sway is with the command:
swaymsg -t get_tree

Other documentation

Conclusion In general, this took me a long time, but it mostly works. The tray icon situation is pretty frustrating, but there's a workaround and I have high hopes it will eventually fix itself. I'm also actually worried about the DisplayLink support because I eventually want to be using this, but hopefully that's another thing that will hopefully fix itself before I need it.

A word on the security model I'm kind of worried about all the hacks that have been added to Wayland just to make things work. Pretty much everywhere we need to, we punched a hole in the security model: Wikipedia describes the security properties of Wayland as it "isolates the input and output of every window, achieving confidentiality, integrity and availability for both." I'm not sure those are actually realized in the actual implementation, because of all those holes punched in the design, at least in Sway. For example, apparently the GNOME compositor doesn't have the virtual-keyboard protocol, but they do have (another?!) text input protocol. Wayland does offer a better basis to implement such a system, however. It feels like the Linux applications security model lacks critical decision points in the UI, like the user approving "yes, this application can share my screen now". Applications themselves might have some of those prompts, but it's not mandatory, and that is worrisome.

6 November 2022

Dirk Eddelbuettel: RcppCCTZ 0.2.12 on CRAN: Maintenance

A new release 0.2.12 of RcppCCTZ is now on CRAN. RcppCCTZ uses Rcpp to bring CCTZ to R. CCTZ is a C++ library for translating between absolute and civil times using the rules of a time zone. In fact, it is two libraries. One for dealing with civil time: human-readable dates and times, and one for converting between between absolute and civil times via time zones. And while CCTZ is made by Google(rs), it is not an official Google product. The RcppCCTZ page has a few usage examples and details. This package was the first CRAN package to use CCTZ; by now several others packages (four the last time we counted) include its sources too. Not ideal, but beyond our control. This version adds support for NA values when parsing, and updates GitHub Action.

Changes in version 0.2.12 (2022-11-06)
  • Support NA values in numerical or character input
  • GitHub Actions were updated to checkout version 3.

Courtesy of my CRANberries, there is also a diffstat to the previous version. More details are at the RcppCCTZ page; code, issue tickets etc at the GitHub repository. If you like this or other open-source work I do, you can now sponsor me at GitHub.

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

Marco d'Itri: Using a custom domain as the Mastodon identity

I just did again the usual web search, and I have verified that Mastodon still does not support managing multiple domains on the same instance, and that there is still no way to migrate an account to a different instance without losing all posts (and more?). As much as I like the idea of a federated social network, open standards and so on, I do not think that it would be wise for me to spend time developing a social network identity on somebody else's instance which could disappear at any time. I have managed my own email server since the '90s, but I do not feel that the system administration effort required to maintain a private Mastodon instance would be justified at this point: there is not even a Debian package! Mastodon either needs to become much simpler to maintain or become much more socially important, and so far it is neither. Also, it would be wasteful to use so many computing resources for a single-user instance. While it is not ideal, for the time being I compromised by redirecting WebFinger requests for md@linux.it using this Apache configuration:
<Location /.well-known/host-meta>
  Header set Access-Control-Allow-Origin: "*"
  Header set Content-Type: "application/xrd+json; charset=utf-8"
  Header set Cache-Control: "max-age=86400"
</Location>
<Location /.well-known/webfinger>
  Header set Access-Control-Allow-Origin: "*"
  Header set Content-Type: "application/jrd+json; charset=utf-8"
  Header set Cache-Control: "max-age=86400"
</Location>
# WebFinger (https://www.rfc-editor.org/rfc/rfc7033)
RewriteMap lc int:tolower
RewriteMap unescape int:unescape
RewriteCond % REQUEST_URI  ^/\.well-known/webfinger$
RewriteCond $ lc:$ unescape:% QUERY_STRING  (?:^ &)resource=acct:([^&]+)@linux\.it(?:$ &)
RewriteRule .+ /home/soci/%1/public_html/webfinger.json [L,QSD]
# answer 404 to requests missing "acct:" or for domains != linux.it
RewriteCond % REQUEST_URI  ^/\.well-known/webfinger$
RewriteCond $ unescape:% QUERY_STRING  (?:^ &)resource=
RewriteRule .+ - [L,R=404]
# answer 400 to requests without the resource parameter
RewriteCond % REQUEST_URI  ^/\.well-known/webfinger$
RewriteRule .+ - [L,R=400]

Russ Allbery: Review: Matrix

Review: Matrix, by Lauren Groff
Publisher: Riverhead Books
Copyright: 2021
ISBN: 0-698-40513-7
Format: Kindle
Pages: 260
Marie is a royal bastardess, a product of rape no less, and entirely out of place in the court in Westminster, where she landed after being kicked off her mother's farm. She had run the farm since her mother's untimely death, but there was no way that her relatives would let her inherit. In court, Marie is too tall, too ugly, and too strange, raised by women who were said to carry the blood of the fairy M lusine. Eleanor of Aquitaine's solution to her unwanted house guest is a Papal commission. Marie is to become the prioress of an abbey. I am occasionally unpleasantly reminded of why I don't read very much literary fiction. It's immensely frustrating to read a book in which the author cares about entirely different things than the reader, and where the story beats all land wrong. This is literary historical fiction set in the 12th century. Marie is Marie de France, author of the lais about courtly love that are famous primarily due to their position as early sources for the legends of King Arthur. The lais are written on-screen very early in this book, but they disappear without any meaningful impact on the story. Matrix is, instead, about Shaftesbury Abbey and what it becomes during Marie's time as prioress and then abbess, following the theory that Marie de France was Mary of Shaftesbury. What I thought I was getting in this book, from numerous reviews and recommendations, was a story of unexpected competence: how a wild, unwanted child of seventeen lands at a dilapidated and starving abbey, entirely against her will, and then over the next sixty years transforms it into one of the richest abbeys in England. This does happen in this book, but Groff doesn't seem to care about the details of that transformation at all. Instead, Matrix takes the mimetic fiction approach of detailed and precise description of a few characters, with all of their flaws and complexities, and with all of the narrative's attention turned to how they are feeling and what they are seeing. It is also deeply, fully committed to a Great Man (or in this case a Great Woman) view of history. Marie is singular. The narrative follows her alone, she makes all the significant decisions, and the development of the abbey is determined by her apparently mystical visions. (In typical mimetic fashion, these are presented as real to her, and the novel takes no position on whether that reality is objective.) She builds spy networks, maneuvers through local and church politics, and runs the abbey like her personal kingdom. The tiny amount of this that is necessarily done by other people is attributed to Marie's ability to judge character. Other people's motives are simply steamrolled over and have no effect. Maddeningly, essentially all of this happens off-screen, and Groff is completely uninterested in the details of how any of it is accomplished. Marie decides to do something, the narrative skips forward a year, and it has happened. She decides to build something, and then it's built. She decides to collect the rents she's due, the novel gestures vaguely at how she's intimidating, and then everyone is happily paying up. She builds spy networks; who cares how? She maneuvers through crises of local and church politics that are vaguely alluded to, through techniques that are apparently too uninteresting to bother the reader with. Instead, the narrative focuses on two things: her deeply dysfunctional, parasocial relationship with Eleanor, and her tyrannical relationship with the other nuns. I suspect that Groff would strongly disagree with my characterization of both of those narratives, and that's the other half of my problem with this book. Marie is obsessed with and in love with Eleanor, a completely impossible love to even talk about, and therefore turns to courtly love from afar as a model into which she can fit her feelings. While this is the setup for a tragedy, it's a good idea for a story. But what undermined it for me is that Marie's obsession seems to be largely physical (she constantly dwells on Eleanor's beauty), and Eleanor is absolutely horrible to her in every way: condescending, contemptuous, dismissive, and completely uninterested. This does change a bit over the course of the book, but not enough to justify the crush that Marie maintains for this awful person through her entire life. And Eleanor is the only person in the book who Marie treats like an equal. Everyone else is a subordinate, a daughter, a charge, a servant, or a worker. The nuns of the abbey prosper under her rule, so Marie has ample reason to justify this to herself, but no one else's opinions or beliefs matter to her in any significant way. The closest anyone can come to friendship is to be reliably obedient, perhaps after some initial objections that Marie overrules. Despite some quite good characterization of the other nuns, none of the other characters get to do anything. There is no delight in teamwork, sense of healthy community, or collaborative problem-solving. It's just all Marie, all the time, imposing her vision on the world both living and non-living through sheer force of will. This just isn't entertaining, at least for me. The writing might be beautiful, the descriptions detailed and effective, and the research clearly extensive, but I read books primarily for characters, I read characters primarily for their relationships, and these relationships are deeply, horribly unhealthy. They are not, to be clear, unrealistic (although I do think there's way too much chosen one in Marie and way too many problems that disappear off-camera); there are certainly people in the world with dysfunctional obsessive relationships, and there are charismatic people who overwhelm everyone around them. This is just not what I want to read about. You might think, with all I've said above, that I'm spoiling a lot of the book, but weirdly I don't think I am. Every pattern I mention above is well-established early in the novel. About the only thing that I'm spoiling is the hope that any of it is somehow going to change, a hope that I clung to for rather too long. This is a great setup for a book, and I wish it were written by a fantasy author instead of a literary author. Perhaps I'm being too harsh on literary fiction here, but I feel like fantasy authors are more likely to write for readers who want to see the growth sequence. If someone is going to change the world, I want to see how they changed the world. The mode of fantasy writing tends to think that what people do (and how they do it) is as interesting or more interesting than what they feel or what they perceive. If this idea, with the exact same level of (minor) mysticism and historic realism, without added magic, were written by, say, Guy Gavriel Kay or Nicola Griffith, it would be a far different and, in my opinion, a much better book. In fact, Hild is part of this book written by Nicola Griffith, and it is a much better book. I have seen enough people rave about this book to know that this is a personal reaction that is not going to be shared by everyone, or possibly even most people. My theory is that this is due to the different reading protocols between literary fiction readers and fantasy readers. I put myself in the latter camp; if you prefer literary fiction, you may like this much better (and also I'm not sure you'll find my book reviews useful). I may be wrong, though; maybe there are fantasy readers who would like this. I will say that the sense of place is very strong and the writing has all the expected literary strengths of descriptiveness and rhythm. But, sadly, this was not at all my thing, and I'm irritated that I wasted time on it. Rating: 4 out of 10

5 November 2022

Dirk Eddelbuettel: RcppEigen 0.3.3.9.3 on CRAN: Maintenance

A new release 0.3.3.9.3 of RcppEigen arrived on CRAN moments ago (and just went to Debian). Eigen is a C++ template library for linear algebra: matrices, vectors, numerical solvers, and related algorithms. This update is again mostly maintenance. To accomodate one small aspect of the Fortran interface, we now require R 3.6.0 or later. Jonah Gabry spotted a really old typo and fixed it. The fastLm support code now uses the unabbreviated df.residual. We accomodated clang-15 in one signature as is common with many recent uploads, and also updated one aspect of GitHub Actions. And once again as we said for the last four releases:
One additional and recent change was the accomodation of a recent CRAN Policy change to not allow gcc or clang to mess with diagnostic messages. A word of caution: this may make your compilation of packages using RcppEigen very noisy so consider adding -Wno-ignored-attributes to the compiler flags added in your ~/.R/Makevars.
We still find this requirement rather annoying. Eigen is only usable if you set, say,
-Wno-deprecated-declarations -Wno-parentheses -Wno-ignored-attributes -Wno-unused-function
asoptions in~/.R/Makevars . But CRAN makes the rules. Maybe if a few of us gently and politely nudge them they may relent one day. One can only hope. The complete NEWS file entry follows.

Changes in RcppEigen version 0.3.3.9.3 (2022-11-04)
  • The dependency on R is now versioned to 3.6.0 or later for support for USE_FC_LEN_T from Fortran.
  • An old example typo was corrected (Jonah Gabry in #114).
  • The fastLm methods now reference df.residual by its full name (Closes #115).
  • A function prototype was updated for clang-15.
  • GitHub Actions were updated to checkout version 3.

Courtesy of CRANberries, there is also a diffstat report for the most recent release. If you like this or other open-source work I do, you can sponsor me at GitHub.

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

Anuradha Weeraman: Getting started with Linkerd

If you ve done anything in the Kubernetes space in recent years, you ve most likely come across the words Service Mesh . It s backed by a set of mature technologies that provides cross-cutting networking, security, infrastructure capabilities to be used by workloads running in Kubernetes in a manner that is transparent to the actual workload. This abstraction enables application developers to not worry about building in otherwise sophisticated capabilities for networking, routing, circuit-breaking and security, and simply rely on the services offered by the service mesh.In this post, I ll be covering Linkerd, which is an alternative to Istio. It has gone through a significant re-write when it transitioned from the JVM to a Go-based Control Plane and a Rust-based Data Plane a few years back and is now a part of the CNCF and is backed by Buoyant. It has proven itself widely for use in production workloads and has a healthy community and release cadence.It achieves this with a side-car container that communicates with a Linkerd control plane that allows central management of policy, telemetry, mutual TLS, traffic routing, shaping, retries, load balancing, circuit-breaking and other cross-cutting concerns before the traffic hits the container. This has made the task of implementing the application services much simpler as it is managed by container orchestrator and service mesh. I covered Istio in a prior post a few years back, and much of the content is still applicable for this post, if you d like to have a look.Here are the broad architectural components of Linkerd:
The components are separated into the control plane and the data plane.The control plane components live in its own namespace and consists of a controller that the Linkerd CLI interacts with via the Kubernetes API. The destination service is used for service discovery, TLS identity, policy on access control for inter-service communication and service profile information on routing, retries, timeouts. The identity service acts as the Certificate Authority which responds to Certificate Signing Requests (CSRs) from proxies for initialization and for service-to-service encrypted traffic. The proxy injector is an admission webhook that injects the Linkerd proxy side car and the init container automatically into a pod when the linkerd.io/inject: enabled is available on the namespace or workload.On the data plane side are two components. First, the init container, which is responsible for automatically forwarding incoming and outgoing traffic through the Linkerd proxy via iptables rules. Second, the Linkerd proxy, which is a lightweight micro-proxy written in Rust, is the data plane itself.I will be walking you through the setup of Linkerd (2.12.2 at the time of writing) on a Kubernetes cluster.Let s see what s running on the cluster currently. This assumes you have a cluster running and kubectl is installed and available on the PATH.
$ kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system calico-kube-controllers-59697b644f-7fsln 1/1 Running 2 (119m ago) 7d
kube-system calico-node-6ptsh 1/1 Running 2 (119m ago) 7d
kube-system calico-node-7x5j8 1/1 Running 2 (119m ago) 7d
kube-system calico-node-qlnf6 1/1 Running 2 (119m ago) 7d
kube-system coredns-565d847f94-79jlw 1/1 Running 2 (119m ago) 7d
kube-system coredns-565d847f94-fqwn4 1/1 Running 2 (119m ago) 7d
kube-system etcd-k8s-master 1/1 Running 2 (119m ago) 7d
kube-system kube-apiserver-k8s-master 1/1 Running 2 (119m ago) 7d
kube-system kube-controller-manager-k8s-master 1/1 Running 2 (119m ago) 7d
kube-system kube-proxy-4n9b7 1/1 Running 2 (119m ago) 7d
kube-system kube-proxy-k4rzv 1/1 Running 2 (119m ago) 7d
kube-system kube-proxy-lz2dd 1/1 Running 2 (119m ago) 7d
kube-system kube-scheduler-k8s-master 1/1 Running 2 (119m ago) 7d
The first step would be to setup the Linkerd CLI:
$ curl --proto '=https' --tlsv1.2 -sSfL https://run.linkerd.io/install   sh
On most systems, this should be sufficient to setup the CLI. You may need to restart your terminal to load the updated paths. If you have a non-standard configuration and linkerd is not found after the installation, add the following to your PATH to be able to find the cli:
export PATH=$PATH:~/.linkerd2/bin/
At this point, checking the version would give you the following:
$ linkerd version
Client version: stable-2.12.2
Server version: unavailable
Setting up Linkerd Control PlaneBefore installing Linkerd on the cluster, run the following step to check the cluster for pre-requisites:
$ linkerd check --pre
Linkerd core checks
===================
kubernetes-api
--------------
can initialize the client
can query the Kubernetes API
kubernetes-version
------------------
is running the minimum Kubernetes API version
is running the minimum kubectl version
pre-kubernetes-setup
--------------------
control plane namespace does not already exist
can create non-namespaced resources
can create ServiceAccounts
can create Services
can create Deployments
can create CronJobs
can create ConfigMaps
can create Secrets
can read Secrets
can read extension-apiserver-authentication configmap
no clock skew detected
linkerd-version
---------------
can determine the latest version
cli is up-to-date
Status check results are  
All the pre-requisites appear to be good right now, and so installation can proceed.The first step of the installation is to setup the Custom Resource Definitions (CRDs) that Linkerd requires. The linkerd cli only prints the resource YAMLs to standard output and does not create them directly in Kubernetes, so you would need to pipe the output to kubectl apply to create the resources in the cluster that you re working with.
$ linkerd install --crds   kubectl apply -f -
Rendering Linkerd CRDs...
Next, run linkerd install kubectl apply -f - to install the control plane.
customresourcedefinition.apiextensions.k8s.io/authorizationpolicies.policy.linkerd.io created
customresourcedefinition.apiextensions.k8s.io/httproutes.policy.linkerd.io created
customresourcedefinition.apiextensions.k8s.io/meshtlsauthentications.policy.linkerd.io created
customresourcedefinition.apiextensions.k8s.io/networkauthentications.policy.linkerd.io created
customresourcedefinition.apiextensions.k8s.io/serverauthorizations.policy.linkerd.io created
customresourcedefinition.apiextensions.k8s.io/servers.policy.linkerd.io created
customresourcedefinition.apiextensions.k8s.io/serviceprofiles.linkerd.io created
Next, install the Linkerd control plane components in the same manner, this time without the crds switch:
$ linkerd install   kubectl apply -f -       
namespace/linkerd created
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-identity created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-identity created
serviceaccount/linkerd-identity created
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-destination created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-destination created
serviceaccount/linkerd-destination created
secret/linkerd-sp-validator-k8s-tls created
validatingwebhookconfiguration.admissionregistration.k8s.io/linkerd-sp-validator-webhook-config created
secret/linkerd-policy-validator-k8s-tls created
validatingwebhookconfiguration.admissionregistration.k8s.io/linkerd-policy-validator-webhook-config created
clusterrole.rbac.authorization.k8s.io/linkerd-policy created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-destination-policy created
role.rbac.authorization.k8s.io/linkerd-heartbeat created
rolebinding.rbac.authorization.k8s.io/linkerd-heartbeat created
clusterrole.rbac.authorization.k8s.io/linkerd-heartbeat created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-heartbeat created
serviceaccount/linkerd-heartbeat created
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-proxy-injector created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-proxy-injector created
serviceaccount/linkerd-proxy-injector created
secret/linkerd-proxy-injector-k8s-tls created
mutatingwebhookconfiguration.admissionregistration.k8s.io/linkerd-proxy-injector-webhook-config created
configmap/linkerd-config created
secret/linkerd-identity-issuer created
configmap/linkerd-identity-trust-roots created
service/linkerd-identity created
service/linkerd-identity-headless created
deployment.apps/linkerd-identity created
service/linkerd-dst created
service/linkerd-dst-headless created
service/linkerd-sp-validator created
service/linkerd-policy created
service/linkerd-policy-validator created
deployment.apps/linkerd-destination created
cronjob.batch/linkerd-heartbeat created
deployment.apps/linkerd-proxy-injector created
service/linkerd-proxy-injector created
secret/linkerd-config-overrides created
Kubernetes will start spinning up the data plane components and you should see the following when you list the pods:
$ kubectl get pods -A
...
linkerd linkerd-destination-67b9cc8749-xqcbx 4/4 Running 0 69s
linkerd linkerd-identity-59b46789cc-ntfcx 2/2 Running 0 69s
linkerd linkerd-proxy-injector-7fc85556bf-vnvw6 1/2 Running 0 69s
The components are running in the new linkerd namespace.To verify the setup, run a check:
$ linkerd check
Linkerd core checks
===================
kubernetes-api
--------------
can initialize the client
can query the Kubernetes API
kubernetes-version
------------------
is running the minimum Kubernetes API version
is running the minimum kubectl version
linkerd-existence
-----------------
'linkerd-config' config map exists
heartbeat ServiceAccount exist
control plane replica sets are ready
no unschedulable pods
control plane pods are ready
cluster networks contains all pods
cluster networks contains all services
linkerd-config
--------------
control plane Namespace exists
control plane ClusterRoles exist
control plane ClusterRoleBindings exist
control plane ServiceAccounts exist
control plane CustomResourceDefinitions exist
control plane MutatingWebhookConfigurations exist
control plane ValidatingWebhookConfigurations exist
proxy-init container runs as root user if docker container runtime is used
linkerd-identity
----------------
certificate config is valid
trust anchors are using supported crypto algorithm
trust anchors are within their validity period
trust anchors are valid for at least 60 days
issuer cert is using supported crypto algorithm
issuer cert is within its validity period
issuer cert is valid for at least 60 days
issuer cert is issued by the trust anchor
linkerd-webhooks-and-apisvc-tls
-------------------------------
proxy-injector webhook has valid cert
proxy-injector cert is valid for at least 60 days
sp-validator webhook has valid cert
sp-validator cert is valid for at least 60 days
policy-validator webhook has valid cert
policy-validator cert is valid for at least 60 days
linkerd-version
---------------
can determine the latest version
cli is up-to-date
control-plane-version
---------------------
can retrieve the control plane version
control plane is up-to-date
control plane and cli versions match
linkerd-control-plane-proxy
---------------------------
control plane proxies are healthy
control plane proxies are up-to-date
control plane proxies and cli versions match
Status check results are  
Everything looks good.Setting up the Viz ExtensionAt this point, the required components for the service mesh are setup, but let s also install the viz extension, which provides a good visualization capabilities that will come in handy subsequently. Once again, linkerd uses the same pattern for installing the extension.
$ linkerd viz install   kubectl apply -f -
namespace/linkerd-viz created
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-viz-metrics-api created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-viz-metrics-api created
serviceaccount/metrics-api created
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-viz-prometheus created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-viz-prometheus created
serviceaccount/prometheus created
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-viz-tap created
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-viz-tap-admin created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-viz-tap created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-viz-tap-auth-delegator created
serviceaccount/tap created
rolebinding.rbac.authorization.k8s.io/linkerd-linkerd-viz-tap-auth-reader created
secret/tap-k8s-tls created
apiservice.apiregistration.k8s.io/v1alpha1.tap.linkerd.io created
role.rbac.authorization.k8s.io/web created
rolebinding.rbac.authorization.k8s.io/web created
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-viz-web-check created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-viz-web-check created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-viz-web-admin created
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-viz-web-api created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-viz-web-api created
serviceaccount/web created
server.policy.linkerd.io/admin created
authorizationpolicy.policy.linkerd.io/admin created
networkauthentication.policy.linkerd.io/kubelet created
server.policy.linkerd.io/proxy-admin created
authorizationpolicy.policy.linkerd.io/proxy-admin created
service/metrics-api created
deployment.apps/metrics-api created
server.policy.linkerd.io/metrics-api created
authorizationpolicy.policy.linkerd.io/metrics-api created
meshtlsauthentication.policy.linkerd.io/metrics-api-web created
configmap/prometheus-config created
service/prometheus created
deployment.apps/prometheus created
service/tap created
deployment.apps/tap created
server.policy.linkerd.io/tap-api created
authorizationpolicy.policy.linkerd.io/tap created
clusterrole.rbac.authorization.k8s.io/linkerd-tap-injector created
clusterrolebinding.rbac.authorization.k8s.io/linkerd-tap-injector created
serviceaccount/tap-injector created
secret/tap-injector-k8s-tls created
mutatingwebhookconfiguration.admissionregistration.k8s.io/linkerd-tap-injector-webhook-config created
service/tap-injector created
deployment.apps/tap-injector created
server.policy.linkerd.io/tap-injector-webhook created
authorizationpolicy.policy.linkerd.io/tap-injector created
networkauthentication.policy.linkerd.io/kube-api-server created
service/web created
deployment.apps/web created
serviceprofile.linkerd.io/metrics-api.linkerd-viz.svc.cluster.local created
serviceprofile.linkerd.io/prometheus.linkerd-viz.svc.cluster.local created
A few seconds later, you should see the following in your pod list:
$ kubectl get pods -A
...
linkerd-viz prometheus-b5865f776-w5ssf 1/2 Running 0 35s
linkerd-viz tap-64f5c8597b-rqgbk 2/2 Running 0 35s
linkerd-viz tap-injector-7c75cfff4c-wl9mx 2/2 Running 0 34s
linkerd-viz web-8c444745-jhzr5 2/2 Running 0 34s
The viz components live in the linkerd-viz namespace.You can now checkout the viz dashboard:
$ linkerd viz dashboard
Linkerd dashboard available at:
http://localhost:50750
Grafana dashboard available at:
http://localhost:50750/grafana
Opening Linkerd dashboard in the default browser
Opening in existing browser session.
The Meshed column indicates the workload that is currently integrated with the Linkerd control plane. As you can see, there are no application deployments right now that are running.Injecting the Linkerd Data Plane componentsThere are two ways to integrate Linkerd to the application containers:1 by manually injecting the Linkerd data plane components
2 by instructing Kubernetes to automatically inject the data plane componentsInject Linkerd data plane manuallyLet s try the first option. Below is a simple nginx-app that I will deploy into the cluster:
$ cat deploy.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
spec:
selector:
matchLabels:
app: nginx
replicas: 2
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:latest
ports:
- containerPort: 80
$ kubectl apply -f deploy.yaml
Back in the viz dashboard, I do see the workload deployed, but it isn t currently communicating with the Linkerd control plane, and so doesn t show any metrics, and the Meshed count is 0:
Looking at the Pod s deployment YAML, I can see that it only includes the nginx container:
$ kubectl get pod nginx-deployment-cd55c47f5-cgxw2 -o yaml
apiVersion: v1
kind: Pod
metadata:
annotations:
cni.projectcalico.org/containerID: aee0295dda906f7935ce5c150ae30360005f5330e98c75a550b7cc0d1532f529
cni.projectcalico.org/podIP: 172.16.36.89/32
cni.projectcalico.org/podIPs: 172.16.36.89/32
creationTimestamp: "2022-11-05T19:35:12Z"
generateName: nginx-deployment-cd55c47f5-
labels:
app: nginx
pod-template-hash: cd55c47f5
name: nginx-deployment-cd55c47f5-cgxw2
namespace: default
ownerReferences:
- apiVersion: apps/v1
blockOwnerDeletion: true
controller: true
kind: ReplicaSet
name: nginx-deployment-cd55c47f5
uid: b604f5c4-f662-4333-aaa0-bd1a2b8b08c6
resourceVersion: "22979"
uid: 8fe30214-491b-4753-9fb2-485b6341376c
spec:
containers:
- image: nginx:latest
imagePullPolicy: Always
name: nginx
ports:
- containerPort: 80
protocol: TCP
resources:
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: kube-api-access-2bt6z
readOnly: true
dnsPolicy: ClusterFirst
enableServiceLinks: true
nodeName: k8s-node1
preemptionPolicy: PreemptLowerPriority
priority: 0
restartPolicy: Always
schedulerName: default-scheduler
securityContext:
serviceAccount: default
serviceAccountName: default
terminationGracePeriodSeconds: 30
tolerations:
- effect: NoExecute
key: node.kubernetes.io/not-ready
operator: Exists
tolerationSeconds: 300
- effect: NoExecute
key: node.kubernetes.io/unreachable
operator: Exists
tolerationSeconds: 300
volumes:
- name: kube-api-access-2bt6z
projected:
defaultMode: 420
sources:
- serviceAccountToken:
expirationSeconds: 3607
path: token
- configMap:
items:
- key: ca.crt
path: ca.crt
name: kube-root-ca.crt
- downwardAPI:
items:
- fieldRef:
apiVersion: v1
fieldPath: metadata.namespace
path: namespace
status:
conditions:
- lastProbeTime: null
lastTransitionTime: "2022-11-05T19:35:12Z"
status: "True"
type: Initialized
- lastProbeTime: null
lastTransitionTime: "2022-11-05T19:35:16Z"
status: "True"
type: Ready
- lastProbeTime: null
lastTransitionTime: "2022-11-05T19:35:16Z"
status: "True"
type: ContainersReady
- lastProbeTime: null
lastTransitionTime: "2022-11-05T19:35:13Z"
status: "True"
type: PodScheduled
containerStatuses:
- containerID: containerd://f088f200315b44cbeed16499aba9b2d1396f9f81645e53b032d4bfa44166128a
image: docker.io/library/nginx:latest
imageID: docker.io/library/nginx@sha256:943c25b4b66b332184d5ba6bb18234273551593016c0e0ae906bab111548239f
lastState:
name: nginx
ready: true
restartCount: 0
started: true
state:
running:
startedAt: "2022-11-05T19:35:15Z"
hostIP: 192.168.2.216
phase: Running
podIP: 172.16.36.89
podIPs:
- ip: 172.16.36.89
qosClass: BestEffort
startTime: "2022-11-05T19:35:12Z"
Let s directly inject the linkerd data plane into this running container. We do this by retrieving the YAML of the deployment, piping it to linkerd cli to inject the necessary components and then piping to kubectl apply the changed resources.
$ kubectl get deploy nginx-deployment -o yaml   linkerd inject -   kubectl apply -f -
deployment "nginx-deployment" injected
deployment.apps/nginx-deployment configured
Back in the viz dashboard, the workload now is integrated into Linkerd control plane.
Looking at the updated Pod definition, we see a number of changes that the linkerd has injected that allows it to integrate with the control plane. Let s have a look:
$ kubectl get pod nginx-deployment-858bdd545b-55jpf -o yaml
apiVersion: v1
kind: Pod
metadata:
annotations:
cni.projectcalico.org/containerID: 1ec3d345f859be8ead0374a7e880bcfdb9ba74a121b220a6fccbd342ac4b7ea8
cni.projectcalico.org/podIP: 172.16.36.90/32
cni.projectcalico.org/podIPs: 172.16.36.90/32
linkerd.io/created-by: linkerd/proxy-injector stable-2.12.2
linkerd.io/inject: enabled
linkerd.io/proxy-version: stable-2.12.2
linkerd.io/trust-root-sha256: 354fe6f49331e8e03d8fb07808e00a3e145d2661181cbfec7777b41051dc8e22
viz.linkerd.io/tap-enabled: "true"
creationTimestamp: "2022-11-05T19:44:15Z"
generateName: nginx-deployment-858bdd545b-
labels:
app: nginx
linkerd.io/control-plane-ns: linkerd
linkerd.io/proxy-deployment: nginx-deployment
linkerd.io/workload-ns: default
pod-template-hash: 858bdd545b
name: nginx-deployment-858bdd545b-55jpf
namespace: default
ownerReferences:
- apiVersion: apps/v1
blockOwnerDeletion: true
controller: true
kind: ReplicaSet
name: nginx-deployment-858bdd545b
uid: 2e618972-aa10-4e35-a7dd-084853673a80
resourceVersion: "23820"
uid: 62f1857a-b701-4a19-8996-b5b605ff8488
spec:
containers:
- env:
- name: _pod_name
valueFrom:
fieldRef:
apiVersion: v1
fieldPath: metadata.name
- name: _pod_ns
valueFrom:
fieldRef:
apiVersion: v1
fieldPath: metadata.namespace
- name: _pod_nodeName
valueFrom:
fieldRef:
apiVersion: v1
fieldPath: spec.nodeName
- name: LINKERD2_PROXY_LOG
value: warn,linkerd=info
- name: LINKERD2_PROXY_LOG_FORMAT
value: plain
- name: LINKERD2_PROXY_DESTINATION_SVC_ADDR
value: linkerd-dst-headless.linkerd.svc.cluster.local.:8086
- name: LINKERD2_PROXY_DESTINATION_PROFILE_NETWORKS
value: 10.0.0.0/8,100.64.0.0/10,172.16.0.0/12,192.168.0.0/16
- name: LINKERD2_PROXY_POLICY_SVC_ADDR
value: linkerd-policy.linkerd.svc.cluster.local.:8090
- name: LINKERD2_PROXY_POLICY_WORKLOAD
value: $(_pod_ns):$(_pod_name)
- name: LINKERD2_PROXY_INBOUND_DEFAULT_POLICY
value: all-unauthenticated
- name: LINKERD2_PROXY_POLICY_CLUSTER_NETWORKS
value: 10.0.0.0/8,100.64.0.0/10,172.16.0.0/12,192.168.0.0/16
- name: LINKERD2_PROXY_INBOUND_CONNECT_TIMEOUT
value: 100ms
- name: LINKERD2_PROXY_OUTBOUND_CONNECT_TIMEOUT
value: 1000ms
- name: LINKERD2_PROXY_CONTROL_LISTEN_ADDR
value: 0.0.0.0:4190
- name: LINKERD2_PROXY_ADMIN_LISTEN_ADDR
value: 0.0.0.0:4191
- name: LINKERD2_PROXY_OUTBOUND_LISTEN_ADDR
value: 127.0.0.1:4140
- name: LINKERD2_PROXY_INBOUND_LISTEN_ADDR
value: 0.0.0.0:4143
- name: LINKERD2_PROXY_INBOUND_IPS
valueFrom:
fieldRef:
apiVersion: v1
fieldPath: status.podIPs
- name: LINKERD2_PROXY_INBOUND_PORTS
value: "80"
- name: LINKERD2_PROXY_DESTINATION_PROFILE_SUFFIXES
value: svc.cluster.local.
- name: LINKERD2_PROXY_INBOUND_ACCEPT_KEEPALIVE
value: 10000ms
- name: LINKERD2_PROXY_OUTBOUND_CONNECT_KEEPALIVE
value: 10000ms
- name: LINKERD2_PROXY_INBOUND_PORTS_DISABLE_PROTOCOL_DETECTION
value: 25,587,3306,4444,5432,6379,9300,11211
- name: LINKERD2_PROXY_DESTINATION_CONTEXT
value:
"ns":"$(_pod_ns)", "nodeName":"$(_pod_nodeName)"
- name: _pod_sa
valueFrom:
fieldRef:
apiVersion: v1
fieldPath: spec.serviceAccountName
- name: _l5d_ns
value: linkerd
- name: _l5d_trustdomain
value: cluster.local
- name: LINKERD2_PROXY_IDENTITY_DIR
value: /var/run/linkerd/identity/end-entity
- name: LINKERD2_PROXY_IDENTITY_TRUST_ANCHORS
value:
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
- name: LINKERD2_PROXY_IDENTITY_TOKEN_FILE
value: /var/run/secrets/tokens/linkerd-identity-token
- name: LINKERD2_PROXY_IDENTITY_SVC_ADDR
value: linkerd-identity-headless.linkerd.svc.cluster.local.:8080
- name: LINKERD2_PROXY_IDENTITY_LOCAL_NAME
value: $(_pod_sa).$(_pod_ns).serviceaccount.identity.linkerd.cluster.local
- name: LINKERD2_PROXY_IDENTITY_SVC_NAME
value: linkerd-identity.linkerd.serviceaccount.identity.linkerd.cluster.local
- name: LINKERD2_PROXY_DESTINATION_SVC_NAME
value: linkerd-destination.linkerd.serviceaccount.identity.linkerd.cluster.local
- name: LINKERD2_PROXY_POLICY_SVC_NAME
value: linkerd-destination.linkerd.serviceaccount.identity.linkerd.cluster.local
- name: LINKERD2_PROXY_TAP_SVC_NAME
value: tap.linkerd-viz.serviceaccount.identity.linkerd.cluster.local
image: cr.l5d.io/linkerd/proxy:stable-2.12.2
imagePullPolicy: IfNotPresent
lifecycle:
postStart:
exec:
command:
- /usr/lib/linkerd/linkerd-await
- --timeout=2m
livenessProbe:
failureThreshold: 3
httpGet:
path: /live
port: 4191
scheme: HTTP
initialDelaySeconds: 10
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 1
name: linkerd-proxy
ports:
- containerPort: 4143
name: linkerd-proxy
protocol: TCP
- containerPort: 4191
name: linkerd-admin
protocol: TCP
readinessProbe:
failureThreshold: 3
httpGet:
path: /ready
port: 4191
scheme: HTTP
initialDelaySeconds: 2
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 1
resources:
securityContext:
allowPrivilegeEscalation: false
readOnlyRootFilesystem: true
runAsUser: 2102
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: FallbackToLogsOnError
volumeMounts:
- mountPath: /var/run/linkerd/identity/end-entity
name: linkerd-identity-end-entity
- mountPath: /var/run/secrets/tokens
name: linkerd-identity-token
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: kube-api-access-9zpnn
readOnly: true
- image: nginx:latest
imagePullPolicy: Always
name: nginx
ports:
- containerPort: 80
protocol: TCP
resources:
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: kube-api-access-9zpnn
readOnly: true
dnsPolicy: ClusterFirst
enableServiceLinks: true
initContainers:
- args:
- --incoming-proxy-port
- "4143"
- --outgoing-proxy-port
- "4140"
- --proxy-uid
- "2102"
- --inbound-ports-to-ignore
- 4190,4191,4567,4568
- --outbound-ports-to-ignore
- 4567,4568
image: cr.l5d.io/linkerd/proxy-init:v2.0.0
imagePullPolicy: IfNotPresent
name: linkerd-init
resources:
limits:
cpu: 100m
memory: 20Mi
requests:
cpu: 100m
memory: 20Mi
securityContext:
allowPrivilegeEscalation: false
capabilities:
add:
- NET_ADMIN
- NET_RAW
privileged: false
readOnlyRootFilesystem: true
runAsNonRoot: true
runAsUser: 65534
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: FallbackToLogsOnError
volumeMounts:
- mountPath: /run
name: linkerd-proxy-init-xtables-lock
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: kube-api-access-9zpnn
readOnly: true
nodeName: k8s-node1
preemptionPolicy: PreemptLowerPriority
priority: 0
restartPolicy: Always
schedulerName: default-scheduler
securityContext:
serviceAccount: default
serviceAccountName: default
terminationGracePeriodSeconds: 30
tolerations:
- effect: NoExecute
key: node.kubernetes.io/not-ready
operator: Exists
tolerationSeconds: 300
- effect: NoExecute
key: node.kubernetes.io/unreachable
operator: Exists
tolerationSeconds: 300
volumes:
- name: kube-api-access-9zpnn
projected:
defaultMode: 420
sources:
- serviceAccountToken:
expirationSeconds: 3607
path: token
- configMap:
items:
- key: ca.crt
path: ca.crt
name: kube-root-ca.crt
- downwardAPI:
items:
- fieldRef:
apiVersion: v1
fieldPath: metadata.namespace
path: namespace
- emptyDir:
name: linkerd-proxy-init-xtables-lock
- emptyDir:
medium: Memory
name: linkerd-identity-end-entity
- name: linkerd-identity-token
projected:
defaultMode: 420
sources:
- serviceAccountToken:
audience: identity.l5d.io
expirationSeconds: 86400
path: linkerd-identity-token
status:
conditions:
- lastProbeTime: null
lastTransitionTime: "2022-11-05T19:44:16Z"
status: "True"
type: Initialized
- lastProbeTime: null
lastTransitionTime: "2022-11-05T19:44:19Z"
status: "True"
type: Ready
- lastProbeTime: null
lastTransitionTime: "2022-11-05T19:44:19Z"
status: "True"
type: ContainersReady
- lastProbeTime: null
lastTransitionTime: "2022-11-05T19:44:15Z"
status: "True"
type: PodScheduled
containerStatuses:
- containerID: containerd://62028867c48aaa726df48249a27c52cd8820cd33e8e5695ad0d322540924754e
image: cr.l5d.io/linkerd/proxy:stable-2.12.2
imageID: cr.l5d.io/linkerd/proxy@sha256:787db5055b2a46a3c4318ef3b632461261f81254c8e47bf4b9b8dab2c42575e4
lastState:
name: linkerd-proxy
ready: true
restartCount: 0
started: true
state:
running:
startedAt: "2022-11-05T19:44:16Z"
- containerID: containerd://8f8ce663c19360a7b6868ace68a4a5119f0b18cd57ffebcc2d19331274038381
image: docker.io/library/nginx:latest
imageID: docker.io/library/nginx@sha256:943c25b4b66b332184d5ba6bb18234273551593016c0e0ae906bab111548239f
lastState:
name: nginx
ready: true
restartCount: 0
started: true
state:
running:
startedAt: "2022-11-05T19:44:19Z"
hostIP: 192.168.2.216
initContainerStatuses:
- containerID: containerd://c0417ea9c8418ab296bf86077e81c5d8be06fe9b87390c138d1c5d7b73cc577c
image: cr.l5d.io/linkerd/proxy-init:v2.0.0
imageID: cr.l5d.io/linkerd/proxy-init@sha256:7d5e66b9e176b1ebbdd7f40b6385d1885e82c80a06f4c6af868247bb1dffe262
lastState:
name: linkerd-init
ready: true
restartCount: 0
state:
terminated:
containerID: containerd://c0417ea9c8418ab296bf86077e81c5d8be06fe9b87390c138d1c5d7b73cc577c
exitCode: 0
finishedAt: "2022-11-05T19:44:16Z"
reason: Completed
startedAt: "2022-11-05T19:44:15Z"
phase: Running
podIP: 172.16.36.90
podIPs:
- ip: 172.16.36.90
qosClass: Burstable
startTime: "2022-11-05T19:44:15Z"
At this point, the necessary components are setup for you to explore Linkerd further. You can also try out the jaeger and multicluster extensions, similar to the process of installing and using the viz extension and try out their capabilities.Inject Linkerd data plane automaticallyIn this approach, we shall we how to instruct Kubernetes to automatically inject the Linkerd data plane to workloads at deployment time.We can achieve this by adding the linkerd.io/inject annotation to the deployment descriptor which causes the proxy injector admission hook to execute and inject linkerd data plane components automatically at the time of deployment.
$ cat deploy.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
spec:
selector:
matchLabels:
app: nginx
replicas: 2
template:
metadata:
labels:
app: nginx
annotations:
linkerd.io/inject: enabled
spec:
containers:
- name: nginx
image: nginx:latest
ports:
- containerPort: 80
This annotation can also be specified at the namespace level to affect all the workloads within the namespace. Note that any resources created before the annotation was added to the namespace will require a rollout restart to trigger the injection of the Linkerd components.Uninstalling LinkerdNow that we have walked through the installation and setup process of Linkerd, let s also cover how to remove it from the infrastructure and go back to the state prior to its installation.The first step would be to remove extensions, such as viz.
$ linkerd viz uninstall   kubectl delete -f -
clusterrole.rbac.authorization.k8s.io "linkerd-linkerd-viz-metrics-api" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-linkerd-viz-prometheus" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-linkerd-viz-tap" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-linkerd-viz-tap-admin" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-linkerd-viz-web-api" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-linkerd-viz-web-check" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-tap-injector" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-viz-metrics-api" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-viz-prometheus" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-viz-tap" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-viz-tap-auth-delegator" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-viz-web-admin" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-viz-web-api" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-viz-web-check" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-tap-injector" deleted
role.rbac.authorization.k8s.io "web" deleted
rolebinding.rbac.authorization.k8s.io "linkerd-linkerd-viz-tap-auth-reader" deleted
rolebinding.rbac.authorization.k8s.io "web" deleted
apiservice.apiregistration.k8s.io "v1alpha1.tap.linkerd.io" deleted
mutatingwebhookconfiguration.admissionregistration.k8s.io "linkerd-tap-injector-webhook-config" deleted
namespace "linkerd-viz" deleted
authorizationpolicy.policy.linkerd.io "admin" deleted
authorizationpolicy.policy.linkerd.io "metrics-api" deleted
authorizationpolicy.policy.linkerd.io "proxy-admin" deleted
authorizationpolicy.policy.linkerd.io "tap" deleted
authorizationpolicy.policy.linkerd.io "tap-injector" deleted
server.policy.linkerd.io "admin" deleted
server.policy.linkerd.io "metrics-api" deleted
server.policy.linkerd.io "proxy-admin" deleted
server.policy.linkerd.io "tap-api" deleted
server.policy.linkerd.io "tap-injector-webhook" deleted
In order to uninstall the control plane, you would need to first uninject the Linkerd control plane components from any existing running pods by:
$ kubectl get deployments
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-deployment 2/2 2 2 10m
$ kubectl get deployment nginx-deployment -o yaml   linkerd uninject -   kubectl apply -f -
deployment "nginx-deployment" uninjected
deployment.apps/nginx-deployment configured
Now you can delete the control plane.
$ linkerd uninstall   kubectl delete -f -
clusterrole.rbac.authorization.k8s.io "linkerd-heartbeat" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-linkerd-destination" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-linkerd-identity" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-linkerd-proxy-injector" deleted
clusterrole.rbac.authorization.k8s.io "linkerd-policy" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-destination-policy" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-heartbeat" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-destination" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-identity" deleted
clusterrolebinding.rbac.authorization.k8s.io "linkerd-linkerd-proxy-injector" deleted
role.rbac.authorization.k8s.io "linkerd-heartbeat" deleted
rolebinding.rbac.authorization.k8s.io "linkerd-heartbeat" deleted
customresourcedefinition.apiextensions.k8s.io "authorizationpolicies.policy.linkerd.io" deleted
customresourcedefinition.apiextensions.k8s.io "httproutes.policy.linkerd.io" deleted
customresourcedefinition.apiextensions.k8s.io "meshtlsauthentications.policy.linkerd.io" deleted
customresourcedefinition.apiextensions.k8s.io "networkauthentications.policy.linkerd.io" deleted
customresourcedefinition.apiextensions.k8s.io "serverauthorizations.policy.linkerd.io" deleted
customresourcedefinition.apiextensions.k8s.io "servers.policy.linkerd.io" deleted
customresourcedefinition.apiextensions.k8s.io "serviceprofiles.linkerd.io" deleted
mutatingwebhookconfiguration.admissionregistration.k8s.io "linkerd-proxy-injector-webhook-config" deleted
validatingwebhookconfiguration.admissionregistration.k8s.io "linkerd-policy-validator-webhook-config" deleted
validatingwebhookconfiguration.admissionregistration.k8s.io "linkerd-sp-validator-webhook-config" deleted
namespace "linkerd" deleted
At this point we re back to the original state:
$ kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
default nginx-deployment-cd55c47f5-99xf2 1/1 Running 0 82s
default nginx-deployment-cd55c47f5-tt58t 1/1 Running 0 86s
kube-system calico-kube-controllers-59697b644f-7fsln 1/1 Running 2 (3h39m ago) 7d1h
kube-system calico-node-6ptsh 1/1 Running 2 (3h39m ago) 7d1h
kube-system calico-node-7x5j8 1/1 Running 2 (3h39m ago) 7d1h
kube-system calico-node-qlnf6 1/1 Running 2 (3h39m ago) 7d1h
kube-system coredns-565d847f94-79jlw 1/1 Running 2 (3h39m ago) 7d2h
kube-system coredns-565d847f94-fqwn4 1/1 Running 2 (3h39m ago) 7d2h
kube-system etcd-k8s-master 1/1 Running 2 (3h39m ago) 7d2h
kube-system kube-apiserver-k8s-master 1/1 Running 2 (3h39m ago) 7d2h
kube-system kube-controller-manager-k8s-master 1/1 Running 2 (3h39m ago) 7d2h
kube-system kube-proxy-4n9b7 1/1 Running 2 (3h39m ago) 7d2h
kube-system kube-proxy-k4rzv 1/1 Running 2 (3h39m ago) 7d2h
kube-system kube-proxy-lz2dd 1/1 Running 2 (3h39m ago) 7d2h
kube-system kube-scheduler-k8s-master 1/1 Running 2 (3h39m ago) 7d2h
I hope you find this useful to get you started on your journey with Linkerd. Head on over to the docs for more information, guides and best practices.

3 November 2022

Alastair McKinstry: New Planning and Environment Court will reform planning appeals pro...

New Planning and Environment Court will reform planning appeals process #GreensInGovernment The Green Party has fulfilled an important Programme for Government commitment following the cabinet's decision to establish a new division of the High Court to specialise in environmental and planning issues. This is a major reform that will allow planning law to operate in a more efficient and environmentally friendly manner. Steven Matthews TD, Green Party Spokesperson for Planning and Local Government, explained the aim of the new court; The goal is to ensure that our judicial system has the capacity to decide cases as quickly as possible within a growing and increasingly complex body of Irish and EU environmental law. Timely access to justice is a cornersto ne of the effective rule of law and an international legal commitment Ireland has entered under the Aarhus Convention. This is extremely pressing given the urgent need to ease the pressure on the housing system and develop the infrastructure we need to transition to a zero-carbon economy." The Green Party is committed to ensuring the new Court will have the resources to fulfil its role. The Government will pass new legislation to allow the number of judges to be increased and provide the necessary exchequer funding to pay for these judges. The new Court will hear all the cases currently taken by the High Court s Commercial Planning and Strategic Infrastructure Development List and other major environmental cases. This is likely to include all major infrastructure cases as well as many cases relating to EU Environmental Law such as Environmental Impact Assessment, Strategic Environmental Assessment, Birds/Habitats, the Water Framework Directive and the Industrial Emissions Directive.

Russ Allbery: Review: Carpe Jugulum

Review: Carpe Jugulum, by Terry Pratchett
Series: Discworld #23
Publisher: Harper
Copyright: 1998
Printing: May 2014
ISBN: 0-06-228014-7
Format: Mass market
Pages: 409
Carpe Jugulum is the 23rd Discworld novel and the 6th witches novel. I would not recommend reading it before Maskerade, which introduces Agnes. There are some spoilers for Wyrd Sisters, Lords and Ladies, and Maskerade in the setup here and hence in the plot description below. I don't think they matter that much, but if you're avoiding all spoilers for earlier books, you may want to skip over this one. (You're unlikely to want to read it before those books anyway.) It is time to name the child of the king of Lancre, and in a gesture of good will and modernization, he has invited his neighbors in Uberwald to attend. Given that those neighbors are vampires, an open invitation was perhaps not the wisest choice. Meanwhile, Granny Weatherwax's invitation has gone missing. On the plus side, that meant she was home to be summoned to the bedside of a pregnant woman who was kicked by a cow, where she makes the type of hard decision that Granny has been making throughout the series. On the minus side, the apparent snub seems to send her into a spiral of anger at the lack of appreciation. Points off right from the start for a plot based on a misunderstanding and a subsequent refusal of people to simply talk to each other. It is partly engineered, but still, it's a cheap and irritating plot. This is an odd book. The vampires (or vampyres, as the Count wants to use) think of themselves as modern and sophisticated, making a break from the past by attempting to overcome such traditional problems as burning up in the sunlight and fear of religious symbols and garlic. The Count has put his family through rigorous training and desensitization, deciding such traditional vulnerabilities are outdated things of the past. He has, however, kept the belief that vampires are at the top of a natural chain of being, humans are essentially cattle, and vampires naturally should rule and feed on the population. Lancre is an attractive new food source. Vampires also have mind control powers, control the weather, and can put their minds into magpies. They are, in short, enemies designed for Granny Weatherwax, the witch expert in headology. A shame that Granny is apparently off sulking. Nanny and Agnes may have to handle the vampires on their own, with the help of Magrat. One of the things that makes this book odd is that it seemed like Pratchett was setting up some character growth, giving Agnes a chance to shine, and giving Nanny Ogg a challenge that she didn't want. This sort of happens, but then nothing much comes of it. Most of the book is the vampires preening about how powerful they are and easily conquering Lancre, while everyone else flails ineffectively. Pratchett does pull together an ending with some nice set pieces, but that ending doesn't deliver on any of the changes or developments it felt like the story was setting up. We do get a lot of Granny, along with an amusingly earnest priest of Om (lots of references to Small Gods here, while firmly establishing it as long-ago history). Granny is one of my favorite Discworld characters, so I don't mind that, but we've seen Granny solve a lot of problems before. I wanted to see more of Agnes, who is the interesting new character and whose dynamic with her inner voice feels like it has a great deal of unrealized potential. There is a sharp and condensed version of comparative religion from Granny, which is probably the strongest part of the book and includes one of those Discworld quotes that has been widely repeated out of context:
"And sin, young man, is when you treat people as things. Including yourself. That's what sin is." "It's a lot more complicated than that " "No. It ain't. When people say things are a lot more complicated than that, they means they're getting worried that they won t like the truth. People as things, that's where it starts."
This loses a bit in context because this book is literally about treating people as things, and thus the observation feels more obvious when it arrives in this book than when you encounter it on its own, but it's still a great quote. Sadly, I found a lot of this book annoying. One of those annoyances is a pet peeve that others may or may not share: I have very little patience for dialogue in phonetically-spelled dialect, and there are two substantial cases of that here. One is a servant named Igor who speaks with an affected lisp represented by replacing every ess sound with th, resulting in lots of this:
"No, my Uncle Igor thtill workth for him. Been thtruck by lightning three hundred timeth and thtill putth in a full night'th work."
I like Igor as a character (he's essentially a refugee from The Addams Family, which adds a good counterpoint to the malicious and arrogant evil of the vampires), but my brain stumbles over words like "thtill" every time. It's not that I can't decipher it; it's that the deciphering breaks the flow of reading in a way that I found not at all fun. It bugged me enough that I started skipping his lines if I couldn't work them out right away. The other example is the Nac Mac Feegles, who are... well, in the book, they're Pictsies and a type of fairy, but they're Scottish Smurfs, right down to only having one female (at least in this book). They're entertainingly homicidal, but they all talk like this:
"Ach, hins tak yar scaggie, yer dank yowl callyake!"
I'm from the US and bad with accents and even worse with accents reproduced in weird spellings, and I'm afraid that I found 95% of everything said by Nac Mac Feegles completely incomprehensible to the point where I gave up even trying to read it. (I'm now rather worried about the Tiffany Aching books and am hoping Pratchett toned the dialect down a lot, because I'm not sure I can deal with more of this.) But even apart from the dialect, I thought something was off about the plot structure of this book. There's a lot of focus on characters who don't seem to contribute much to the plot resolution. I wanted more of the varied strengths of Lancre coming together, rather than the focus on Granny. And the vampires are absurdly powerful, unflappable, smarmy, and contemptuous of everyone, which makes for threatening villains but also means spending a lot of narrative time with a Discworld version of Jacob Rees-Mogg. I feel like there's enough of that in the news already. Also, while I will avoid saying too much about the plot, I get very suspicious when older forms of oppression are presented as good alternatives to modernizing, rationalist spins on exploitation. I see what Pratchett was trying to do, and there is an interesting point here about everyone having personal relationships and knowing their roles (a long-standing theme of the Lancre Discworld stories). But I think the reason why there is some nostalgia for older autocracy is that we only hear about it from stories, and the process of storytelling often creates emotional distance and a patina of adventure and happy outcomes. Maybe you can make an argument that classic British imperialism is superior to smug neoliberalism, but both of them are quite bad and I don't want either of them. On a similar note, Nanny Ogg's tyranny over her entire extended clan continues to be played for laughs, but it's rather unappealing and seems more abusive the more one thinks about it. I realize the witches are not intended to be wholly good or uncomplicated moral figures, but I want to like Nanny, and Pratchett seems to be writing her as likable, even though she has an astonishing lack of respect for all the people she's related to. One might even say that she treats them like things. There are some great bits in this book, and I suspect there are many people who liked it more than I did. I wouldn't be surprised if it was someone's favorite Discworld novel. But there were enough bits that didn't work for me that I thought it averaged out to a middle-of-the-road entry. Followed by The Fifth Elephant in publication order. This is the last regular witches novel, but some of the thematic thread is picked up by The Wee Free Men, the first Tiffany Aching novel. Rating: 7 out of 10

25 October 2022

Arturo Borrero Gonz lez: Netfilter Workshop 2022 summary

Netfilter logo This is my report from the Netfilter Workshop 2022. The event was held on 2022-10-20/2022-10-21 in Seville, and the venue was the offices of Zevenet. We started on Thursday with Pablo Neira (head of the project) giving a short welcome / opening speech. The previous iteration of this event was in virtual fashion in 2020, two years ago. In the year 2021 we were unable to meet either in person or online. This year, the number of participants was just eight people, and this allowed the setup to be a bit more informal. We had kind of an un-conference style meeting, in which whoever had something prepared just went ahead and opened a topic for debate. In the opening speech, Pablo did a quick recap on the legal problems the Netfilter project had a few years ago, a topic that was settled for good some months ago, in January 2022. There were no news in this front, which was definitely a good thing. Moving into the technical topics, the workshop proper, Pablo started to comment on the recent developments to instrument a way to perform inner matching for tunnel protocols. The current implementation supports VXLAN, IPIP, GRE and GENEVE. Using nftables you can match packet headers that are encapsulated inside these protocols. He mentioned the design and the goals, that was to have a kernel space setup that allows adding more protocols by just patching userspace. In that sense, more tunnel protocols will be supported soon, such as IP6IP, UDP, and ESP. Pablo requested our opinion on whether if nftables should generate the matching dependencies. For example, if a given tunnel is UDP-based, a dependency match should be there otherwise the rule won t work as expected. The agreement was to assist the user in the setup when possible and if not, print clear error messages. By the way, this inner thing is pure stateless packet filtering. Doing inner-conntracking is an open topic that will be worked on in the future. Pablo continued with the next topic: nftables automatic ruleset optimizations. The times of linear ruleset evaluation are over, but some people have a hard time understanding / creating rulesets that leverage maps, sets, and concatenations. This is where the ruleset optimizations kick in: it can transform a given ruleset to be more optimal by using such advanced data structures. This is purely about optimizing the ruleset, not about validating the usefulness of it, which could be another interesting project. There were a couple of problems mentioned, however. The ruleset optimizer can be slow, O(n!) in worst case. And the user needs to use nested syntax. More improvements to come in the future. Next was Stefano Brivio s turn (Red Hat engineer). He had been involved lately in a couple of migrations to nftables, in particular libvirt and KubeVirt. We were pointed to https://libvirt.org/firewall.html, and Stefano walked us through the 3 or 4 different virtual networks that libvirt can create. He evaluated some options to generate efficient rulesets in nftables to instrument such networks, and commented on a couple of ideas: having a null matcher in nftables set expression. Or perhaps having kind of subsets, something similar to a view in a SQL database. The room spent quite a bit of time debating how the nft_lookup API could be extended to support such new search operations. We also discussed if having intermediate facilities such as firewalld could provide the abstraction levels that could make developers more comfortable. Using firewalld also may have the advantage that coordination between different system components writing ruleset to nftables is handled by firewalld itself and developers are freed of the responsibility of doing it right. Next was Fernando F. Mancera (Red Hat engineer). He wanted to improve error reporting when deleting table/chain/rules with nftables. In general, there are some inconsistencies on how tables can be deleted (or flushed). And there seems to be no correct way to make a single table go away with all its content in a single command. The room agreed in that the commands destroy table and delete table should be defined consistently, with the following meanings: This topic diverted into another: how to reload/replace a ruleset but keep stateful information (such as counters). Next was Phil Sutter (Netfilter coreteam member and Red Hat engineer). He was interested in discussing options to make iptables-nft backward compatible. The use case he brought was simple: What happens if a container running iptables 1.8.7 creates a ruleset with features not supported by 1.8.6. A later container running 1.8.6 may fail to operate. Phil s first approach was to attach additional metadata into rules to assist older iptables-nft in decoding and printing the ruleset. But in general, there are no obvious or easy solutions to this problem. Some people are mixing different tooling version, and there is no way all cases can be predicted/covered. iptables-nft already refuses to work in some of the most basic failure scenarios. An other way to approach the issue could be to introduce some kind of support to print raw expressions in iptables-nft, like -m nft xyz. Which feels ugly, but may work. We also explored playing with the semantics of release version numbers. And another idea: store strings in the nft rule userdata area with the equivalent matching information for older iptables-nft. In fact, what Phil may have been looking for is not backwards but forward compatibility. Phil was undecided which path to follow, but perhaps the most common-sense approach is to fall back to a major release version bump (2.x.y) and declaring compatibility breakage with older iptables 1.x.y. That was pretty much it for the first day. We had dinner together and went to sleep for the next day. The room The second day was opened by Florian Westphal (Netfilter coreteam member and Red Hat engineer). Florian has been trying to improve nftables performance in kernels with RETPOLINE mitigations enabled. He commented that several workarounds have been collected over the years to avoid the performance penalty of such mitigations. The basic strategy is to avoid function indirect calls in the kernel. Florian also described how BPF programs work around this more effectively. And actually, Florian tried translating nf_hook_slow() to BPF. Some preliminary benchmarks results were showed, with about 2% performance improvement in MB/s and PPS. The flowtable infrastructure is specially benefited from this approach. The software flowtable infrastructure already offers a 5x performance improvement with regards the classic forwarding path, and the change being researched by Florian would be an addition on top of that. We then moved into discussing the meeting Florian had with Alexei in Zurich. My personal opinion was that Netfilter offers interesting user-facing interfaces and semantics that BPF does not. Whereas BPF may be more performant in certain scenarios. The idea of both things going hand in hand may feel natural for some people. Others also shared my view, but no particular agreement was reached in this topic. Florian will probably continue exploring options on that front. The next topic was opened by Fernando. He wanted to discuss Netfilter involvement in Google Summer of Code and Outreachy. Pablo had some personal stuff going on last year that prevented him from engaging in such projects. After all, GSoC is not fundamental or a priority for Netfilter. Also, Pablo mentioned the lack of support from others in the project for mentoring activities. There was no particular decision made here. Netfilter may be present again in such initiatives in the future, perhaps under the umbrella of other organizations. Again, Fernando proposed the next topic: nftables JSON support. Fernando shared his plan of going over all features and introduce programmatic tests from them. He also mentioned that the nftables wiki was incomplete and couldn t be used as a reference for missing tests. Phil suggested running the nftables python test-suite in JSON mode, which should complain about missing features. The py test suite should cover pretty much all statements and variations on how the nftables expression are invoked. Next, Phil commented on nftables xtables support. This is, supporting legacy xtables extensions in nftables. The most prominent problem was that some translations had some corner cases that resulted in a listed ruleset that couldn t be fed back into the kernel. Also, iptables-to-nftables translations can be sloppy, and the resulting rule won t work in some cases. In general, nft list ruleset nft -f may fail in rulesets created by iptables-nft and there is no trivial way to solve it. Phil also commented on potential iptables-tests.py speed-ups. Running the test suite may take very long time depending on the hardware. Phil will try to re-architect it, so it runs faster. Some alternatives had been explored, including collecting all rules into a single iptables-restore run, instead of hundreds of individual iptables calls. Next topic was about documentation on the nftables wiki. Phil is interested in having all nftables code-flows documented, and presented some improvements in that front. We are trying to organize all developer-oriented docs on a mediawiki portal, but the extension was not active yet. Since I worked at the Wikimedia Foundation, all the room stared at me, so at the end I kind of committed to exploring and enabling the mediawiki portal extension. Note to self: is this perhaps https://www.mediawiki.org/wiki/Portals ? Next presentation was by Pablo. He had a list of assorted topics for quick review and comment. Following this, a new topic was introduced by Stefano. He wanted to talk about nft_set_pipapo, documentation, what to do next, etc. He did a nice explanation of how the pipapo algorithm works for element inserts, lookups, and deletion. The source code is pretty well documented, by the way. He showed performance measurements of different data types being stored in the structure. After some lengthly debate on how to introduce changes without breaking usage for users, he declared some action items: writing more docs, addressing problems with non-atomic set reloads and a potential rework of nft_rbtree. After that, the next topic was kubernetes & netfilter , also by Stefano. Actually, this topic was very similar to what we already discussed regarding libvirt. Developers want to reduce packet matching effort, but also often don t leverage nftables most performant features, like sets, maps or concatenations. Some Red Hat developers are already working on replacing everything with native nftables & firewalld integrations. But some rules generators are very bad. Kubernetes (kube-proxy) is a known case. Developers simply won t learn how to code better ruleset generators. There was a good question floating around: What are people missing on first encounter with nftables? The Netfilter project doesn t have a training or marketing department or something like that. We cannot force-educate developers on how to use nftables in the right way. Perhaps we need to create a set of dedicated guidelines, or best practices, in the wiki for app developers that rely on nftables. Jozsef Kadlecsik (Netfilter coreteam) supported this idea, and suggested going beyond: such documents should be written exclusively from the nftables point of view: stop approaching the docs as a comparison to the old iptables semantics. Related to that last topic, next was Laura Garc a (Zevenet engineer, and venue host). She shared the same information as she presented in the Kubernetes network SIG in August 2020. She walked us through nftlb and kube-nftlb, a proof-of-concept replacement for kube-proxy based on nftlb that can outperform it. For whatever reason, kube-nftlb wasn t adopted by the upstream kubernetes community. She also covered latest changes to nftlb and some missing features, such as integration with nftables egress. nftlb is being extended to be a full proxy service and a more robust overall solution for service abstractions. In a nutshell, nftlb uses a templated ruleset and only adds elements to sets, which is exactly the right usage of the nftables framework. Some other projects should follow its example. The performance numbers are impressive, and from the early days it was clear that it was outperforming classical LVS-DSR by 10x. I used this opportunity to bring a topic that I wanted to discuss. I ve seen some SRE coworkers talking about katran as a replacement for traditional LVS setups. This software is a XDP/BPF based solution for load balancing. I was puzzled about what this software had to offer versus, for example, nftlb or any other nftables-based solutions. I commented on the highlighs of katran, and we discussed the nftables equivalents. nftlb is a simple daemon which does everything using a JSON-enabled REST API. It is already packaged into Debian, ready to use, whereas katran feels more like a collection of steps that you need to run in a certain order to get it working. All the hashing, caching, HA without state sharing, and backend weight selection features of katran are already present in nftlb. To work on a pure L3/ToR datacenter network setting, katran uses IPIP encapsulation. They can t just mangle the MAC address as in traditional DSR because the backend server is on a different L3 domain. It turns out nftables has a nft_tunnel expression that can do this encapsulation for complete feature parity. It is only available in the kernel, but it can be made available easily on the userspace utility too. Also, we discussed some limitations of katran, for example, inability to handle IP fragmentation, IP options, and potentially others not documented anywhere. This seems to be common with XDP/BPF programs, because handling all possible network scenarios would over-complicate the BPF programs, and at that point you are probably better off by using the normal Linux network stack and nftables. In summary, we agreed that nftlb can pretty much offer the same as katran, in a more flexible way. Group photo Finally, after many interesting debates over two days, the workshop ended. We all agreed on the need for extending it to 3 days next time, since 2 days feel too intense and too short for all the topics worth discussing. That s all on my side! I really enjoyed this Netfilter workshop round.

20 October 2022

Mike Gabriel: Ubuntu Touch development - Wanna sponsor ARM64 CPU power for CI build infrastructure?

What is Ubuntu Touch? (And what does sunweaver have to do with it?) With Ubuntu Touch, the UBports Foundation offers a truly unique mobile experience - a viable alternative to Android and iOS. The UBports community provides a free and open-source GNU/Linux-based mobile operating system. One that can be installed and used today. Currently, there is an intensive effort going on lifting Ubuntu Touch from its current Ubuntu 16.04 base up to an Ubuntu 20.04 base. (And very soon after that to an Ubuntu 22.04 base...). With the Ubuntu Touch 20.04 base the progress bar is already at (I'd say) 89%, but we recently got hit by a drawback. I am currently involved in the Ubuntu Touch core development team at UBports and on medium short notice our current ARM64 server sponsor has announced to decommission our ARM64 build server that currently powers all the ARM64 and armhf CI builds. Call for Hardware Sponsoring So, the UBports core development team is currently desperately looking for a sponsor (or a few sponsors) who can provide us with (datacenter-hosted) ARM-based CPU power. It is important, that also 32-bit ARM builds are possible with the hardware provided. For testing, I recently ordered a HoneyComb LX2 (by SolidRun) as a possible solution (multi-node in the end), but the board arrived in a non-usable state, it seems. So this also didn't work out as easy as expected. As the former provider/sponsor is about to pull the plug, this call for help is kind of urgent. Please get in touch if you can help us out or know people who can. Thanks!!!
Mike (sunweaver at debian.org, libera.chat, OFTC, Telegram, matrix.org, etc.)

19 October 2022

Shirish Agarwal: Pune Rains, Uncosted Budgets, Hearing Loss Covid, Fracking

Pune Rains Lemme start with a slightly funny picture that tells as much about Pune, my city as anything else does.
Pune- Leave your attitude behind, we have our own
This and similar tags, puns and whatnot you will find if you are entering Pune from the road highway. You can also find similar similar symbols and Puns all over the city and they are partly sarcasm and ironic and partly the truth. Puneities work from the attitude that they know everything rather than nothing, including yours truly  . What is the basis of that or why is there such kind of confidence I have no clue or idea, it is what it is. Approximately 24 hrs. ago, apparently we had a cloudburst. What I came to know later is that we got 100 mm of rain. Sharing from local news site. Much more interesting was a thread made on Reddit where many people half-seriously asked where they can buy a boat. One of the reasons being even if it s October, in fact, we passed middle of October and it s still raining. Even today in the evening, it rained for quite a while. As I had shared in a few blog posts before, June where rains should have started, it didn t, it actually started late July or even August, so something has shifted. The current leadership does not believe in Anthropogenic Climate Change or human activity induced climate change even though that is a reality. I could share many links and even using the term above should give links to various studies. Most of the people who are opposed to it are either misinformed or influenced from the fossil fuel industry. Again, could share many links, but will share just one atm. I have talked to quite a few people about it but nobody has ever been able to give a convincing answer as to why GM had to crush the cars. Let s even take the argument that it was the worst manufactured car in history and there have been quite a few, have the others been crushed? If not, then the reason shared or given by most people sounds hollow. And if you look into it, they had an opportunity that they let go, and now most of them are scrambling and yet most of the legacy auto manufacturers will be out of existence if they don t get back into the game in the next 2-3 years. There have been a bunch of announcements but we are yet to see. The Chinese though have moved far ahead, although one has to remark that they have been doing that for the last decade, so they have a 10-year head start, hardly surprising then. But I need to get back to the subject, another gentleman on Reddit remarked that if you start to use boat, and others start to use boat, then the Govt. will tax it. In fact, somebody had shared the below the other day
Different types of taxes collected by GOI
Many of the taxes that I have shared above are by the Modi Govt. who came on the platform, manifesto that once they come to power they will reduce taxes for the common man, they have reduced taxes but only for the Corporates. For the common man, the taxes have only gone up, both direct tax and indirect tax. Any reference to the Tory party who have also done similar things and have also shared that it is labor who had done large expenditures even though they have been 8 years in power, I am sure for most is purely coincidental. Incidentally, that is the same tack that was taken even by the Republican party. They all like to give tax benefits to the 1% while for the rest is austerity claiming some reason, even if it has been proven to be false.
Corporate Tax Rate, Revenue Loss to Govt.
The figures mentioned above are findings of parliamentary panel so nobody can accuse of anybody having a bias. Also, I probably had shared this but still feel the need to re-share it as people still believe that 2G scam happened even though there are plenty of arguments I can share to prove how it was all a fabricated lie.
Vinod Rai Mafinama in Uttarakhand High Court.
Part 2 of the same Mafinama.
How pathetic Mr. Rai s understanding of economics is can be gauged from the fact that he was made Chairman of IDFC and subsequently had to be thrown out. That whole lie was engineered to throw UPA out and it worked. There are and have been many such coincidences happening over the last 8 years, parallel stories happening in India and UK. This was just yesterday, about a year back Air India was given back to the Tatas, There was controversy about the supposed auctions as only Indigo was the only other party allowed to be at auction but not allowed to buy but more as a spectator as they already have 60% of the Indian civil aviation market. And there was lot of cheering from the Govt. side that finally Air India has been bought home to its true owners, the Tatas. The Tatas too started cheering and sharing how they will take down all the workers, worker unions and everything will be happy glory within a year. In fact, just couple of days back they shared new plans. Btw for the takeover of Air India, they had bought loans from the Banks and they are in the category of too big to fail. As I have shared couple of times before, RBI has not shared any inspection reports of nationalized or private banks after 2013/14. While by law, RBI is supposed to do inspection reports every 3 months and share them in the Public domain. And if you ask any of their supporter, for everything they will say UPA did x or y, which only goes to show morally bankrupt the present Govt. is. Coming back to the topic, before I forget, the idea of sharing their plans is so that they can again borrow money from the banks. But that is not the only story. Just one day back, Smita Prakash, one of the biggest cheerleaders of the present Govt. (she is the boss at Asia News International (ANI)) posted how Air India had treated her sister and other 21 passengers. Basically, they had bought business tickets but the whole cabin was dirty, they complained and they were forced to sit in economy class, not just her cousin sister but the other 21 odd passengers too. Of course Ms Smita became calm as her sister was given free air tickets on Vistara and other goodies. Of course, after that she didn t post anything about the other 21 odd passengers after that. And yes, I understand she is supposed to be a reporter but as can be seen from the twitter thread, there is or was no follow up. Incidentally, she is one of many who has calling others about Revdi culture (freebies to the masses.) but guess that only applies to other people not her or her sister. Again, if there are any coincidences of similar nature in the UK or when Trump was P.M. of the U.S. they are just coincidental .

The Uncosted budget India and the UK have many parallels, it s mind boggling. Before we get into the nitty-gritties, saw something that would be of some interest to the people here.
For those who might not be able to see above, apparently there is place in UK called Tufton Street where there are quite a few organizations that are shadowy and whose finances are not known as to how they are financed. Ms. Truss and quite a few of the people in the cabinet are from the same shadowy organizations. Mr. Kwasi Kwarteng, the just-departed chancellor is and was part of the same group. Now even for me it was a new term to learn and understand what is an uncosted budget is. To make it much more easier I share the example using a common person who goes to the bank for a loan

Now M/S X wants a loan of say Rs. 1000/- for whatever reason. He/she/they go to the bank and asks give me a loan of say INR 1000/- The banks asks them to produce a statement of accounts to show what their financial position is. They produce a somewhat half-filled statement of accounts In which all liabilities are shown, but incomes are not. The bank says you already have so much liabilities, how are you gonna pay those, accounts have to be matched otherwise you are not solvent. M/s X adamantly refuses to do any changes citing that they don t need to. At this point, M/s X credit rating goes down and nobody in the market will give them a loan. At the same time, the assets they had held, their value also depreciates because it became known that they can t act responsibly. So whose to say whether or not M/s X has those number of assets and priced them accurately. But the drama doesn t end there, M/s X says this is the responsibility of actually Mr. Z ( cue The Bank of England) as they are my accountant/lawyer etc. M/s Z says as any lawyer/accountant should. This is not under my remit. If the clients either gives incomplete information or false information or whatever then it is their responsibility not mine. And in fact, the Chancellor is supposed to be the one who is given the responsibility of making the budget. The Chancellor is very similar to our Finance Minister. Because the UK has constitutional monarchy, I am guessing the terms are slightly different, otherwise the functionality seems to be the same. For two weeks, there was lot of chaos, lot of pension funds lost quite a bit in the market and in the end Mr. Kwasi Kwarteng was ousted out of the job. Incredibly, the same media and newspapers who had praised Mr. Kwarteng just few weeks back as the best Tory budget, they couldn t wait to bury him. And while I have attempted to simplify what happened, the best explanation of what has happened can be found in an article from the guardian. Speculation is rife in the UK as to who s ruling atm as the new Chancellor has reversed almost all the policies that Ms. Truss had bought and she is now more or less a figurehead. Mr. Hunt, the new chancellor doesn t have anybody behind him. Apparently, the gentleman wanted to throw his hat the ring in the Tory leadership contest that was held about a month back and he couldn t get 20 MP s to support him. Another thing that is different between UK and India is that in UK by law the PM has to answer questions put up to him or her by the opposition leaders. That is the way accountability is measured there. This is known as PMQ s or Prime Minister Questions and Answers. One can just go to YouTube or any streaming service and give Liz Truss and PMQ s and if they are interested of a certain date, give a date and they can see how she answered the questions thrown at her. Unfortunately, all she could do in both times were non-answers. In fact, the Tories seem to be using some of Labor s policies after they had bad-mouthed the same policies. Politics of right-wing both in the UK and the US seems so out of touch with the people whom they are supposed to protect and administer. An article about cyclists which is sort of half-truth, half irony shows how screwed up the policies are of the RW (right-wing). Now they are questions about the pensions triple-lock. Sadly, it is the working class who would suffer the most, most of the rich have already moved their money abroad several years ago. The Financial Times, did share a video about how things have been unfolding

Seems Ms. Truss forgot to add Financial Times in the list of anti-growth coalition she is so fond of. Also, the Tory party seems to want to create more tax havens in the UK and calling them investment zones. Of course, most of the top tax havens are situated around the UK itself. I wouldn t go more into as that would probably require its own article, although most of that information is all in public domain. Fracking I don t really want to take much time as the blog post has become long. There have been many articles written why Fracking is bad and that is why even the Tories had put in their Manifesto that they won t allow Fracking but apparently, today they are trying to reopen Fracking. And again how bad it is and can be found out by the article in Guardian.

14 October 2022

Shirish Agarwal: Dowry, Racism, Railways

Dowry Few days back, had posted about the movie Raksha Bandhan and whatever I felt about it. Sadly, just couple of days back, somebody shared this link. Part of me was shocked and part of me was not. Couple of acquaintances of mine in the past had said the same thing for their daughters. And in such situations you are generally left speechless because you don t know what the right thing to do is. If he has shared it with you being an outsider, how many times he must have told the same to their wife and daughters? And from what little I have gathered in life, many people have justified it on similar lines. And while the protests were there, sadly the book was not removed. Now if nurses are reading such literature, how their thought process might be forming, you can tell :(. And these are the ones whom we call for when we are sick and tired :(. And I have not taken into account how the girls/women themselves might be feeling. There are similar things in another country but probably not the same, nor the same motivations though although feeling helplessness in both would be a common thing. But such statements are not alone. Another gentleman in slightly different context shared this as well
The above is a statement shared in a book recommended for CTET (Central Teacher s Eligibility Test that became mandatory to be taken as the RTE (Right To Education) Act came in.). The statement says People from cold places are white, beautiful, well-built, healthy and wise. And people from hot places are black, irritable and of violent nature. Now while I can agree with one part of the statement that people residing in colder regions are more fair than others but there are loads of other factors that determine fairness or skin color/skin pigmentation. After a bit of search came to know that this and similar articulation have been made in an idea/work called Environmental Determinism . Now if you look at that page, you would realize this was what colonialism is and was all about. The idea that the white man had god-given right to rule over others. Similarly, if you are fair, you can lord over others. Seems simplistic, but yet it has a powerful hold on many people in India. Forget the common man, this thinking is and was applicable to some of our better-known Freedom fighters. Pune s own Bal Gangadhar Tilak The Artic Home to the Vedas. It sort of talks about Aryans and how they invaded India and became settled here. I haven t read or have access to the book so have to rely on third-party sources. The reason I m sharing all this is that the right-wing has been doing this myth-making for sometime now and unless and until you put a light on it, it will continue to perpetuate  . For those who have read this blog, do know that India is and has been in casteism from ever. They even took the fair comment and applied it to all Brahmins. According to them, all Brahmins are fair and hence have god-given right to lord over others. What is called the Eton boy s network serves the same in this casteism. The only solution is those idea under limelight and investigate. To take the above, how does one prove that all fair people are wise and peaceful while all people black and brown are violent. If that is so, how does one count for Mahatma Gandhi, Martin Luther King Junior, Nelson Mandela, Michael Jackson the list is probably endless. And not to forget that when Mahatma Gandhiji did his nonviolent movements either in India or in South Africa, both black and brown people in millions took part. Similar examples of Martin Luther King Jr. I know and read of so many non-violent civl movements that took place in the U.S. For e.g. Rosa Parks and the Montgomery Bus Boycott. So just based on these examples, one can conclude that at least the part about the fair having exclusive rights to being fair and noble is not correct. Now as far as violence goes, while every race, every community has had done violence in the past or been a victim of the same. So no one is and can be blameless, although in light of the above statement, the question can argumentated as to who were the Vikings? Both popular imagination and serious history shares stories about Vikings. The Vikings were somewhat nomadic in nature even though they had permanent settlements but even then they went on raids, raped women, captured both men and women and sold them at slaves. So they are what pirates came to be, but not the kind Hollywood romanticizes about. Europe in itself has been a tale in conflict since time immemorial. It is only after the formation of EU that most of these countries stopped fighting each other From a historical point perspective, it is too new. So even the part of fair being non-violent dies in face of this evidence. I could go on but this is enough on that topic.

Railways and Industrial Action around the World. While I have shared about Railways so many times on this blog, it continues to fascinate me that how people don t understand the first things about Railways. For e.g. Railways is a natural monopoly. What that means is and you can look at all and any type of privatization around the world, you will see it is a monopoly. Unlike the road or Skies, Railways is and would always be limited by infrastructure and the ability to have new infrastructure. Unlike in road or Skies (even they have their limits) you cannot run train services on a whim. At any particular point in time, only a single train could and should occupy a stretch of Railway network. You could have more trains on one line, but then the likelihood of front or rear-end collisions becomes a real possibility. You also need all sorts of good and reliable communications, redundant infrastructure so if one thing fails then you have something in place. The reason being a single train can carry anywhere from 2000 to 5000 passengers or more. While this is true of Indian Railways, Railways around the world would probably have some sort of similar numbers.It is in this light that I share the below videos.
To be more precise, see the fuller video
Now to give context to the recording above, Mike Lynch is the general secretary at RMT. For those who came in late, both UK and the U.S. have been threatened by railway strikes. And the reason for the strikes or threat of strikes is similar. Now from the company perspective, all they care is to invest less and make the most profits that can be given to equity shareholders. At the same time, they have freezed the salaries of railway workers for the last 3 years. While the politicians who were asking the questions, apparently gave themselves raise twice this year. They are asking them to negotiate at 8% while inflation in the UK has been 12.3% and projected to go higher. And it is not only the money. Since the 1980s when UK privatized the Railways, they stopped investing in the infrastructure. And that meant that the UK Railway infrastructure over period of time started getting behind and is even behind say Indian Railways which used to provide most bang for the buck. And Indian Railways is far from ideal. Ironically, most of the operators on UK are nationalized Railways of France, Germany etc. but after the hard Brexit, they too are mulling to cut their operations short, they have too  There is also the EU Entry/Exit system that would come next year. Why am I sharing about what is happening in UK Rail, because the Indian Government wants to follow the same thing, and fooling the public into saying we would do it better. What inevitably will happen is that ticket prices go up, people no longer use the service, the number of services go down and eventually they are cancelled. This has happened both in Indian Railways as well as Airlines. In fact, GOI just recently announced a credit scheme just a few days back to help Airlines stay afloat. I was chatting with a friend who had come down to Pune from Chennai and the round-trip cost him INR 15k/- on that single trip alone. We reminisced how a few years ago, 8 years to be precise, we could buy an Air ticket for 2.5k/- just a few days before the trip and did it. I remember doing/experiencing at least a dozen odd trips via air in the years before 2014. My friend used to come to Pune, almost every weekend because he could afford it, now he can t do that. And these are people who are in the above 5-10% of the population. And this is not just in UK, but also in the United States. There is one big difference though, the U.S. is mainly a freight carrier while the UK Railway Operations are mostly passenger based. What was and is interesting that Scotland had to nationalize their services as they realized the Operators cannot or will not function when they were most needed. Most of the public even in the UK seem to want a nationalized rail service, at least their polls say so. So, it would definitely be interesting to see what happens in the UK next year. In the end, I know I promised to share about books, but the above incidents have just been too fascinating to not just share the news but also share what I think about them. Free markets function good where there is competition, for example what is and has been happening in China for EV s but not where you have natural monopolies. In all Railway privatization, you have to handover the area to one person, then they have no motivation. If you have multiple operators, then there would always be haggling as to who will run the train and at what time. In either scenario, it doesn t work and raises prices while not delivering anything better  I do take examples from UK because lot of things are India are still the legacy of the British. The whole civil department that was created in 1953 is/was a copy of the British civil department at that time and it is to this day. P.S. Just came to know that the UK Chancellor Kwasi Kwarteng was just sacked as UK Chancellor. I do commend Truss for facing the press even though she might be dumped a week later unlike our PM who hasn t faced a single press conference in the last 8 odd years.

https://www.youtube.com/watch?v=oTP6ogBqU7of The difference in Indian and UK politics seems to be that the English are now asking questions while here in India, most people are still sleeping without a care in the world. Another thing to note Minidebconf Palakkad is gonna happen 12-13th November 2022. I am probably not gonna go but would request everyone who wants to do something in free software to attend it. I am not sure whether I would be of any use like this and also when I get back, it would be an empty house. But for people young and old, who want to do anything with free/open source software it is a chance not to be missed. Registration of the same closes on 1st of November 2022. All the best, break a leg  Just read this, beautifully done.

Simon Josefsson: On language bindings & Relaunching Guile-GnuTLS

The Guile bindings for GnuTLS has been part of GnuTLS since spring 2007 when Ludovic Court s contributed it after some initial discussion. I have been looking into getting back to do GnuTLS coding, and during a recent GnuTLS meeting one topic was Guile bindings. It seemed like a fairly self-contained project to pick up on. It is interesting to re-read the old thread when this work was included: some of the concerns brought up there now have track record to be evaluated on. My opinion that the cost of introducing a new project per language binding today is smaller than the cost of maintaining language bindings as part of the core project. I believe the cost/benefit ratio has changed during the past 15 years: introducing a new project used to come with a significant cost but this is no longer the case, as tooling and processes for packaging have improved. I have had similar experience with Java, C# and Emacs Lisp bindings for GNU Libidn as well, where maintaining them centralized slow down the pace of updates. Andreas Metzler pointed to a similar conclusion reached by Russ Allbery. There are many ways to separate a project into two projects; just copying the files into a new git repository would have been the simplest and was my original plan. However Ludo mentioned git-filter-branch in an email, and the idea of keeping all git history for some of the relevant files seemed worth pursuing to me. I quickly found git-filter-repo which appears to be the recommend approach, and experimenting with it I found a way to filter out the GnuTLS repo into a small git repository that Guile-GnuTLS could be based on. The commands I used were the following, if you want to reproduce things.
$ git clone https://gitlab.com/gnutls/gnutls.git guile-gnutls
$ cd guile-gnutls/
$ git checkout f5dcbdb46df52458e3756193c2a23bf558a3ecfd
$ git-filter-repo --path guile/ --path m4/guile.m4 --path doc/gnutls-guile.texi --path doc/extract-guile-c-doc.scm --path doc/cha-copying.texi --path doc/fdl-1.3.texi
I debated with myself back and forth whether to include some files that would be named the same in the new repository but would share little to no similar lines, for example configure.ac, Makefile.am not to mention README and NEWS. Initially I thought it would be nice to preserve the history for all lines that went into the new project, but this is a subjective judgement call. What brought me over to a more minimal approach was that the contributor history and attribution would be quite strange for the new repository: Should Guile-GnuTLS attribute the work of the thousands of commits to configure.ac which had nothing to do with Guile? Should the people who wrote that be mentioned as contributor of Guile-GnuTLS? I think not. The next step was to get a reasonable GitLab CI/CD pipeline up, to make sure the project builds on some free GNU/Linux distributions like Trisquel and PureOS as well as the usual non-free distributions like Debian and Fedora to have coverage of dpkg and rpm based distributions. I included builds on Alpine and ArchLinux as well, because they tend to trigger other portability issues. I wish there were GNU Guix docker images available for easy testing on that platform as well. The GitLab CI/CD rules for a project like this are fairly simple. To get things out of the door, I tagged the result as v3.7.9 and published a GitLab release page for Guile-GnuTLS that includes OpenPGP-signed source tarballs manually uploaded built on my laptop. The URLs for these tarballs are not very pleasant to work with, and discovering new releases automatically appears unreliable, but I don t know of a better approach. To finish this project, I have proposed a GnuTLS merge request to remove all Guile-related parts from the GnuTLS core. Doing some GnuTLS-related work again felt nice, it was quite some time ago so thank you for giving me this opportunity. Thoughts or comments? Happy hacking!

9 October 2022

Jonathan Dowland: Focus writing with (despite) LaTeX

LaTeX the age-old typesetting system makes me angry. Not because it's bad. To clarify, not because there's something better. But because there should be. When writing a document using LaTeX, if you are prone to procrastination it can be very difficult to focus on the task at hand, because there are so many yaks to shave. Here's a few points of advice. In a nutshell, I think it's wise to move much document reviewing work back into the editor rather than the rendered document, at least in the early stages of a section. And to do that, you need the document to be as legible as possible in the editor. The important stuff is the text you write, not the TeX macros you've sprinkled around to format it. A few tips I benefit from in terms of source formatting: Of course, you need to review the rendered document too! I like to bounce that to a tablet with a pen/stylus/pencil and review it in a different environment to where I write. I then end up with a long list of scrawled notes, and a third distinct activity, back at the writing desk, is to systematically go through them and apply some GTD-style thinking to them: can I fix it in a few seconds? Do it straight away. Delegate it? Unlikely Defer it? transfer the review note into another system of record (such as LaTeX \\todo ). And finally

Sergio Talens-Oliag: Shared networking for Virtual Machines and Containers

This entry explains how I have configured a linux bridge, dnsmasq and iptables to be able to run and communicate different virtualization systems and containers on laptops running Debian GNU/Linux. I ve used different variations of this setup for a long time with VirtualBox and KVM for the Virtual Machines and Linux-VServer, OpenVZ, LXC and lately Docker or Podman for the Containers.

Required packagesI m running Debian Sid with systemd and network-manager to configure the WiFi and Ethernet interfaces, but for the bridge I use bridge-utils with ifupdown (as I said this setup is old, I guess ifupdow2 and ifupdown-ng will work too). To start and stop the DNS and DHCP services and add NAT rules when the bridge is brought up or down I execute a script that uses:
  • ip from iproute2 to get the network information,
  • dnsmasq to provide the DNS and DHCP services (currently only the dnsmasq-base package is needed and it is recommended by network-manager, so it is probably installed),
  • iptables to configure NAT (for now docker kind of forces me to keep using iptables, but at some point I d like to move to nftables).
To make sure you have everything installed you can run the following command:
sudo apt install bridge-utils dnsmasq-base ifupdown iproute2 iptables

Bridge configurationThe bridge configuration for ifupdow is available on the file /etc/network/interfaces.d/vmbr0:
# Virtual servers NAT Bridge
auto vmbr0
iface vmbr0 inet static
    address         10.0.4.1
    network         10.0.4.0
    netmask         255.255.255.0
    broadcast       10.0.4.255
    bridge_ports    none
    bridge_maxwait  0
    up              /usr/local/sbin/vmbridge $ IFACE  start nat
    pre-down        /usr/local/sbin/vmbridge $ IFACE  stop nat
Warning: To use a separate file with ifupdown make sure that /etc/network/interfaces contains the line:
source /etc/network/interfaces.d/*
or add its contents to /etc/network/interfaces directly, if you prefer.
This configuration creates a bridge with the address 10.0.4.1 and assumes that the machines connected to it will use the 10.0.4.0/24 network; you can change the network address if you want, as long as you use a private range and it does not collide with networks used in your Virtual Machines all should be OK. The vmbridge script is used to start the dnsmasq server and setup the NAT rules when the interface is brought up and remove the firewall rules and stop the dnsmasq server when it is brought down.

The vmbridge scriptThe vmbridge script launches an instance of dnsmasq that binds to the bridge interface (vmbr0 in our case) that is used as DNS and DHCP server. The DNS server reads the /etc/hosts file to publish local DNS names and forwards all the other requests to the the dnsmasq server launched by NetworkManager that is listening on the loopback interface. As this server already does catching we disable it for our server, with the added advantage that, if we change networks, new requests go to the new resolvers because the DNS server handled by NetworkManager gets restarted and flushes its cache (this is useful if we connect to a new network that has internal DNS servers that are configured to do split DNS for internal services; if we use this model all requests get the internal address as soon as the DNS server is queried again). The DHCP server is configured to provide IPs to unknown hosts for a sub range of the addresses on the bridge network and use fixed IPs if the /etc/ethers file has a MAC with a matching hostname on the /etc/hosts file. To make things work with old DHCP clients the script also adds checksums to the DHCP packets using iptables (when the interface is not linked to a physical device the kernel does not add checksums, but we can fix it adding a rule on the mangle table). If we want external connectivity we can pass the nat argument and then the script creates a MASQUERADE rule for the bridge network and enables IP forwarding. The script source code is the following:
/usr/local/sbin/vmbridge
#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
LOCAL_DOMAIN="vmnet"
MIN_IP_LEASE="192"
MAX_IP_LEASE="223"
# ---------
# FUNCTIONS
# ---------
get_net()  
  NET="$(
    ip a ls "$ BRIDGE " 2>/dev/null   sed -ne 's/^.*inet \(.*\) brd.*$/\1/p'
  )"
  [ "$NET" ]   return 1
 
checksum_fix_start()  
  iptables -t mangle -A POSTROUTING -o "$ BRIDGE " -p udp --dport 68 \
    -j CHECKSUM --checksum-fill 2>/dev/null   true
 
checksum_fix_stop()  
  iptables -t mangle -D POSTROUTING -o "$ BRIDGE " -p udp --dport 68 \
    -j CHECKSUM --checksum-fill 2>/dev/null   true
 
nat_start()  
  [ "$NAT" = "yes" ]   return 0
  # Configure NAT
  iptables -t nat -A POSTROUTING -s "$ NET " ! -d "$ NET " -j MASQUERADE
  # Enable forwarding (just in case)
  echo 1 >/proc/sys/net/ipv4/ip_forward
 
nat_stop()  
  [ "$NAT" = "yes" ]   return 0
  iptables -t nat -D POSTROUTING -s "$ NET " ! -d "$ NET " \
    -j MASQUERADE 2>/dev/null   true
 
do_start()  
  # Bridge address
  _addr="$ NET%%/* "
  # DNS leases (between .MIN_IP_LEASE and .MAX_IP_LEASE)
  _dhcp_range="$ _addr%.* .$ MIN_IP_LEASE ,$ _addr%.* .$ MAX_IP_LEASE "
  # Bridge mtu
  _mtu="$(
    ip link show dev "$ BRIDGE "  
      sed -n -e '/mtu/   s/^.*mtu \([0-9]\+\).*$/\1/p  '
  )"
  # Compute extra dnsmasq options
  dnsmasq_extra_opts=""
  # Disable gateway when not using NAT
  if [ "$NAT" != "yes" ]; then
    dnsmasq_extra_opts="$dnsmasq_extra_opts --dhcp-option=3"
  fi
  # Adjust MTU size if needed
  if [ -n "$_mtu" ] && [ "$_mtu" -ne "1500" ]; then
    dnsmasq_extra_opts="$dnsmasq_extra_opts --dhcp-option=26,$_mtu"
  fi
  # shellcheck disable=SC2086
  dnsmasq --bind-interfaces \
    --cache-size="0" \
    --conf-file="/dev/null" \
    --dhcp-authoritative \
    --dhcp-leasefile="/var/lib/misc/dnsmasq.$ BRIDGE .leases" \
    --dhcp-no-override \
    --dhcp-range "$ _dhcp_range " \
    --domain="$ LOCAL_DOMAIN " \
    --except-interface="lo" \
    --expand-hosts \
    --interface="$ BRIDGE " \
    --listen-address "$ _addr " \
    --no-resolv \
    --pid-file="$ PIDF " \
    --read-ethers \
    --server="127.0.0.1" \
    $dnsmasq_extra_opts
  checksum_fix_start
  nat_start
 
do_stop()  
  nat_stop
  checksum_fix_stop
  if [ -f "$ PIDF " ]; then
    kill "$(cat "$ PIDF ")"   true
    rm -f "$ PIDF "
  fi
 
do_status()  
  if [ -f "$ PIDF " ] && kill -HUP "$(cat "$ PIDF ")"; then
    echo "dnsmasq RUNNING"
  else
    echo "dnsmasq NOT running"
  fi
 
do_reload()  
  [ -f "$ PIDF " ] && kill -HUP "$(cat "$ PIDF ")"
 
usage()  
  echo "Uso: $0 BRIDGE (start stop [nat]) status reload"
  exit 1
 
# ----
# MAIN
# ----
[ "$#" -ge "2" ]   usage
BRIDGE="$1"
OPTION="$2"
shift 2
NAT="no"
for arg in "$@"; do
  case "$arg" in
  nat) NAT="yes" ;;
  *) echo "Unknown arg '$arg'" && exit 1 ;;
  esac
done
PIDF="/var/run/vmbridge-$ BRIDGE -dnsmasq.pid"
case "$OPTION" in
start) get_net && do_start ;;
stop) get_net && do_stop ;;
status) do_status ;;
reload) get_net && do_reload ;;
*) echo "Unknown command '$OPTION'" && exit 1 ;;
esac
# vim: ts=2:sw=2:et:ai:sts=2

NetworkManager ConfigurationThe default /etc/NetworkManager/NetworkManager.conf file has the following contents:
[main]
plugins=ifupdown,keyfile
[ifupdown]
managed=false
Which means that it will leave interfaces managed by ifupdown alone and, by default, will send the connection DNS configuration to systemd-resolved if it is installed. As we want to use dnsmasq for DNS resolution, but we don t want NetworkManager to modify our /etc/resolv.conf we are going to add the following file (/etc/NetworkManager/conf.d/dnsmasq.conf) to our system:
/etc/NetworkManager/conf.d/dnsmasq.conf
[main]
dns=dnsmasq
rc-manager=unmanaged
and restart the NetworkManager service:
$ sudo systemctl restart NetworkManager.service
From now on the NetworkManager will start a dnsmasq service that queries the servers provided by the DHCP servers we connect to on 127.0.0.1:53 but will not touch our /etc/resolv.conf file.

Configuring systemd-resolvedIf we start using our own name server but our system has systemd-resolved installed we will no longer need or use the DNS stub; programs using it will use our dnsmasq server directly now, but we keep running systemd-resolved for the host programs that use its native api or access it through /etc/nsswitch.conf (when libnss-resolve is installed). To disable the stub we add a /etc/systemd/resolved.conf.d/disable-stub.conf file to our machine with the following content:
# Disable the DNS Stub Listener, we use our own dnsmasq
[Resolve]
DNSStubListener=no
and restart the systemd-resolved to make sure that the stub is stopped:
$ sudo systemctl restart systemd-resolved.service

Adjusting /etc/resolv.confFirst we remove the existing /etc/resolv.conf file (it does not matter if it is a link or a regular file) and then create a new one that contains at least the following line (we can add a search line if is useful for us):
nameserver 10.0.4.1
From now on we will be using the dnsmasq server launched when we bring up the vmbr0 for multiple systems:
  • as our main DNS server from the host (if we use the standard /etc/nsswitch.conf and libnss-resolve is installed it is queried first, but the systemd-resolved uses it as forwarder by default if needed),
  • as the DNS server of the Virtual Machines or containers that use DHCP for network configuration and attach their virtual interfaces to our bridge,
  • as the DNS server of docker containers that get the DNS information from /etc/resolv.conf (if we have entries that use loopback addresses the containers that don t use the host network tend to fail, as those addresses inside the running containers are not linked to the loopback device of the host).

TestingAfter all the configuration files and scripts are in place we just need to bring up the bridge interface and check that everything works:
$ # Bring interface up
$ sudo ifup vmbr0
$ # Check that it is available
$ ip a ls dev vmbr0
4: vmbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
          group default qlen 1000
    link/ether 0a:b8:ef:b8:07:6c brd ff:ff:ff:ff:ff:ff
    inet 10.0.4.1/24 brd 10.0.4.255 scope global vmbr0
       valid_lft forever preferred_lft forever
$ # View the listening ports used by our dnsmasq servers
$ sudo ss -tulpan   grep dnsmasq
udp UNCONN 0 0  127.0.0.1:53     0.0.0.0:* users:(("dnsmasq",pid=1733930,fd=4))
udp UNCONN 0 0  10.0.4.1:53      0.0.0.0:* users:(("dnsmasq",pid=1705267,fd=6))
udp UNCONN 0 0  0.0.0.0%vmbr0:67 0.0.0.0:* users:(("dnsmasq",pid=1705267,fd=4))
tcp LISTEN 0 32 10.0.4.1:53      0.0.0.0:* users:(("dnsmasq",pid=1705267,fd=7))
tcp LISTEN 0 32 127.0.0.1:53     0.0.0.0:* users:(("dnsmasq",pid=1733930,fd=5))
$ # Verify that the DNS server works on the vmbr0 address
$ host www.debian.org 10.0.4.1
Name: 10.0.4.1
Address: 10.0.4.1#53
Aliases:
www.debian.org has address 130.89.148.77
www.debian.org has IPv6 address 2001:67c:2564:a119::77

Managing running systemsIf we want to update DNS entries and/or MAC addresses we can edit the /etc/hosts and /etc/ethers files and reload the dnsmasq configuration using the vmbridge script:
$ sudo /usr/local/sbin/vmbridge vmbr0 reload
That call sends a signal to the running dnsmasq server and it reloads the files; after that we can refresh the DHCP addresses from the client machines or start using the new DNS names immediately.

4 October 2022

Jonathan Dowland: rewrite rule representation

I've begun writing up my phd and, not for the first time, I'm pondering issues of how best to represent things. Specifically, rewrite rules. Here's one way of representing an example rewrite rule:
streamFilter g . streamFilter f = streamFilter (g . f)
This is a fairly succinct representation. It's sort-of Haskell, but not quite. It's an equation. The left-hand side is a pattern: it's intended to describe not one expression but a family of expressions that match. The lower case individual letters g and f are free variables: labelled placeholders within the pattern that can be referred to on the right hand side. I haven't stipulated what defines a free variable and what is a more concrete part of the pattern. It's kind-of Haskell, and I've used the well-known operator . to represent the two stream operators (streamFilters) being connected together. (In practice, when we get to the system where rules are actually applied, the connecting operator is not going to be . at all, so this is also an approximation). One thing I don't like about . here, despite its commonness, is having to read right-to-left. I adopted the habit of using the lesser-known >>> in a lot of my work (which is defined as (>>>) = flip (.)), which reads left-to-right. And then I have the reverse problem: people aren't familiar with >>>, and, just like ., it's a stand-in anyway. Towards the beginning of my PhD, I spent some time inventing rewrite rules to operate on pairs of operators taken from a defined, known set. I began representing the rules much as in the example above. Later on, I wanted to encode them as real Haskell, in order to check them more thoroughly. The above rule, I first encoded like this
filterFilterPre     = streamFilter g . streamFilter f
filterFilterPost    = streamFilter (g . f)
prop_filterFilter s = filterFilterPre s == filterFilterPost s
This is real code: the operators were already implemented in StrIoT, and the final expression defined a property for QuickCheck. However, it's still not quite a rewrite rule. The left-hand side, which should be a pattern, is really a concrete expression. The names f and g are masquerading as free variables but are really concretely defined in a preamble I wrote to support running QuickCheck against these things: usually simple stuff like g = odd, etc. Eventually, I had to figure out how to really implement rewrite rules in StrIoT. There were a few approaches I could take. One would be to express the rules in some abstract form like the first example (but with properly defined semantics) and write a parser for them: I really wanted to avoid doing that. As a happy accident, the solution I landed on was enabled by the semantics of algebraic-graphs, a Graph library we adopted to support representing a stream-processing topology. I wrote more about that in data-types for representing stream-processing programs. I was able to implement rewrite rules as ordinary Haskell functions. The left-hand side of the rewrite rule maps to the left-hand side (pattern) part of a function definition. The function body implements the right-hand side. The system that applies the rules attempts to apply each rewrite rule to every sub-graph of a stream-processing program. The rewrite functions therefore need to signal whether or not they're applicable at runtime. For that reason, the return type is wrapped in Maybe, and we provide a catch-all pattern for every rule which simply returns Nothing. The right-hand side implementation can be pretty thorny. On the left-hand side, the stream operator connector we've finally ended up with is Connect from algebraic-graphs. Here's filter fuse, taken from the full ruleset:
filterFuse :: RewriteRule
filterFuse (Connect (Vertex a@(StreamVertex i (Filter sel1) (p:_) ty _ s1))
                    (Vertex b@(StreamVertex _ (Filter sel2) (q:_) _ _ s2))) =
    let c = a   operator    = Filter (sel1 * sel2)
              , parameters  = [\[  (\p q x -> p x && q x) $(p) $(q)  ]]
              , serviceTime = sumTimes s1 sel1 s2
               
    in Just (removeEdge c c . mergeVertices ( elem  [a,b]) c)
filterFuse _ = Nothing
That's perhaps the simplest rule in the set. (See e.g. hoistOp for one of the worst!) The question that remains to me, is, which representation, or representations, to use in the thesis? I'm currently planning to skip the abstract example I started with and start with the concrete Haskell encoding using QuickCheck. I'm not sure if it seems weird to have two completely separate implementations of the rules, but the simpler QuickCheck-checked rules are much closer to the "core essence" of the rules than the final implementation in StrIoT. And the derivation of the rules comes earlier in the timeline than the design work that led to the final StrIoT implementation. The middle-option is still compromised, however, by having concrete expressions pretending to be patterns. So I'm not sure.

Abhijith PA: Laptop refreshment

(Sorry if you have read this already, due to a tag mistake, my draft copy got published) laptop I recently bought a refurbished thinkpad x260. If you have read my post of my <a href= <!DOCTYPE html> Laptop refreshment