FLOSS Project Planets

Posted on January 2, 2024 Tags: debian, free software, life

Just a little while ago (10 years) I proposed the addition of a state folder to the XDG basedir specification and expanded the article XDGBaseDirectorySpecification in the Debian wiki. Recently I learned, that version 0.8 (from May 2021) of the spec finally includes a state folder.

Granted, I wasn’t the first to have this idea (2009), nor the one who actually made it happen.

Now, please go ahead and use it! Thank you.

Posted on June 9, 2022 Tags: debian, free software

I’ve been using rsync for years and still did not know its full powers. I just wanted a quick and dirty simple backup but realised that rsnapshot is not in Debian anymore.

However you can do much of rsnapshot with rsync alone nowadays.

The --link-dest option (manpage) solves the part of creating hardlinks to a previous backup (found here). So my backup program becomes this shell script in ~/backups/backup.sh:

#!/bin/sh SERVER="${1}" BACKUP="${HOME}/backups/${SERVER}" SNAPSHOTS="${BACKUP}/snapshots" FOLDER=$(date --utc +%F_%H-%M-%S) DEST="${SNAPSHOTS}/${FOLDER}" LAST=$(ls -d1 ${SNAPSHOTS}/????-??-??_??-??-??|tail -n 1) rsync \ --rsh="ssh -i ${BACKUP}/sshkey -o ControlPath=none -o ForwardAgent=no" \ -rlpt \ --delete --link-dest="${LAST}" \ ${SERVER}::backup "${DEST}"

The script connects to rsync in daemon mode as outlined in section “USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION” in the rsync manpage. This allows to reference a “module” as the source that is defined on the server side as follows:

[backup] path = / read only = true exclude from = /srv/rsyncbackup/excludelist uid = root gid = root

The important bit is the read only setting that protects the server against somebody with access to the ssh key to overwrit files on the server via rsync and thus gaining full root access.

Finally the command prefix in ~/.ssh/authorized_keys runs rsync as daemon with sudo and the specified config file:

command="sudo rsync --config=/srv/rsyncbackup/config --server --daemon ."

The sudo setup is left as an exercise for the reader as mine is rather opinionated.

Unfortunately I have not managed to configure systemd timers in the way I wanted and therefor opened an issue: “Allow retry of timer triggered oneshot services with failed conditions or asserts”. Any help there is welcome!

Posted on May 1, 2022 Tags: debian, free software, life

Back at $COMPANY we had an internal meme-site. I had some reputation in my team for creating good memes. When I watched Episode 3 of Season 2 from Yes Premier Minister yesterday, I really missed a place to post memes.

This is the full scene. Please watch it or even the full episode before scrolling down to the GIFs. I had a good laugh for some time.

With Debian, I could just download the episode from somewhere on the net with youtube-dl and easily create two GIFs using ffmpeg, with and without subtitle:

ffmpeg -ss 0:5:59.600 -to 0:6:11.150 -i Downloads/Yes.Prime.Minister.S02E03-1254485068289.mp4 tmp/tragic.gif ffmpeg -ss 0:5:59.600 -to 0:6:11.150 -i Downloads/Yes.Prime.Minister.S02E03-1254485068289.mp4 \ -vf "subtitles=tmp/sub.srt:force_style='Fontsize=60'" tmp/tragic_with_subtitle.gif

And this sub.srt file:

1 00:00:10,000 --> 00:00:12,000 Tragic.

I believe, one needs to install the libavfilter-extra variant to burn the subtitle in the GIF.

Some

space

to

hide

the

GIFs.

The Premier Minister just learned, that his predecessor, who was about to publish embarassing memories, died of a sudden heart attack:

I can’t actually think of a meme with this GIF, that the internal thought police community moderation would not immediately take down.

For a moment I thought that it would be fun to have a Meme-Site for Debian members. But it is probably not the right time for this.

Maybe somebody likes the above GIFs though and wants to use them somewhere.

Posted on March 12, 2022 Tags: debian

The Language Server Protocol (LSP) standardizes communication between editors and so called language servers for different programming languages. This reduces the old problem that every editor had to implement many different plugins for all different programming languages. With LSP an editor just needs to talk LSP and can immediately provide typicall IDE features.

I already packaged the Emacs packages lsp-mode and lsp-haskell for Debian bullseye. Now lsp-java is waiting in the NEW queue.

I’m always worried about downloading and executing binaries from random places of the internet. It should be a matter of hygiene to only run binaries from official Debian repositories. Unfortunately this is not feasible when programming and many people don’t see a problem with running multiple curl-sh pipes to set up their programming environment.

I prefer to do such stuff only in virtual machines. With Emacs and LSP I can finally have a lightweight textmode programming environment even for Java.

Unfortunately the lsp-java mode does not yet work over tramp. Once this is solved, I could run emacs on my host and only isolate the code and language server inside the VM.

The next step would be to also keep the code on the host and mount it with Virtio FS in the VM. But so far the necessary daemon is not yet in Debian (RFP: #1007152).

In Detail I uploaded these packages:

• emacs-request ITP #1007113
• bui.el ITP #1007153
• emacs-posframe ITP #1007158
• lsp-treemacs ITP #1007119
• dap-mode ITP #1007160
• emacs-lsp-java ITP #1007162

Posted on February 18, 2014 Tags: debian, free software

The XDG Basedirectory specification proposes default homedir folders for the categories DATA (~/.local/share), CONFIG (~/.config) and CACHE (~/.cache). One category however is missing: STATE. This category has been requested several times but nothing happened.

Examples for state data are:

• history files of shells, repls, anything that uses libreadline
• logfiles
• state of application windows on exit
• recently opened files
• last time application was run
• emacs: bookmarks, ido last directories, backups, auto-save files, auto-save-list

The missing STATE category is especially annoying if you’re managing your dotfiles with a VCS (e.g. via VCSH) and you care to keep your homedir tidy.

If you’re as annoyed as me about the missing STATE category, please voice your opinion on the XDG mailing list.

Of course it’s a very long way until applications really use such a STATE directory. But without a common standard it will never happen.

Cleaning up KDE's metadata – the little things matter too

Lots of my KDE contributions revolve around plugin code and their metadata, meaning I have a good overview of where and how metadata is used. In this post, I will highlight some recent changes and show you how to utilize them in your Plasma Applets and KRunner plugins!

Applet and Containment metadata

Applets (or Widgets) are one of Plasma's main selling points regarding customizability. Next to user-visible information like the name, description and categories, there is a need for some technical metadata properties. This includes X-Plasma-API-Minimum-Version for the compatible versions, the ID and the package structure, which should always be “Plasma/Applet”.

For integrating with the system tray, applets had to specify the X-Plasma-NotificationArea and X-Plasma-NotificationAreaCategory properties. The first one says that it may be shown in the system tray and the second one says in which category it belongs. But since we don't want any applets without categories in there, the first value is redundant and may be omitted! Also, it was treated like a boolean value, but only "true" or "false" were expected. I stumbled upon this when correcting the types in metadata files.
This was noticed due to preparations for improving the JSON linting we have in KDE. I will resume working on it and might also blog about it :).

What most applets in KDE specify is X-KDE-MainScript, which determines the entrypoint of the applet. This is usually “ui/main.qml”, but in some cases the value differs. When working with applets, it is confusing to first have to look at the metadata in order to find the correct file. This key was removed in Plasma6 and the file is always ui/main.qml. Since this was the default value for the property, you may even omit it for Plasma5.
The same filename convention is also enforced for QML config modules (KCMs).

What all applets needed to specify was X-Plasma-API. This is typically set to "declarativeappletscript", but we de facto never used its value, but enforced it being present. This was historically needed because in Plasma4, applets could be written in other scripting languages. From Plasma6 onward, you may omit this key.

In the Plasma repositories, this allowed me to clean up over 200 lines of JSON data.

metadata.desktop files of Plasma5 addons

Just in case you were wondering: We have migrated from metadata.desktop files to only metadata.json files in Plasma6. This makes providing metadata more consistent and efficient. In case your projects still use the old format, you can run desktoptojson -i pathto/metadata.desktop and remove the file afterward.
See https://develop.kde.org/docs/plasma/widget/properties/#kpackagestructure for more detailed information. You can even do the conversion when targeting Plasma5 users!

Default object path for KRunner DBus plugins

Another nice addition is that “/runner” will now be the default object path. This means you can omit this one key. Check out the template to get started: https://invent.kde.org/frameworks/krunner/-/tree/master/templates/runner6python. DBus-Runners that worked without deprecations in Plasma5 will continue to do so in Plasma6! For C++ plugins, I will make a porting guide like blog post soonish, because I have started porting my own plugins to work with Plasma6.

Finally, I want to wish you all a happy and productive new year!