On Debian Trixie, Dovecot gets upgraded to version 2.4 which makes substantial changes to the configuration syntax and also to the log output. Unfortunately, the new log format for unsuccessful authentication might not match the rules defined in /etc/fail2ban/filter.d/dovecot.conf. This bug has been documented in the Debian bug tracking system as #1107903 but remains unaddressed […]
Articles in Category "Administration"
fail2ban not matching Dovecot 2.4 log output on Debian Trixie
19. Januar 2026 in Administration, GNU/Linux, Technology.
Migrating Dovecot CE to 2.4
19. Januar 2026 in Administration, GNU/Linux, Technology.
I use the Dovecot server as provided by the Debian GNU/Linux distribution. Dist-upgrading to Debian 13 “Trixie” forced an upgrade from Dovecot CE version 2.3 to 2.4, imposing significant changes to the configuration syntax. Fortunately, no features or functionality (that i am using) went away. Instead of the “before-and-after” way of explaining how to port […]
An Introduction to Programmable Completion in Bash
25. Juli 2025 in Administration, GNU/Linux, Programming.
I am using the terminal a lot on Linux. For my project “pulseaudio-tcp” (see here for more information) i wanted to have more comfortable command line completion in Bourne Again Shell (“Bash”). After having typed in the command name pulseaudio-tcp, when pressing the Tabulator key, i would like to see a list of all possible […]
Release of pulseaudio-tcp
28. Mai 2025 in Administration, GNU/Linux, Multimedia, Programming.
pulseaudio-tcp now has its first official release. The initial release features the following changes: GUI support with zenity for setup and other user interaction Debian packaging
A simple GUI for basic Package Management with Apt
2. Dezember 2024 in Administration, GNU/Linux, Programming, Technology.
The tool presented here, “Simple Apt Update” (simple-apt-update) is nothing more than a front-end to the non-interactive execution of apt-get update|full-upgrade and apt list –upgradeable. It can look like this:
Utility to search for XDG Desktop Files
3. November 2024 in Administration, GNU/Linux, Programming, Technology.
In my previous article Print XDG Desktop Definition for Application i described a way to search the various “applications” sub-directories of the known XDG data directories for .desktop-files that match certain search criteria. The short shell script from that article is now available as a commandline utility, including the usual bells and whistles such as […]
Getting Alerted on Expiring GPG Keys
3. August 2024 in Administration, GNU/Linux, Programming.
GnuPG is a powerful cryptographic tool that enjoys widespread support by F/LOSS mail user agents. However, due to a lack of conventional public key management it is plagued by key-related issues. One such issue is the expiry of GnuPG keys, which often goes unnoticed by affected messaging partners until such time when it actually disturbs […]
Redirect PulseAudio/PipeWire over TCP/IP network
8. Oktober 2023 in Administration, GNU/Linux, Multimedia, Technology.
If you have two Linux hosts, host1 and host2, both running PulseAudio (or Pipewire with PulseAudio backwards compatibility) and you want host2 to use the speakers on host1, then you can use a PulseAudio TCP server on host1 and a “tunnel sink” on host2 to do that.