597 private links
Passwordstore is a great password manager, and I rely on it also in my Ansible playbooks, where it works by causing the gpg-agent to prompt me for the passphrase of my gpg key.
This prompt is a GUI prompt, which is very suitable when sitting at the computer in question. But a small annoyance is that it does not work at all when working on a remote computer via ssh (the prompt shows up on the remote computer's desktop, and the Ansible playbook in the terminal just freezes until it eventually fails).
It would be so much nicer if those ssh terminal sessions would instead get the gpg-agent prompt in the terminal. So far I have not found a method that achieves this without also sacrificing the GUI desktop prompt for non-remote work.
Desktop and laptop running Ubuntu 22.04 with i3wm desktop.
The relevant parts of my config can be seen in https://codeberg.org/ansible/dotfiles.
I considered the following related Q:s&A:s but did not achieve the desired outcome.
- https://unix.stackexchange.com/questions/554153/what-is-the-proper-configuration-for-gpg-ssh-and-gpg-agent-to-use-gpg-auth-sub
- https://stackoverflow.com/questions/17769831/how-to-make-gpg-prompt-for-passphrase-on-cli
- https://superuser.com/questions/1189602/how-to-configure-gpg2-to-ask-for-passphrase-on-the-console-instead-of-in-a-popup
- https://unix.stackexchange.com/questions/217737/pinentry-fails-with-gpg-agent-and-ssh
Some more tests
In the SSH session (no effect, unfortunately):
gpg-connect-agent updatestartuptty /byeLearned that the gpg-agent is running in --supervised mode, and its ENV variables include DISPLAY=:0:
solarchemist@desktop:~
$ sudo cat /proc/2652288/environ
HOME=/home/solarchemist LANG=en_US.UTF-8 LC_TIME=sv_SE.UTF-8 LOGNAME=solarchemist
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/snap/bin
SHELL=/bin/bash SYSTEMD_EXEC_PID=2652288 USER=solarchemist
XDG_DATA_DIRS=/home/solarchemist/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share/:/usr/share/:/var/lib/snapd/desktop
XDG_RUNTIME_DIR=/run/user/1000 QT_ACCESSIBILITY=1
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus DISPLAY=:0 XAUTHORITY=/home/solarchemist/.Xauthority
MANAGERPID=1532 LISTEN_PID=2652288 LISTEN_FDS=4
LISTEN_FDNAMES=browser:extra:std:ssh INVOCATION_ID=<stuff> JOURNAL_STREAM=<stuff>(the PID of the gpg-agent process is easily identified with ps aux | grep [g]pg).
Manual work-around
Manual work-around is to set pinentry-program /usr/bin/pinentry-tty in ~/.gnupg/gpg-agent.conf and reload the agent gpg-connect-agent reloadagent /bye.
To revert to the default (GUI) pinentry behaviour, just remove the line and reload the agent again.
How could we go about to draw a straight line (vertical or horizontal) on top of any other window on our Linux desktop? I'm using i3 window manager with picom compositor at present, so I'm primarily interested in solutions that works for that.
I should get back to this question in the future and implement a nicer solution than pango-view
pango-view
Produces a vertical line (actually, more of a vertical box of limited width).
Very easy to make it, just issue the command in a terminal. pango-view was already installed.
$ pango-view --height=99999 --margin=1 --background=red -t ''- https://forum.puppylinux.com/viewtopic.php?p=76743 relevant, very good and recent
- https://askubuntu.com/questions/328543/are-there-any-tools-for-drawing-on-the-desktop-drawing-over-apps
gromit-mpxis a good over-app painter, but does not provide perfectly straight lines- https://www.linuxfordevices.com/tutorials/linux/tools-to-draw-on-linux-screen
Will add more as I learn about them. I only care about FOSS projects.
LXD
See my Ansible role that installs and configures LXD and provisions LXC containers.
Docker
I have some experience with Docker containers. Prefer LXC if I have the choice.
I have written an Ansible playbook to setup containers with docker-compose as part of a as-yet not-public project for InvenioRDM.
Podman
No hands-on experience yet.
Singularity
Hm, interesting. Could it be better than Docker for sharing something like a thesis with "all batteries included", I wonder?
Singularity can convert Docker containers to Singularity, or can run containers directly from Docker Hub
https://blogs.oregonstate.edu/learningbydoing/2022/01/04/docker-and-singularity-containers-which-one-is-better/
Learn the skills required to sysadmin a remote Linux server from the commandline.
Course restarts every first Monday of the month
I wanted to create an ASCII art "bismillah" for use in the terminal.
Found this beautiful calligraphy by Nuria Garcia Masip. After cropping it, rotating it slightly and making the background monochromatic, I tried the ascii-image-converter by Zoraiz Hassan, and it worked great with the --braille flag:
This converter tool was really easy to install (just run the binary), and the output was automatically resized to fit the terminal window size, which was a convenient feature.
I discovered some other ASCII art CLI tools (never tested them though):
This is a neat way to quickly generate a QR-code, for example to transfer text from computer to phone (thanks to Solène Rapenne for the original idea and implementation). On the phone, you'll of course need to use a QR-reader app, such as Binary Eye.
xclip -o -selection clipboard | qrencode -o - -t PNG | feh -g 600x600 -Z -Using this command, whatever is in your clipboard will be encoded to QR and displayed on your monitor. Note that xclip can pull stuff from different clipboards, and in my case the contents were not picked up with -selection default but -selection clipboard did the trick.
Linux (well, really the window managers, so X11 and then, i3, Wayland, etc…) have multiple clipboards. The default ones are the Primary selection one, and the Secondary one. The names are historical accidents, but the “primary” one always has a copy of the last text you selected from anywhere, which can be pasted anywhere by clicking the middle mouse button. You just select some text and that’s it - you don’t have to do anything else and you can then middle-click paste this anywhere. The “secondary” clipboard is the “normal” Cut, Copy, Paste, Ctrl+c, Ctrl+v one.
https://duncanlock.net/blog/2022/04/06/using-windows-after-15-years-on-linux/
- i3wm, tiling window manager for X11.
- sway, drop-in replacement for i3wm on Wayland.
- enlightenment, window manager, compositor and minimal desktop. Not tiling. Supports X11, experimental Wayland support.
There are many more window managers. Add more as I (re)discover them.
Guides and how-tos
- Introduction to Ansible playbooks
- Playbooks vs roles, and explain the difference between task, role, play and playbook
- How to install and configure Ansible on Ubuntu 18.04 - DigitalOcean
- Linux hardening using idempotency with Ansible
Ansible playbooks and roles
- I haven't published all roles that I've written, but all the roles that I do publish are collected at codeberg.org/ansible
- Ansible module (Python code) to install R packages, by yutannihilation
- Ansible role to install TeXLive
- https://ansible.jeffgeerling.com/
- https://robertdebock.nl/ansible.html
This could perhaps be a much more stable alternative to my reverse SSH tunnels for keeping connections with various servers, especially desktops inside FM-NET and other machines inside other LANs.
The main downside is that Tailscale is not FOSS. So perhaps we should look for other solutions built on WireGuard, or perhaps learn to configure WireGuard directly.
The command and its typical output (highlights not shown due to technical limitations in Markdown):
me@host:~/ansible/playbooks
$ find . -type f -name "playbook.log" -exec sh -c 'tac {} | grep -m 1 -A1 "^Playbook last committed by"' \; | grep --color -E "^|git/ansible/[A-Za-z]+?/[A-Za-z-]+?.yml|(19|20)[0-9][0-9]-(0[1-9]|1[0-2])-(0[1-9]|[12][0-9]|3[01]) [0-9]{2}:[0-9]{2}:[0-9]{2},[0-9]{3}"
Playbook last committed by me@host on Fri Apr 17 22:02:15 2020 +0200 (afd13a3b3b3f43d3f84bb16b1c91a6b5bec2cfe1)
2020-04-19 00:40:30,925 p=32526 u=me n=ansible | task path: /home/me/ansible/playbooks/luxor/playbook-host.yml:99
Playbook last committed by me@host on Wed Jan 29 14:34:38 2020 +0100 (5157cd051e276abfe99e93c37a8ad0c79dd4d3dc)
2020-03-29 01:39:34,874 p=14553 u=me n=ansible | task path: /home/me/ansible/playbooks/damietta/playbook-heliopolis.yml:31
Playbook last committed by me@host on Tue Feb 18 17:30:19 2020 +0100 (ae6c02965f4471d8089c5e4d2a427cb0cbfbc6b8)
2020-02-23 19:58:30,188 p=1050 u=me n=ansible | task path: /home/me/ansible/playbooks/abydos/playbook-webserver.yml:35
Playbook last committed by me@host on Sun Jan 5 09:44:27 2020 +0100 (26392ab778deaf86430f36bc7aed942ae04a938c)
2020-01-08 13:26:35,647 p=me u=27195 | changed: [hunan.domain.se -> localhost] => {"changed": true, "cmd": "git log --pretty=\"Playbook last committed by %cn on %cd (%H)\" -1 >> playbook.log", "delta": "0:00:00.003510", "end": "2020-01-08 13:26:35.628135", "rc": 0, "start": "2020-01-08 13:26:35.624625", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}
Playbook last committed by me@host on Thu Mar 26 14:57:00 2020 +0100 (2c9aa2030192c2942c5dfb0bcf5976f46fefd774)
2020-04-01 15:44:19,057 p=10821 u=me n=ansible | task path: /home/me/ansible/playbooks/alexandria/playbook.yml:137The first find command lists all playbook.log files below the current directory (recursing into child directories). tac is the opposite of cat and lists each file backwards (from last line to first). We use grep to look for a string ("Playbook last committed") that my Ansible playbooks always insert into the log-file at the end of a run. Note the use of the -A1 flag that gets the matched line and one line after (but because we used tac, we actually get the line before, which is what we want). The final grep uses extended regular expressions (-E) to color highlight several parts of the output (while displaying all of the output, that's what the initial caret does - it effectively matches all lines).
Pretty neat, if I may say so myself.
Some of the refs I consulted to figure out this one-liner:
https://serverfault.com/questions/197123/getting-the-last-match-in-a-file-using-grep
https://unix.stackexchange.com/questions/112159/grep-from-the-end-of-a-file-to-the-beginning
https://stackoverflow.com/questions/307015/how-do-i-include-a-pipe-in-my-linux-find-exec-command
https://superuser.com/questions/914856/grep-display-all-output-but-highlight-search-matches
https://unix.stackexchange.com/questions/366/convince-grep-to-output-all-lines-not-just-those-with-matches
https://unix.stackexchange.com/questions/37313/how-do-i-grep-for-multiple-patterns-with-pattern-having-a-pipe-character
https://en.wikipedia.org/wiki/Regular_expression#POSIX_extended