Debian on Andrew Quinn's TILs

Where is the DevOps for Yocto?

Sat, 27 Sep 2025 00:00:00 +0000

The cozy world of DevOps has spoiled me with tools like Ansible, Terraform, and Packer. In the situations where I have a Linux machine already booted up, and sometimes already connected to the Internet, I can make things really easy on myself by slinging these tools in my usual way for repeatable, reproducible machines that may or may not come with the attendant headaches of immutable infrastructure (sorry, Nix, I’m not in love with you, I’m in love with the idea of you).

Consider the cronslave

Fri, 30 May 2025 00:00:00 +0000

As a nerdy, working-class kid who grew up in the 1990s, knowing what time it actually was was a luxury I rarely had access to before I was 12 or so and my parents finally got an Internet connection with its attendant link to the Network Time Protocol. If you had told me I could have not just a watch but an entire machine that

Never lost the time,
Did what I wanted, how I wanted it, and
Could be programmed to do what I want, how I want it on a schedule,

I would have had to substantially revise my Christmas wishlist.

LLMs make Perl great again

Sat, 24 May 2025 00:00:00 +0000

Perl 5 went through a long nadir of unpopularity due in large part to its deserved “Write Once, Read Never” reputation. So I was surprised to find out not only is it installed by default on Debian, it’s installed nearly everywhere by default. It’s even the non-shell scripting language of choice on OpenBSD!

Perhaps the only thing more impressive than Perl’s utter ubiquity is its longevity. The latest major version of Perl was first released in 1994. It came into existence on this planet less than a year after I did. It’s even arguably more portable than the median shell script - different Unices might use Bash, Zsh, Ksh, or even something newfangled like Fish, but for the most part a Perl 5 program is a Perl 5 program is a Perl 5 program.

Common-sense security for SSH on a new Debian server

Tue, 24 Sep 2024 00:00:00 +0000

Last night I went to DigitalOcean and spun up a tiny new, $4/month droplet – on my own dime! It sounds crazy, but I’ve never actually wanted to pay for hosting myself before. But I have a fun little web app cooking up, one that might eventually pay that $4/month back with interests, and I decided, why not, it’s time to finally put some of my own skin in the game with this whole sysadmin thing.

What scripting languages come out of the box on Debian 12?

Sun, 23 Jun 2024 00:00:00 +0000

Poking around in a fresh VM in Vagrant, I see

bash
dash, a POSIX compliant shell linked under sh
python3, 3.11.2 at the time of writing
awk, specifically mawk
sed, if you count that (I do)
perl, specifically Perl 5

There may be others I missed.

Why I’m curious: Knowing that a language is installed by default on the most popular Linux distribution can simplify certain concerns considerably, which are of special interest to people who don’t work on Internet-connected boxes. Knowing that Python/Perl is already on there means that, provided your script only relies on the standard library, you should be able to just scp it over in a pinch and have it “just work”.

One problem with user-scoped `systemd` timers

Sun, 26 Nov 2023 00:00:00 +0000

I’ve discovered one big downside of [putting systemd times into ~/.config/systemd/user/][1]: They stop running when you log out.

Two ways around this problem:

Bite the bullet, and install the timers into /etc/systemd/. This means giving up chezmoi version control, making the overall system more snowflake-y. I’m not crazy about it.
Remote in with tmux, instead of ever logging out, just use C-b d to detach from the session.

I’m going with #2. The lead developer of ktty is known not to like tmux, so there’s probably a way to detach long-running SSH sections inside of kitty itself – but I haven’t found it yet. Have you?

That damned Debian 10 one-liner I always need to let me `sudo`

Mon, 20 Nov 2023 00:00:00 +0000

1
2

# ⚠️: Reboots your VM.
su -c "$(whereis adduser | awk '{print $2}') $(whoami) sudo && $(whereis reboot | awk '{print $2}')"

In all its glory! For Debian 10 and up, because Debian 10 is where the sysv to systemd conversion became totalizing.

Let’s break down quickly why each part of this is needed:

Since we are trying to add ourselves to the sudo group right now, we obviously can’t use sudo. Enter su -c to switch to root, run a command, and then switch back out.

whereis adduser instead of simply adduser because adduser is no longer in the $PATH by default anymore.

Tempted to try which adduser? No dice – which only gets you things in the $PATH as well:

1
2
3

andrew@debian-10:~$ which adduser    # zip, zilch, nada.
andrew@debian-10:~$ whereis adduser
adduser: /usr/sbin/adduser /etc/adduser.conf /usr/share/adduser /usr/share/man/man8/adduser.8.gz

awk to rip out /usr/sbin/adduser, which - thankfully - at least is still executable.
$(whoami) because your name might not be andrew!
whereis reboot because I don’t want to have to manually remember to logout and login again.