System Log #3: Replacing the git user with user accounts

Published on 2022-05-08

While I use sourcehut for my public programming presence online, I also have a git user on my VPS where I keep private copies of various git repositories. For a while, I used gitweb to show certain repositories at git.smlavine.com, but it was clunky to configure, so I turned that off once I established myself on sourcehut. As of writing, that subdomain redirects to my sr.ht profile.

This works well and good, but it has its flaws. For one thing, all repositories have the same access level: the git user. That means I can't give certain SSH keys access to only some repositories. Unix is meant to be a multi-user environment, so I am going to be deleting git and replacing it with a personal smlavine user. In the future, I might recreate the git user, for public read-only access. But not right now.

I have find . -maxdepth 4 -type d -name '\*.git' | wc -l => 30 repositories I need to replace. Another change I'm going to make while I'm here is to keep things flat: at the moment, I have some repositories in directories to match a sourcehut project they're in, like so:

...
./smlss/scripts.git
./smlss/dmenu.git
./smlss/st.git
./smlss/dots.git
./smlss/svkbd.git
./smlss/dwm.git
...
./aurpackages/jo-aur.git
./aurpackages/aurpackages.git
./aurpackages/catgirl-aur.git

But no more.

First things first, let's make this user:

git@blue:~$ su
Password:
root@blue:/home/git# cd
root@blue:~# useradd -ms /bin/bash smlavine
root@blue:~# passwd smlavine  # Generated with pass(1)
New password:
Retype new password:
passwd: password updated successfully

Good start, let's see what we got:

root@blue:~# ls -A /home/smlavine
.bash_logout  .bashrc  .profile

Looks about right. I'm going to quickly rm /home/smlavine/.bash_logout /home/smlavine/.bashrc, so that I can instead use the system default /etc/bash.bashrc I've already installed. Now let's get login going:

root@blue:~# cd /home/smlavine
root@blue:/home/smlavine# l
.profile
root@blue:/home/smlavine# mkdir .ssh
root@blue:/home/smlavine# curl -L https://meta.sr.ht/~smlavine.keys > .ssh/authorized_keys
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   205  100   205    0     0    186      0  0:00:01  0:00:01 --:--:--   186
root@blue:/home/smlavine# chown -R smlavine:smlavine .
root@blue:/home/smlavine# ll
total 8.0K
-rw-r--r-- 1 smlavine smlavine  807 Apr 18  2019 .profile
drwxr-xr-x 2 smlavine smlavine 4.0K May  9 01:08 .ssh/

Now I create new bare git repos for each I am moving from git:

$ ssh git@smlavine.com find . -maxdepth 4 -type d -name '\*.git' | xargs -I'{}' basename '{}' .git | sed 's:^:git/:' > repos.txt
Enter passphrase for key '/home/sebastian/.ssh/id_ed25519':
$ ssh smlavine@smlavine.com xargs -L1 git init --bare < repos.txt
Enter passphrase for key '/home/sebastian/.ssh/id_ed25519':
Initialized empty Git repository in /home/smlavine/git/mazesolver/
...
...
Initialized empty Git repository in /home/smlavine/git/aurpackages/
Initialized empty Git repository in /home/smlavine/git/catgirl-aur/

I thought about somehow automating finding the directories containing the code and changing the remote, but that would take more time than just doing it manually. I did, however, use some awk magic to make updating the origin go a lot faster in most of the repos:

master$ function orig() { git remote -v | awk -F: '/origin/ { sub(/\.git.*$/, ""); print $2 }' | xargs -I'{}' git remote set-url origin smlavine@smlavine.com:git/'{}'; git push origin; }
master$ orig
Enter passphrase for key '/home/sebastian/.ssh/id_ed25519':
Enumerating objects: 53, done.
Counting objects: 100% (53/53), done.
Delta compression using up to 4 threads
Compressing objects: 100% (53/53), done.
Writing objects: 100% (53/53), 16.07 KiB | 4.02 MiB/s, done.
Total 53 (delta 19), reused 0 (delta 0), pack-reused 0
To smlavine.com:git/colat
 * [new branch]      master -> master

This worked for most of the repos, except those where the git repo was nested in a directory. But it was easy to edit those manually. In this process, I also deleted two remotes that I decided I didn't need anymore, bringing down to 28.

I also added the SSH key from my phone in this process.

After this, I removed the git user. But, as git is also hooked up to dovecot, I had to do the trick that I also did for nickreg:

$ ssh smlavine@smlavine.com
Enter passphrase for key '/home/sebastian/.ssh/id_ed25519':
Last login: Tue May 10 18:26:40 2022 from 72.65.17.226
smlavine@blue:~$ su
Password:
root@blue:/home/smlavine# service dovecot stop; \
> deluser --remove-home git; \
> service dovecot start
Looking for files to backup/remove ...
Removing files ...
Removing user `git' ...
Done.
root@blue:/home/smlavine# exit
exit
smlavine@blue:~$ exit
logout
Connection to smlavine.com closed.

I'm happy that I've gotten this done. It will allow me to be more flexible in how I use my server for Git in the future.