Title: Qubes OS dom0 files workflow using fossil
Author: Solène
Date: 04 June 2023
Tags: qubesos fossil
Description: In this article, you will learn how to manage your Qubes
OS dom0 files in a revision control system, and how to synchronize it.
# Introduction
Since I'm using Qubes OS, I always faced an issue; I need a proper
tracking of the configuration files for my systemthis can be done using
Salt as I explained in a previous blog post. But what I really want is
a version control system allowing me to synchronize changes to a remote
repository (it's absurd to backup dom0 for every change I make to a
salt file). So far, git is too complicated to achieve that.
I gave a try with fossil, a tool I like (I wrote about this one too ;)
), and it was surprisingly easy to setup remote access leveraging
Qubes'qvm-run.
In this blog post, you will learn how to setup a remote fossil
repository, and how to use it from your dom0.
HTML Previous article about Fossil cheatsheet
# Repository creation
On the remote system where you want to store the fossil repository
(it's a single file), run `fossil init my-repo.fossil`.
The only requirement for this remote system is to be reachable over SSH
by an AppVM in your Qubes OS.
# dom0 clone
Now, we will clone this remote repository in our dom0, I'm personnally
fine with storing such files in `/root/` directory.
In the following example, the file `my-repo.fossil` was created on the
machine `10.42.42.200` with the path
`/home/solene/devel/my-repo.fossil`. I'm using the AppVM `qubes-devel`
to connect to the remote host using SSH.
```command
[root@dom0 ~#] fossil clone --ssh-command "qvm-run --pass-io --no-gui -u user qubes-devel 'ssh'" ssh://10.42.42.200://home/solene/devel/my-repo.fossil /root/my-repo.fossil
```
This command clone a remote fossil repository by piping the SSH command
through qubes-devel AppVM, allowing fossil to reach the remote host.
Cool fact with fossil's clone command, it keeps the proxy settings, so
no further changes are required.
With a Split SSH setup, I'm asked everytime fossil is synchronizing; by
default fossil has "autosync" mode enabled, for every commit done the
database is synced with the remote repository.
# Open the repository (reminder about fossil usage)
As I said, fossil works with repository files. Now you cloned the
repository in `/root/my-repo.fossil`, you could for instance open it in
`/srv/` to manage all your custom changes to the dom0 salt.
This can be achieved with the following command:
```shell
[root@dom0 ~#] cd /srv/
[root@dom0 ~#] fossil open --force /root/my-repo.fossil
```
The `--force` flag is needed because we need to open the repository in
a non-empty directory.
# Conclusion
Finally, I figured a proper way to manage my dom0 files, and my whole
host. I'm very happy of this easy and reliable setup, especially since
I'm already a fossil user. I don't really enjoy git, so demonstrating
alternatives working fine always feel great.
If you want to use Git, I have a hunch that something could be done
using `git bundle`, but this requires some investigation.