1. 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.

Previous article about Fossil cheatsheet

2. 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.

3. 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.

[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.

4. 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:

[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.

5. 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.