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. (HTM) 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.