How I install Mullvad on Silverblue based distros and add repos
One of the things I struggled with initailly when using immutables was installing programs like VPNS that need to interact with the immutable parts of the distro but don't have a flatpak option. I figured I'd just make a post to help anyone with this specific issue regarding mullvad or if it helps people install other software they need.
I don't know anything about immutable distros, but any good VPN provide Wireguard or OpenVPN config that you can just import into your network settings/manager. Mullvad does.
Very cool! Mullvad also updated their Linux install guides to reference the repos immediately, but they use dnf for whatever reason, making it unnecessarily complicated (issue report).
Your commands where good and secure, but this is a quicker way
You dont need sudo for rpm-ostree and systemctl, they work natively with polkit. In general you can replace sudo with pkexec in your shell config and have easier and more granular permission controls. But dont remove sudo, that will currently break at least some things like shutdown.
Doesnt work. Networkmanager has no native concept of a "airtight VPN mode".
The mullvad daemon does stuff like
control DNS
block internet when not connected
prevent early boot connections
Those require it to be privileged. For sure it would be nice to have all these features integrated into networkmanager, and vpn apps just placing their wireguard configs and DNS settings in there.
But for now the Mullvad App is way better than what we have. You can also keep a very insecure DNS conf (no DNSSEC, no DOT, no custom servers) as a fallback for public wifi bs, and when the Mullvad app is running the system uses a secure DNS.