NixOS Containers
There's not much to read here. Look at NixOS Manual, the upstream documentation on containers meanwhile.
Troubleshooting
I have changed the host's channel and some services are acting weird
Acting weird could be any of those, non exhaustive symptoms:
- Lost data in PostgreSQL database
Solution
If you did not have a system.stateVersion option set inside your declarative container configuration, it will use the default one for the channel. Your data might be safe, if you did nothing meanwhile. Add the missing system.stateVersion to your container, rebuild, and possibly stop/start the container.