Comment by drdexebtjl

You would add something like:

    services.restic.backups.my_repo.paths = [ config.services.freshrss.dataDir ];

The point is that you write the general part of the restic config (like the schedule and the S3 endpoint) once, in one place (i.e restic.nix). Then each service-specific part of the restic config, like the line above, lives next to other configs for the freshrss service (i.e. freshrss.nix, not restic.nix). Then a build step generates scripts and systemd units for restic from the merged config. This makes it very easy to remove any service and all traces of it, even when it has “cross-cutting” configs.