The following configuration generates a systemd unit that doesn't
start.
```nix
{
services.syncthing = {
enable = true;
user = "my-user";
};
}
```
It fails with
```
systemd[1]: Started Syncthing service.
systemd[6745]: syncthing.service: Failed to determine group credentials: No such process
systemd[6745]: syncthing.service: Failed at step GROUP spawning /nix/store/n1ydz3i08nqp1ajc50ycy1zribmphqc9-syncthing-1.1.4-bin/bin/syncthing: No such process
systemd[1]: syncthing.service: Main process exited, code=exited, status=216/GROUP
systemd[1]: syncthing.service: Failed with result 'exit-code'.
```
This is due to the fact that `syncthing` group (default) is not
created if the user is overridden.
Add a separate check for setting up the default group, so that
user/group are created independently.
We were already creating a group for the user under which to run syncthing but
we were defaulting to running as `nogroup`.
Additionally, use `install` instead of multiple calls to mkdir/cp/chown.
Currently only for the user services as NixOS handles the named system
instances slightly differently.
syncthing and syncthing-inotify are done the same way.
There are 4 parts to this:
1) Copy in the upstream unit files
2) Make the nixos module use the definition from upstream
3) Enable restarting of all instances (system and user) on resume
4) Allow the traffic in the firewall on default ports if wanted
fixes#18973
- add missing types in module definitions
- add missing 'defaultText' in module definitions
- wrap example with 'literalExample' where necessary in module definitions
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
