This adds a simple configuration for sending snapshots to a remote
system using zfs-replicate that ties into the autoSnapshot settings
already present in services.zfs.autoSnapshot.
If lib.optional is given a false value it will return an empty list.
Thusly the set-environment script can have
```
export GTK_USE_PORTAL=
```
This can rub certain bugs the wrong way #65679
so lets make sure this isn't set in the environment
at all.
Prior to this change GTK_USE_PORTAL was unconditionally
set to "1". For this to not break things you have to have some
sort of portal implementation in extraPortals.
Setting GTK_USE_PORTAL in this manner is actually only useful
when using portals for applications outside flatpak. For example
people using non-flatpak Firefox who want native filechoosers.
It's also WIP for electron applications to support this.
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.
Upstream switched to a different type of ipset table, whereas we
create ipset in post-start which overrides upstream, and renders
sshguard ineffective.
Remove ipset creation from post-start, and let it get automatically
by upstream script (sshg-fw-ipset) as part of startup
Introduces a trim timer similar to the fstrim service.
According to zpool(8) for consumer hardware periodic manual TRIM
is preferred over automatic TRIM that ZFS implements.
The period of one week is based on recommendations of fstrim.
