nixos/restic: add option to inhibit going to sleep

nixos/doc/manual/release-notes/rl-2411.section.md

@@ -211,6 +211,8 @@
   - Nemo is now built with gtk-layer-shell support, note that for now it will be expected to see nemo-desktop
     listed as a regular entry in Cinnamon Wayland session's window list applet.
 
+- `restic` module now has an option for inhibiting system sleep while backups are running, defaulting to off (not inhibiting sleep), available as [`services.restic.backups.<name>.inhibitsSleep`](#opt-services.restic.backups._name_.inhibitsSleep).
+
 - Support for *runner registration tokens* has been [deprecated](https://gitlab.com/gitlab-org/gitlab/-/issues/380872)
   in `gitlab-runner` 15.6 and is expected to be removed in `gitlab-runner` 18.0. Configuration of existing runners
   should be changed to using *runner authentication tokens* by configuring

nixos/modules/services/backup/restic.nix

@@ -83,6 +83,15 @@ in
           '';
         };
 
+        inhibitsSleep = mkOption {
+          default = false;
+          type = types.bool;
+          example = true;
+          description = ''
+            Prevents the system from sleeping while backing up.
+          '';
+        };
+
         repository = mkOption {
           type = with types; nullOr str;
           default = null;
@@ -299,7 +308,14 @@ in
         (name: backup:
           let
             extraOptions = concatMapStrings (arg: " -o ${arg}") backup.extraOptions;
-            resticCmd = "${backup.package}/bin/restic${extraOptions}";
+            inhibitCmd = concatStringsSep " " [
+              "${pkgs.systemd}/bin/systemd-inhibit"
+              "--mode='block'"
+              "--who='restic'"
+              "--what='sleep'"
+              "--why=${escapeShellArg "Scheduled backup ${name}"} "
+            ];
+            resticCmd = "${optionalString backup.inhibitsSleep inhibitCmd}${backup.package}/bin/restic${extraOptions}";
             excludeFlags = optional (backup.exclude != []) "--exclude-file=${pkgs.writeText "exclude-patterns" (concatStringsSep "\n" backup.exclude)}";
             filesFromTmpFile = "/run/restic-backups-${name}/includes";
             doBackup = (backup.dynamicFilesFrom != null) || (backup.paths != null && backup.paths != []);

nixos/tests/restic.nix

@@ -4,6 +4,7 @@ import ./make-test-python.nix (
   let
     remoteRepository = "/root/restic-backup";
     remoteFromFileRepository = "/root/restic-backup-from-file";
+    remoteInhibitTestRepository = "/root/restic-backup-inhibit-test";
     remoteNoInitRepository = "/root/restic-backup-no-init";
     rcloneRepository = "rclone:local:/root/restic-rclone-backup";
 
@@ -66,6 +67,12 @@ import ./make-test-python.nix (
                 find /opt -mindepth 1 -maxdepth 1 ! -name a_dir # all files in /opt except for a_dir
               '';
             };
+            inhibit-test = {
+              inherit passwordFile paths exclude pruneOpts;
+              repository = remoteInhibitTestRepository;
+              initialize = true;
+              inhibitsSleep = true;
+            };
             remote-noinit-backup = {
               inherit passwordFile exclude pruneOpts paths;
               initialize = false;
@@ -190,6 +197,13 @@ import ./make-test-python.nix (
           'restic-remotebackup snapshots --json | ${pkgs.jq}/bin/jq "length | . == 1"',
 
       )
+
+      # test that the inhibit option is working
+      server.systemctl("start --no-block restic-backups-inhibit-test.service")
+      server.wait_until_succeeds(
+          "systemd-inhibit --no-legend --no-pager | grep -q restic",
+          5
+      )
     '';
   }
 )