backwards: Backup sync to external drive with restic

hosts/backwards/modules/default.nix

@@ -13,6 +13,7 @@ in
       ssh.enable = true;
       git.enable = true;
       syncthing.enable = true;
+      restic.enable = true;
     };
   };
 }

hosts/backwards/modules/restic/default.nix

@@ -0,0 +1,50 @@
+{ lib, config, ... }:
+let
+  enabled = config.mod.restic.enable;
+in
+{
+  options = {
+    mod.restic = {
+      enable = lib.mkEnableOption "Enable restic";
+    };
+  };
+
+  config = lib.mkIf enabled {
+    fileSystems."/home/alex/backup" = {
+      device = "/dev/disk/by-uuid/34601701-65e6-4b2c-ac4d-8bef3dfd743f";
+      fsType = "ext4";
+      options = [ "nofail" ];
+    };
+
+    services = {
+      restic.backups = {
+        "sync-to-external" = {
+          initialize = true;
+
+          passwordFile = config.age.secrets.restic-password.path;
+
+          paths = [ "/home/alex/sync" ];
+          repository = "/home/alex/backup/restic";
+
+          timerConfig = {
+            OnCalendar = "*-*-* 0/12:00:00"; # Every 12th hour, i.e. twice a day
+            Persistent = true;
+          };
+
+          pruneOpts = [
+            "--keep-daily 1"
+            "--keep-weekly 7"
+            "--keep-yearly 12"
+          ];
+        };
+      };
+    };
+
+    age = {
+      secrets = {
+        "restic-password".file = ../../../../secrets/backwards/restic-password.age;
+      };
+    };
+  };
+}
+