restic: add daily external backups of all safe/backups

shared/applications/server/restic.nix

@@ -0,0 +1,30 @@
+{ config, lib, ... }:
+
+{
+  services.restic = {
+    # enable = true;
+    
+    backups.main  = {
+      repository = "b2:situla-${config.mine.shared.settings.brand_lower}:.";
+
+      passwordFile = config.age.secrets."restic-pass".path;
+      environmentFile = config.age.secrets."restic-env".path;
+
+      # take all `.*/safe/.*` and `.*/backup/.*` zfs volumes
+      paths = let
+        backupPaths = lib.filterAttrs (n: _:
+          (lib.hasInfix "/safe/" n) || (lib.hasInfix "/backup/" n)
+        ) config.mine.zfsMounts;
+      in lib.attrValues backupPaths;
+
+      initialize = true;
+      runCheck = true;
+      pruneOpts = [
+        "--keep-last 7"
+        "--keep-weekly 4"
+        "--keep-monthly 6"
+        "--keep-yearly 2"
+      ];
+    };
+  };
+}