Move from features to option based configuration

modules/nix/backup.nix

@@ -0,0 +1,74 @@
+{ pkgs
+, lib
+, config
+, ...
+}:
+
+with lib; let
+    cfg = config.simmer.backup;
+in
+{
+    options.simmer.backup = {
+        enable = mkOption {
+            description = "Whether backups should be enabled";
+            type = types.bool;
+            default = false;
+        };
+
+        repo = mkOption {
+            description = "Which repository to backup to";
+            type = types.str;
+        };
+
+        paths = mkOption {
+            description = "Which paths to backup";
+            type = types.listOf types.str;
+        };
+
+        user = mkOption {
+            description = "Which user to run backup commands with";
+            type = types.str;
+            default = "root";
+        };
+
+        excludes = mkOption {
+            description = "Which directories to exclude";
+            type = types.listOf types.str;
+            default = [];
+        };
+
+        passphrase = mkOption {
+            description = "path to file containing passphrase";
+            type = types.path;
+        };
+
+        key = mkOption {
+            description = "Path to file containing SSH Key";
+            type = types.path;
+        };
+
+        repeat = mkOption {
+            description = "How often to run the backup (hourly, daily, weekly)";
+            type = types.enum [ "hourly" "daily" "weekly" ];
+        };
+
+    };
+
+    config = mkIf cfg.enable {
+        services.borgbackup.jobs = {
+            backup = {
+                user = cfg.user;
+                paths = cfg.paths;
+                exclude = cfg.excludes;
+                repo = cfg.repo;
+                encryption = {
+                    mode = "repokey-blake2";
+                    passCommand = "cat ${cfg.passphrase}";
+                };
+                environment.BORG_RSH = "ssh -i ${cfg.key}";
+                compression = "auto,lzma";
+                startAt = cfg.repeat;
+            };
+        };
+    };
+}