[backup] fix description

machines/fanny/configuration.nix

@@ -18,6 +18,7 @@ in
       inputs.self.nixosModules.malobeo.microvm
       inputs.self.nixosModules.malobeo.metrics
       inputs.self.nixosModules.malobeo.users
+      inputs.self.nixosModules.malobeo.backup
     ];
 
     virtualisation.vmVariantWithDisko = {
@@ -42,6 +43,11 @@ in
     cacheurl = "https://cache.dynamicdiscord.de";
   };
 
+  malobeo.backup = {
+    enable = true;
+    snapshots = [ "storage/encrypted" "zroot/encrypted/var" ];
+  };
+
   nix = {
     settings.experimental-features = [ "nix-command" "flakes" ];
     #always update microvms
@@ -53,6 +59,7 @@ in
   malobeo.users = {
     malobeo = true;
     admin = true;
+    backup = true;
   };
 
   malobeo.disks = {

machines/modules/malobeo/backup.nix

@@ -2,42 +2,66 @@
 with lib;
 let 
   cfg = config.malobeo.backup;
-  newfunc = (hostname: datasetNames: (map (dataset:  { name = "${hostname}_${dataset.sourceDataset}"; value = { inherit hostname; inherit dataset; }; } ) datasetNames));
+  hostToCommand = (hostname: datasetNames: 
+    (map (dataset:  { 
+      name = "${hostname}_${dataset.sourceDataset}";
+      value = { 
+        inherit hostname; 
+        inherit (dataset) sourceDataset targetDataset;
+      }; 
+    } ) datasetNames));
   peers = import ./peers.nix;
+
+  enableSnapshots = cfg.snapshots != null;
+  enableBackups = cfg.hosts != null;
 in
 {
   options.malobeo.backup = {
     enable = mkOption {
       type = types.bool;
       default = false;
-      description = "Enable sharing metrics";
+      description = "Enable sanoid/syncoid based backup functionality";
     };
 
     snapshots = mkOption {
-      type = types.listOf types.str;
-      default = [];
+      type = types.nullOr (types.listOf types.str);
+      default = null;
       description = "Automatic snapshots will be created for the given datasets";
     };
 
-    #TODO: instead listof str we need dataset here to declare the dataset name on the source host
-    #      and also the dataset name on target host (which stores the backups)
     hosts = mkOption {
-      type = types.attrsOf (types.listOf (types.submodule {
+      default = null;
+      type = types.nullOr (types.attrsOf (types.listOf (types.submodule {
         options = {
           sourceDataset = mkOption {
             type = types.str;
+            description = "The source that needs to be backed up";
           };
           targetDataset = mkOption {
             type = types.str;
+            description = "The target dataset where the backup should be stored";
           };
         };
-      }));
-      description = "Hostname with list of datasets to backup.";
+      })));
+      description = ''
+          Hostname with list of datasets to backup. This option should be defined on hosts that will store backups.
+
+          It is necessary to add the machines that get backed up to known hosts.
+          This can be done for example systemwide using 
+          programs.ssh.knownHosts."10.100.0.101" = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHqp2/YiiIhai7wyScGZJ20gtrzY+lp4N/8unyRs4qhc";
+          Or set it for the syncoid user directly.
+        '';
+    };
+
+    sshKey = mkOption {
+      default = null;
+      type = types.nullOr types.str;
+      description = "Set path to ssh key used for pull backups. Otherwise default key is used";
     };
   };
   
   config = mkIf (cfg.enable) {
-    services.sanoid = {
+    services.sanoid = mkIf (enableSnapshots) {
       enable = true;
   
       templates."default" = {
@@ -56,10 +80,9 @@ in
       }; }) cfg.snapshots);
     };
 
-    services.syncoid = with config; {
+    services.syncoid = mkIf (enableBackups) {
       enable = true;
-  
-      sshKey = sops.secrets.backup_key.path;
+      sshKey = cfg.sshKey;
   
       commonArgs = [
         "--no-sync-snap"
@@ -68,17 +91,12 @@ in
       interval = "*-*-* 04:15:00";
   
       commands = builtins.mapAttrs (name: value: {
-        source = "backup@${peers.${value.hostname}.address}:${value.dataset.sourceDataset}";
-        target = "${value.dataset.targetDataset}";
+        source = "backup@${peers.${value.hostname}.address}:${value.sourceDataset}";
+        target = "${value.targetDataset}";
         sendOptions = "w";
         recvOptions = "\"\"";
         recursive = true;
-      })(builtins.listToAttrs (builtins.concatLists (builtins.attrValues (builtins.mapAttrs newfunc cfg.hosts))));
-    };
-  
-    sops.secrets.backup_key = {
-      owner = config.services.syncoid.user;
-      key = "backup_key";
+      })(builtins.listToAttrs (builtins.concatLists (builtins.attrValues (builtins.mapAttrs hostToCommand cfg.hosts))));
     };
   };
 }

machines/modules/malobeo/users.nix

@@ -68,7 +68,7 @@ in
           users = [ "backup" ];
           commands = [
             {
-              command = "${pkgs.zfs-user}/bin/zfs";
+              command = "${pkgs.zfs}/bin/zfs";
               options = [ "NOPASSWD" ];
             }
           ];
@@ -94,4 +94,4 @@ in
       ];
     }
   ];
-}
+}