1 files changed, 90 insertions, 0 deletions
diff --git a/nixos/modules/services/backup/zfs-replication.nix b/nixos/modules/services/backup/zfs-replication.nix
new file mode 100644
index 00000000000..6d75774c78f
--- /dev/null
+++ b/nixos/modules/services/backup/zfs-replication.nix
@@ -0,0 +1,90 @@
+{ lib, pkgs, config, ... }:
+
+with lib;
+
+let
+  cfg = config.services.zfs.autoReplication;
+  recursive = optionalString cfg.recursive " --recursive";
+  followDelete = optionalString cfg.followDelete " --follow-delete";
+in {
+  options = {
+    services.zfs.autoReplication = {
+      enable = mkEnableOption "ZFS snapshot replication.";
+
+      followDelete = mkOption {
+        description = "Remove remote snapshots that don't have a local correspondant.";
+        default = true;
+        type = types.bool;
+      };
+
+      host = mkOption {
+        description = "Remote host where snapshots should be sent. <literal>lz4</literal> is expected to be installed on this host.";
+        example = "example.com";
+        type = types.str;
+      };
+
+      identityFilePath = mkOption {
+        description = "Path to SSH key used to login to host.";
+        example = "/home/username/.ssh/id_rsa";
+        type = types.path;
+      };
+
+      localFilesystem = mkOption {
+        description = "Local ZFS fileystem from which snapshots should be sent.  Defaults to the attribute name.";
+        example = "pool/file/path";
+        type = types.str;
+      };
+
+      remoteFilesystem = mkOption {
+        description = "Remote ZFS filesystem where snapshots should be sent.";
+        example = "pool/file/path";
+        type = types.str;
+      };
+
+      recursive = mkOption {
+        description = "Recursively discover snapshots to send.";
+        default = true;
+        type = types.bool;
+      };
+
+      username = mkOption {
+        description = "Username used by SSH to login to remote host.";
+        example = "username";
+        type = types.str;
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = [
+      pkgs.lz4
+    ];
+
+    systemd.services.zfs-replication = {
+      after = [
+        "zfs-snapshot-daily.service"
+        "zfs-snapshot-frequent.service"
+        "zfs-snapshot-hourly.service"
+        "zfs-snapshot-monthly.service"
+        "zfs-snapshot-weekly.service"
+      ];
+      description = "ZFS Snapshot Replication";
+      documentation = [
+        "https://github.com/alunduil/zfs-replicate"
+      ];
+      restartIfChanged = false;
+      serviceConfig.ExecStart = "${pkgs.zfs-replicate}/bin/zfs-replicate${recursive} -l ${escapeShellArg cfg.username} -i ${escapeShellArg cfg.identityFilePath}${followDelete} ${escapeShellArg cfg.host} ${escapeShellArg cfg.remoteFilesystem} ${escapeShellArg cfg.localFilesystem}";
+      wantedBy = [
+        "zfs-snapshot-daily.service"
+        "zfs-snapshot-frequent.service"
+        "zfs-snapshot-hourly.service"
+        "zfs-snapshot-monthly.service"
+        "zfs-snapshot-weekly.service"
+      ];
+    };
+  };
+
+  meta = {
+    maintainers = with lib.maintainers; [ alunduil ];
+  };
+}