1 files changed, 95 insertions, 0 deletions

diff --git a/modules/zfssnap/default.nix b/modules/zfssnap/default.nix
new file mode 100644
index 00000000..a0590c9f
--- /dev/null
+++ b/modules/zfssnap/default.nix
@@ -0,0 +1,95 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+  
+let
+  zfssnap = pkgs.stdenv.mkDerivation rec {
+    name = "zfssnap";
+    src = ./zfssnap.py;
+
+    phases = [ "buildPhase" "checkPhase" "installPhase" ];
+
+    buildInputs = with pkgs; [makeWrapper];
+
+    python = pkgs.python39.withPackages (ps: with ps; [pyxdg pytimeparse dateutil systemd]);
+
+    buildPhase = ''
+      substitute $src zfssnap \
+        --subst-var-by python ${escapeShellArg python}
+    '';
+
+    doCheck = true;
+    checkPhase = ''
+      ${python}/bin/python -m py_compile zfssnap
+    '';
+
+    installPhase = ''
+      install -m 0755 -D -t $out/bin \
+        zfssnap
+
+      wrapProgram $out/bin/zfssnap \
+        --prefix PATH : ${makeBinPath [config.boot.zfs.package]}
+    '';
+  };
+
+  cfg = config.services.zfssnap;
+in {
+  options = {
+    services.zfssnap = {
+      enable = mkEnableOption "zfssnap service";
+      
+      config = mkOption {
+        type = with types; attrsOf (attrsOf str);
+        default = {
+          keep = {
+            within = "5m";
+            "5m" = "24";
+            hourly = "24";
+            daily = "31";
+            monthly = "24";
+            yearly = "-1";
+          };
+        };
+      };
+
+      snapInterval = mkOption {
+        type = types.str;
+        default = "*-*-* *:00/5:00 Europe/Berlin";
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services."zfssnap" = {
+      description = "Create automatic ZFS snapshots";
+      after = [ "zfs-import.target" ];
+      wants = [ "zfssnap-prune.service" ];
+      before = [ "zfssnap-prune.service" ];
+      serviceConfig = {
+        Type = "oneshot";
+        ExecStart = "${zfssnap}/bin/zfssnap --no-stderr -vv";
+      };
+    };
+    systemd.services."zfssnap-prune" = {
+      description = "Prune automatic ZFS snapshots";
+      after = [ "zfs-import.target" "zfssnap.service" ];
+      serviceConfig = {
+        Type = "oneshot";
+        ExecStart = let
+          mkSectionName = name: strings.escape [ "[" "]" ] (strings.toUpper name);
+          zfssnapConfig = generators.toINI { inherit mkSectionName; } cfg.config;
+        in "${zfssnap}/bin/zfssnap --no-stderr -vv prune --config=${zfssnapConfig}";
+      };
+    };
+
+    systemd.timers."zfssnap" = {
+      wantedBy = ["timers.target"];
+      timerConfig = {
+        OnCalendar = cfg.snapInterval;
+        Persistent = true;
+      };
+    };
+
+    environment.systemPackages = [zfssnap];
+  };
+}