From f4a6f9e84bd51611a924aecf6c7c23e149f13215 Mon Sep 17 00:00:00 2001
From: Nicolas Pierron <nicolas.b.pierron@gmail.com>
Date: Fri, 4 Dec 2009 12:50:44 +0000
Subject: [PATCH] * Add options to handle automatic calls to the garbage
 collector.

  These options avoid manual references to pkgs.nixUnstable which might be
  changed with environment.nix option.

svn path=/nixos/trunk/; revision=18798
---
 modules/module-list.nix          |  1 +
 modules/services/misc/nix-gc.nix | 54 ++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 modules/services/misc/nix-gc.nix

diff --git a/modules/module-list.nix b/modules/module-list.nix
index f80d4d6a586..d793c715202 100644
--- a/modules/module-list.nix
+++ b/modules/module-list.nix
@@ -54,6 +54,7 @@
   ./services/misc/disnix.nix
   ./services/misc/gpsd.nix
   ./services/misc/nix-daemon.nix
+  ./services/misc/nix-gc.nix
   ./services/misc/nixos-manual.nix
   ./services/misc/rogue.nix
   ./services/misc/synergy.nix
diff --git a/modules/services/misc/nix-gc.nix b/modules/services/misc/nix-gc.nix
new file mode 100644
index 00000000000..942e7996da0
--- /dev/null
+++ b/modules/services/misc/nix-gc.nix
@@ -0,0 +1,54 @@
+{ config, pkgs, ... }:
+
+with pkgs.lib;
+
+let
+  nix = config.environment.nix;
+  cfg = config.nix.gc;
+in
+
+{
+
+  ###### interface
+
+  options = {
+    nix.gc = {
+
+      automatic = mkOption {
+        default = false;
+        example = true;
+        description = "
+          Automatically run the garbage collector at specified dates.
+        ";
+      };
+
+      dates = mkOption {
+        default = "15 03 * * *";
+        description = "
+          Run the garbage collector at specified dates to avoid full
+          hard-drives.
+        ";
+      };
+
+      options = mkOption {
+        default = "";
+        example = "--max-freed $((64 * 1024**3))";
+        description = "
+          Options given to <filename>nix-collect-garbage</filename> when the
+          garbage collector is run automatically.
+        ";
+      };
+
+    };
+  };
+
+
+  ###### implementation
+
+  config = mkIf cfg.automatic {
+    services.cron.systemCronJobs = [
+      "${cfg.dates} root ${nix}/bin/nix-collect-garbage ${cfg.options} > /var/log/gc.log 2>&1"
+    ];
+  };
+
+}