Added Folding@Home service

svn path=/nixos/trunk/; revision=23816

modules/misc/ids.nix

@@ -56,6 +56,7 @@ in
     sabnzbd = 33;
     tor = 35;
     cups = 36;
+    foldingAtHome = 37;
     # When adding a uid, make sure it doesn't match an existing gid.
 
     nixbld = 30000; # start of range of uids

modules/module-list.nix

@@ -62,6 +62,7 @@
   ./services/misc/autofs.nix
   ./services/misc/disnix.nix
   ./services/misc/felix.nix
+  ./services/misc/folding-at-home.nix
   ./services/misc/gpsd.nix
   ./services/misc/nix-daemon.nix
   ./services/misc/nix-gc.nix

modules/services/misc/folding-at-home.nix

@@ -0,0 +1,75 @@
+{ config, pkgs, ... }:
+with pkgs.lib;
+let
+  stateDir = "/var/lib/foldingathome";
+  cfg = config.services.foldingAtHome;
+  fahUser = "foldingathome";
+in {
+
+  ###### interface
+  
+  options = {
+  
+    services.foldingAtHome = {
+
+      enable = mkOption {
+        default = false;
+        description = ''
+          Whether to enable the Folding@Home to use idle CPU time.
+        '';
+      };
+
+      nickname = mkOption {
+        default = "Anonymous";
+        description = ''
+          A unique handle for statistics.
+        '';
+      };
+
+      config = mkOption {
+        default = "";
+        description = ''
+          Extra configuration. Contents will be added verbatim to the 
+          configuration file.
+        '';
+      };
+
+    };
+
+  };
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = [ pkgs.foldingathome ];
+
+    users.extraUsers = singleton
+      { name = fahUser;
+        uid = config.ids.uids.foldingAtHome;
+        description = "Folding@Home user";
+        home = stateDir;
+      };
+
+    jobs.foldingAtHome =
+      { name = "foldingathome";
+
+        startOn = "started network-interfaces";
+        stopOn = "stopping network-interfaces";
+
+        preStart =
+          ''
+            mkdir -m 0755 -p ${stateDir}
+            chown ${fahUser} ${stateDir}
+            cp -f ${pkgs.writeText "client.cfg" cfg.config} ${stateDir}/client.cfg
+          '';
+        exec = "${pkgs.su}/bin/su -s ${pkgs.stdenv.shell} ${fahUser} -c 'cd ${stateDir}; ${pkgs.foldingathome}/bin/fah6'";
+      };
+
+      services.foldingAtHome.config = ''
+          [settings]
+          username=${cfg.nickname}
+      '';
+
+  };
+
+}