Merge pull request #185 from ocharles/memcached

memcached: Add NixOS support

modules/module-list.nix

@@ -74,6 +74,7 @@
   ./services/backup/sitecopy-backup.nix
   ./services/databases/4store-endpoint.nix
   ./services/databases/4store.nix
+  ./services/databases/memcached.nix
   ./services/databases/mongodb.nix
   ./services/databases/redis.nix
   ./services/databases/mysql.nix

modules/services/databases/memcached.nix

@@ -0,0 +1,97 @@
+{ config, pkgs, ... }:
+
+with pkgs.lib;
+
+let
+
+  cfg = config.services.memcached;
+
+  memcached = pkgs.memcached;
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.memcached = {
+
+      enable = mkOption {
+        default = false;
+        description = "
+          Whether to enable Memcached.
+        ";
+      };
+
+      user = mkOption {
+        default = "memcached";
+        description = "The user to run Memcached as";
+      };
+
+      listen = mkOption {
+        default = "127.0.0.1";
+        description = "The IP address to bind to";
+      };
+
+      port = mkOption {
+        default = 11211;
+        description = "The port to bind to";
+      };
+
+      socket = mkOption {
+        default = "";
+        description = "Unix socket path to listen on. Setting this will disable network support";
+        example = "/var/run/memcached";
+      };
+
+      maxMemory = mkOption {
+        default = 64;
+        description = "The maximum amount of memory to use for storage, in megabytes.";
+      };
+
+      maxConnections = mkOption {
+        default = 1024;
+        description = "The maximum number of simultaneous connections";
+      };
+
+      extraOptions = mkOption {
+        default = [];
+        description = "A list of extra options that will be added as a suffix when running memcached";
+      };
+    };
+
+  };
+
+  ###### implementation
+
+  config = mkIf config.services.memcached.enable {
+
+    users.extraUsers = singleton
+      { name = cfg.user;
+        description = "Memcached server user";
+      };
+
+    environment.systemPackages = [ memcached ];
+
+    systemd.services.memcached =
+      { description = "Memcached server";
+
+        wantedBy = [ "multi-user.target" ];
+        after = [ "network.target" ];
+
+        serviceConfig = {
+          ExecStart =
+            let
+              networking = if cfg.socket != ""
+                then "-s ${cfg.socket}"
+                else "-l ${cfg.listen} -p ${toString cfg.port}";
+            in "${memcached}/bin/memcached ${networking} -m ${toString cfg.maxMemory} -c ${toString cfg.maxConnections} ${concatStringsSep " " cfg.extraOptions}";
+
+          User = cfg.user;
+        };
+      };
+  };
+
+}