Add MongoDB example service

examples/services-agnostic/constructors.nix

@@ -62,4 +62,14 @@ in
     inherit createManagedProcess stateDir runtimeDir cacheDir forceDisableUserChange;
     inherit (pkgs) stdenv writeTextFile nginx;
   };
+
+  mongodb = import ./mongodb.nix {
+    inherit createManagedProcess runtimeDir;
+    inherit (pkgs) mongodb;
+  };
+
+  simplemongodb = import ./simplemongodb.nix {
+    inherit createManagedProcess runtimeDir stateDir forceDisableUserChange;
+    inherit (pkgs) stdenv mongodb writeTextFile;
+  };
 }

examples/services-agnostic/mongodb.nix

@@ -0,0 +1,34 @@
+{createManagedProcess, mongodb, runtimeDir}:
+{instanceSuffix ? "", configFile, initialize ? "", postInstall ? ""}:
+
+let
+  instanceName = "mongodb${instanceSuffix}";
+  user = instanceName;
+  group = instanceName;
+in
+createManagedProcess {
+  name = instanceName;
+  inherit instanceName initialize postInstall;
+  process = "${mongodb}/bin/mongod";
+  args = [ "--config" configFile ];
+  daemonExtraArgs = [ "--fork" "--pidfilepath" "${runtimeDir}/${instanceName}.pid" ];
+  user = instanceName;
+
+  credentials = {
+    groups = {
+      "${group}" = {};
+    };
+    users = {
+      "${user}" = {
+        inherit group;
+        description = "MongoDB user";
+      };
+    };
+  };
+
+  overrides = {
+    sysvinit = {
+      runlevels = [ 3 4 5 ];
+    };
+  };
+}

examples/services-agnostic/processes.nix

@@ -3,6 +3,7 @@
 , stateDir ? "/var"
 , runtimeDir ? "${stateDir}/run"
 , logDir ? "${stateDir}/log"
+, cacheDir ? "${stateDir}/cache"
 , tmpDir ? (if stateDir == "/var" then "/tmp" else "${stateDir}/tmp")
 , forceDisableUserChange ? false
 , processManager ? "sysvinit"
@@ -10,7 +11,7 @@
 
 let
   constructors = import ./constructors.nix {
-    inherit pkgs stateDir runtimeDir logDir tmpDir forceDisableUserChange processManager;
+    inherit pkgs stateDir runtimeDir logDir tmpDir cacheDir forceDisableUserChange processManager;
   };
 in
 rec {
@@ -45,4 +46,8 @@ rec {
       inherit httpPort;
     };
   };
+
+  simplemongodb = rec {
+    pkg = constructors.simplemongodb {};
+  };
 }

examples/services-agnostic/simplemongodb.nix

@@ -0,0 +1,29 @@
+{createManagedProcess, stdenv, writeTextFile, mongodb, runtimeDir, stateDir, forceDisableUserChange}:
+{instanceSuffix ? "", bindIP ? "127.0.0.1", port ? 27017, postInstall ? ""}:
+
+let
+  instanceName = "mongodb${instanceSuffix}";
+  mongodbDir = "${stateDir}/db/${instanceName}";
+  user = instanceName;
+  group = instanceName;
+in
+import ./mongodb.nix {
+  inherit createManagedProcess mongodb runtimeDir;
+} {
+  inherit instanceSuffix postInstall;
+  configFile = writeTextFile {
+    name = "mongodb.conf";
+    text = ''
+      systemLog.destination: syslog
+      storage.dbPath: ${mongodbDir}
+      net.bindIp: ${bindIP}
+      net.port: ${toString port}
+    '';
+  };
+  initialize = ''
+    mkdir -p ${mongodbDir}
+    ${stdenv.lib.optionalString (!forceDisableUserChange) ''
+      chown ${user}:${group} ${mongodbDir}
+    ''}
+  '';
+}