Add ulimit module.

A new module that provides a define to add a file to
/etc/security/limits.d for each limit line defined. This can be used
to limit the number of processes a user can have.

Change-Id: I7d1074ec85dbf3e212c0eccbe4e6e926b56f561c

modules/ulimit/manifests/conf.pp

@@ -0,0 +1,17 @@
+define ulimit::conf (
+  $limit_domain,
+  $limit_item,
+  $limit_value,
+  $limit_type = 'soft',
+) {
+
+  file { "/etc/security/limits.d/99-${limit_domain}-${limit_type}-${limit_item}.conf":
+    ensure  => present,
+    content => template('ulimit/limits.erb'),
+    replace => true,
+    owner   => 'root',
+    mode    => 0644,
+    require => File['/etc/security/limits.d']
+  }
+
+}

modules/ulimit/manifests/init.pp

@@ -0,0 +1,13 @@
+class ulimit {
+
+  package { ['libpam-modules', 'libpam-modules-bin']:
+    ensure => present
+  }
+
+  file { '/etc/security/limits.d':
+    ensure => directory,
+    owner  => 'root',
+    mode   => 0755
+  }
+
+}

modules/ulimit/templates/limits.erb

@@ -0,0 +1,2 @@
+# This file is managed by puppet. Manual changes will be ignored.
+<%= limit_domain %> <%= limit_type %> <%= limit_item %> <%= limit_value %>