munin: Add a helper resource definition for munin plugins.

puppet/zulip_ops/manifests/munin_plugin.pp

@@ -0,0 +1,15 @@
+define zulip_ops::munin_plugin {
+  file { "/usr/local/munin/lib/plugins/${title}":
+    owner  => 'root',
+    group  => 'root',
+    mode   => '0755',
+    source => "puppet:///modules/zulip_ops/munin-plugins/${title}",
+  }
+
+  file { "/etc/munin/plugins/${name}":
+    ensure  => 'link',
+    require => File["/usr/local/munin/lib/plugins/${title}"],
+    target  => "/usr/local/munin/lib/plugins/${title}",
+    notify  => Service['munin-node'],
+  }
+}