Create symlink which is required for master node plugin tasks

Place where plugins are linked depends on configuration (of Nailgun,
MCollective, Astute), hence must not be hardcoded in specs and
should be done by puppet manifests which own master node configuration
details.

Change-Id: I1e9db92f9fc8dc70403113d1d6f9062b689dd2ee
Related-bug: #1603987
Closes-bug: #1648882
(cherry picked from commit 0bb6ffbcb5)

deployment/puppet/fuel/manifests/nailgun/server.pp

@@ -102,6 +102,14 @@ class fuel::nailgun::server (
     mode   => '0755',
   }
 
+  # NOTE(eli): In order for plugins to be run on master node
+  # without a need to hardcode full path, create a symlink
+  # so Nailgun can set CWD during execution of plugin tasks.
+  file {'/etc/fuel/plugins':
+    ensure => link,
+    target => '/var/www/nailgun/plugins',
+  }
+
   file { "/etc/nailgun/settings.yaml":
     content => template("fuel/nailgun/settings.yaml.erb"),
     owner   => 'root',