Adds docs for planet puppet module

Change-Id: I4e1d70b36cfdc003e37c804bb2856b12449fefa3

doc/puppet.rst

@@ -82,8 +82,42 @@ The lodgeit module will automatically create a git repository in ``/var/backups/
    Ideally the SQL files would have a row on every line to keep the diffs stored
    in git small, but ``drizzledump`` does not yet support this.
 
+Planet
+------
+
+The planet module installs Planet Venus [5]_ along with required dependancies
+on a server.  It also configures specified planets based on options given.
+
+Planet Venus works by having a cron job which creates static files.  In this
+module the static files are served using nginx [4]_.
+
+To use this module you need to add something similar to the following into the
+main ``site.pp`` manifest:
+
+.. code-block:: ruby
+   :linenos:
+
+   node "planet.openstack.org" {
+     include planet
+
+     planet::site { "openstack":
+       git_url => "https://github.com/openstack/openstack-planet.git"
+     }
+   }
+
+In this example the name "openstack" is used to create the site
+``paste.openstack.org``.  The site will be served from
+``/srv/planet/openstack/`` and the checkout of the ``git_url`` supplied will
+be maintained in ``/var/lib/planet/openstack/``.
+
+This module will also create a cron job to pull new feed data 3 minutes past each hour.
+
+The ``git_url`` parameter needs to point to a git repository which stores the
+planet.ini configuration for the planet (which stores a list of feeds) and any required theme data.  This will be pulled every time puppet is run.
+
 .. rubric:: Footnotes
 .. [1] `Lodgeit homepage <http://www.pocoo.org/projects/lodgeit/>`_
 .. [2] `dcolish's Lodgeit fork <https://bitbucket.org/dcolish/lodgeit-main>`_
 .. [3] `Drizzle homepage <http://www.dirzzle.org/>`_
 .. [4] `nginx homepage <http://nginx.org/en/>`_
+.. [5] `Planet Venus <http://intertwingly.net/code/venus/docs/index.html>`_