Add policy sample file in doc

policy sample file with all the default rules
commented out is missing in glance doc which can be
used for reference or when few rules needs to
be overriden (and keep all other default rule commented
out).

Change-Id: I0cc461f7061358389186ac4751f6e037e1bf6dc7

doc/source/conf.py

@@ -33,6 +33,7 @@ extensions = [
     'sphinx.ext.viewcode',
     'oslo_config.sphinxext',
     'oslo_config.sphinxconfiggen',
+    'oslo_policy.sphinxpolicygen',
     'openstackdocstheme',
     'sphinxcontrib.apidoc',
 ]
@@ -65,6 +66,10 @@ config_generator_config_file = [
      '_static/glance-scrubber'),
 ]
 
+policy_generator_config_file = [
+    ('../../etc/glance-policy-generator.conf', '_static/glance'),
+]
+
 # The master toctree document.
 master_doc = 'index'
 

doc/source/configuration/sample-configuration.rst

@@ -43,3 +43,20 @@ This sample configuration can also be viewed in `glance-cache.conf.sample
 <../_static/glance-cache.conf.sample>`_.
 
 .. literalinclude:: ../_static/glance-cache.conf.sample
+
+
+Sample Policy File for Glance
+-----------------------------
+
+The following is a Glance sample policy file for adaptation and use.
+
+The sample policy can also be viewed in :download:`file form
+<../_static/glance.policy.yaml.sample>`.
+
+.. important::
+
+   The sample policy file is auto-generated from glance when this documentation
+   is built. You must ensure your version of glance matches the version of this
+   documentation.
+
+.. literalinclude:: ../_static/glance.policy.yaml.sample