Factor out duplicated notification sample data

Versioned notifications are functionally tested against stored sample
data. Also most of the instance notitication shares payload structure.
Today we store a separate sample for every instance notification.
These samples store similar, mostly redundant data. When a new field
is added to the InstancePayload then every instance notification
related sample file needs to be modified. This leads to big and
redundant changes like I18af99479562e2fe5e74e6e1252b804b074fee58.

To remove the redundancy this patch proposes to use json references
in the sample files instead of copy pasting the same notification
sample fragment to every sample.

As a first step this patch introduces a small json ref resolver.
Then subsequent patches will replace the duplicated sample data
with references to common sample fragments.

This proposed resolver supports resolving the refs recursively so
a referenced json fragment can reference further fragments. However
the current implementation does not handle reference loops.
The resolver also supports overriding parts of the referenced
json fragment to support content customization needed in the next
patch.

Change-Id: Ic3ab7d60e4ac12b767fe70bef97b327545a86e74

1 files changed, 13 insertions, 2 deletions

diff --git a/doc/ext/versioned_notifications.py b/doc/ext/versioned_notifications.py
index ae457544a3..dee53445a1 100644
--- a/doc/ext/versioned_notifications.py
+++ b/doc/ext/versioned_notifications.py
@@ -19,15 +19,18 @@ It is used via a single directive in the .rst file
   .. versioned_notifications::
 
 """
+import os
 
 from docutils import nodes
 from docutils.parsers import rst
 import importlib
+from oslo_serialization import jsonutils
 import pkgutil
 
-import nova.notifications.objects
 from nova.notifications.objects import base as notification
 from nova.objects import base
+from nova.tests import json_ref
+import nova.utils
 
 
 class VersionedNotificationDirective(rst.Directive):
@@ -125,9 +128,17 @@ jQuery(document).ready(function(){
             col = nodes.entry()
             row.append(col)
 
-            with open(self.SAMPLE_ROOT + sample_file, 'r') as f:
+            with open(os.path.join(self.SAMPLE_ROOT, sample_file), 'r') as f:
                 sample_content = f.read()
 
+            sample_obj = jsonutils.loads(sample_content)
+            sample_obj = json_ref.resolve_refs(
+                sample_obj,
+                base_path=os.path.abspath(self.SAMPLE_ROOT))
+            sample_content = jsonutils.dumps(sample_obj,
+                                             sort_keys=True, indent=4,
+                                             separators=(',', ': '))
+
             event_type = sample_file[0: -5]
             html_str = self.TOGGLE_SCRIPT % ((event_type, ) * 3)
             html_str += ("<input type='button' id='%s-hideshow' "