Implement event list nested-depth

The GET call to list events will support a nested_depth parameter. The
response will have an additional links url with the ref 'root_stack'
to indicate that this API supports nested_depth queries.

This has the following consequences for old/new combinations of
client/server
- new heatclient, new server - nested_depth param is set, server
  returns nested events
- new heatclient, old server - nested_depth param is set, server
  returns events with no root_stack, heatclient falls back to
  recursive event fetch
- old heatclient, new server - nested_depth param is never set,
  recursive event fetch works as before

Here are some timings for a TripleO overcloud stack with ~700 events.

Current heat and python-heatclient master:
time openstack stack event list --nested-depth 4 overcloud |wc -l
744
real    0m17.500s

This change, with heatclient 31278ff5f77b152b5ef7a4197e15c441c72ff163:
time openstack stack event list --nested-depth 4 overcloud  |wc -l
608
real    0m1.725s

The difference in event count (744 vs 608) is due to the stack events
being filtered out for stacks with zero resources - these are a source
of unnecessary noise so their removal should be considered an improvement.

Closes-Bug: #1588561

Change-Id: I27e1ffb770e00a7f929c081b2a505e2007f5d584

1 files changed, 21 insertions, 11 deletions

diff --git a/heat/api/openstack/v1/events.py b/heat/api/openstack/v1/events.py
index d1d40a561..9cfc14f3f 100644
--- a/heat/api/openstack/v1/events.py
+++ b/heat/api/openstack/v1/events.py
@@ -69,9 +69,15 @@ def format_event(req, event, keys=None):
         else:
             yield (key, value)
 
-    return dict(itertools.chain.from_iterable(
+    ev = dict(itertools.chain.from_iterable(
         transform(k, v) for k, v in event.items()))
 
+    root_stack_id = event.get(rpc_api.EVENT_ROOT_STACK_ID)
+    if root_stack_id:
+        root_identifier = identifier.HeatIdentifier(**root_stack_id)
+        ev['links'].append(util.make_link(req, root_identifier, 'root_stack'))
+    return ev
+
 
 class EventController(object):
     """WSGI controller for Events in Heat v1 API.
@@ -86,14 +92,16 @@ class EventController(object):
         self.rpc_client = rpc_client.EngineClient()
 
     def _event_list(self, req, identity, detail=False, filters=None,
-                    limit=None, marker=None, sort_keys=None, sort_dir=None):
+                    limit=None, marker=None, sort_keys=None, sort_dir=None,
+                    nested_depth=None):
         events = self.rpc_client.list_events(req.context,
                                              identity,
                                              filters=filters,
                                              limit=limit,
                                              marker=marker,
                                              sort_keys=sort_keys,
-                                             sort_dir=sort_dir)
+                                             sort_dir=sort_dir,
+                                             nested_depth=nested_depth)
         keys = None if detail else summary_keys
 
         return [format_event(req, e, keys) for e in events]
@@ -106,6 +114,7 @@ class EventController(object):
             'marker': util.PARAM_TYPE_SINGLE,
             'sort_dir': util.PARAM_TYPE_SINGLE,
             'sort_keys': util.PARAM_TYPE_MULTI,
+            'nested_depth': util.PARAM_TYPE_SINGLE,
         }
         filter_whitelist = {
             'resource_status': util.PARAM_TYPE_MIXED,
@@ -115,14 +124,15 @@ class EventController(object):
         }
         params = util.get_allowed_params(req.params, whitelist)
         filter_params = util.get_allowed_params(req.params, filter_whitelist)
-        key = rpc_api.PARAM_LIMIT
-        if key in params:
-            try:
-                limit = param_utils.extract_int(key, params[key],
-                                                allow_zero=True)
-            except ValueError as e:
-                raise exc.HTTPBadRequest(six.text_type(e))
-            params[key] = limit
+
+        int_params = (rpc_api.PARAM_LIMIT, rpc_api.PARAM_NESTED_DEPTH)
+        try:
+            for key in int_params:
+                if key in params:
+                    params[key] = param_utils.extract_int(
+                        key, params[key], allow_zero=True)
+        except ValueError as e:
+            raise exc.HTTPBadRequest(six.text_type(e))
 
         if resource_name is None:
             if not filter_params: