Move datasource query_retry into baseclass.

Moves the query_retry method into the baseclass and makes the query
retry and timeout options part of the watcher_datasources config group.
This makes the query_retry behavior uniform across all datasources.

A new baseclass method named query_retry_reset is added so datasources
can define operations to perform when recovering from a query error.
Test cases are added to verify the behavior of query_retry.

The query_max_retries and query_timeout config parameters are
deprecated in the gnocchi_client group and will be removed in a future
release.

Change-Id: I33e9dc2d1f5ba8f83fcf1488ff583ca5be5529cc

watcher/conf/datasources.py

@@ -34,7 +34,19 @@ DATASOURCES_OPTS = [
                      " the default for all strategies unless a strategy has a"
                      " specific override.",
                 item_type=cfg.types.String(choices=possible_datasources),
-                default=possible_datasources)
+                default=possible_datasources),
+    cfg.IntOpt('query_max_retries',
+               min=1,
+               default=10,
+               mutable=True,
+               help='How many times Watcher is trying to query again',
+               deprecated_group="gnocchi_client"),
+    cfg.IntOpt('query_timeout',
+               min=0,
+               default=1,
+               mutable=True,
+               help='How many seconds Watcher should wait to do query again',
+               deprecated_group="gnocchi_client")
     ]
 
 

watcher/conf/gnocchi_client.py

@@ -32,15 +32,8 @@ GNOCCHI_CLIENT_OPTS = [
                     'The default is public.'),
     cfg.StrOpt('region_name',
                help='Region in Identity service catalog to use for '
-                    'communication with the OpenStack service.'),
-    cfg.IntOpt('query_max_retries',
-               default=10,
-               mutable=True,
-               help='How many times Watcher is trying to query again'),
-    cfg.IntOpt('query_timeout',
-               default=1,
-               mutable=True,
-               help='How many seconds Watcher should wait to do query again')]
+                    'communication with the OpenStack service.')
+]
 
 
 def register_opts(conf):