Enable pooling in devstack

This patch enables pooling by default. Pooling has become a central
piece for Zaqar, therefore, we ought to test on it always.

The patch also changes the behavior for pools in Zaqar. That is,
whenever a default pool is not found and a `message_store` section has
been configured, such section will be used as the default store. No
pools will be created out of this configurations so that users can still
configure their default store using zaqarclient.

Change-Id: I820ac017ee44b806dead9bc484664228d4022f81
Depends-On: If5c91ebe136017cea2eeecf62a580d050e49617d

devstack/plugin.sh

@@ -118,14 +118,20 @@ function configure_zaqar {
     iniset $ZAQAR_CONF DEFAULT unreliable True
     iniset $ZAQAR_CONF DEFAULT admin_mode True
     iniset $ZAQAR_CONF DEFAULT use_syslog $SYSLOG
+
+    # Enable pooling by default for now
+    iniset $ZAQAR_CONF DEFAULT admin_mode True
     iniset $ZAQAR_CONF 'drivers:transport:wsgi' bind $ZAQAR_SERVICE_HOST
 
     configure_auth_token_middleware $ZAQAR_CONF zaqar $ZAQAR_AUTH_CACHE_DIR
 
     if [ "$ZAQAR_BACKEND" = 'mongodb' ] ; then
+        iniset $ZAQAR_CONF DEFAULT pooling True
         iniset $ZAQAR_CONF  drivers storage mongodb
         iniset $ZAQAR_CONF 'drivers:message_store:mongodb' uri mongodb://localhost:27017/zaqar
         iniset $ZAQAR_CONF 'drivers:message_store:mongodb' database zaqar
+        iniset $ZAQAR_CONF 'drivers:management_store:mongodb' uri mongodb://localhost:27017/zaqar_mgmt
+        iniset $ZAQAR_CONF 'drivers:management_store:mongodb' database zaqar_mgmt
         configure_mongodb
     elif [ "$ZAQAR_BACKEND" = 'redis' ] ; then
         iniset $ZAQAR_CONF  drivers storage redis

zaqar/storage/pooling.py

@@ -415,7 +415,7 @@ class Catalog(object):
         self._catalogue_ctrl = control.catalogue_controller
 
     # FIXME(cpp-cabrera): https://bugs.launchpad.net/zaqar/+bug/1252791
-    def _init_driver(self, pool_id):
+    def _init_driver(self, pool_id, pool_conf=None):
         """Given a pool name, returns a storage driver.
 
         :param pool_id: The name of a pool.
@@ -423,7 +423,10 @@ class Catalog(object):
         :returns: a storage driver
         :rtype: zaqar.storage.base.DataDriverBase
         """
-        pool = self._pools_ctrl.get(pool_id, detailed=True)
+        if pool_id is not None:
+            pool = self._pools_ctrl.get(pool_id, detailed=True)
+        else:
+            pool = pool_conf
         conf = utils.dynamic_conf(pool['uri'], pool['options'],
                                   conf=self._conf)
         storage = utils.load_storage_driver(conf,
@@ -581,15 +584,30 @@ class Catalog(object):
         except errors.QueueNotMapped as ex:
             LOG.debug(ex)
 
-            # NOTE(kgriffs): Return `None`, rather than letting the
+            conf_section = ('drivers:message_store:%s' %
-            # exception bubble up, so that the higher layer doesn't
+                            self._conf.drivers.storage)
-            # have to duplicate the try..except..log code all over
+
-            # the place.
+            if conf_section not in self._conf:
-            return None
+                # NOTE(kgriffs): Return `None`, rather than letting the
+                # exception bubble up, so that the higher layer doesn't
+                # have to duplicate the try..except..log code all over
+                # the place.
+                return None
+
+            # NOTE(flaper87): This assumes the storage driver type is the
+            # same as the management.
+            pool_conf = {'uri': self._conf[conf_section].uri,
+                         'options': {}}
+
+            # NOTE(flaper87): This will be using the config
+            # storage configuration as the default one if no
+            # default storage has been registered in the pool
+            # store.
+            return self.get_driver(None, pool_conf)
 
         return self.get_driver(pool_id)
 
-    def get_driver(self, pool_id):
+    def get_driver(self, pool_id, pool_conf=None):
         """Get storage driver, preferably cached, from a pool name.
 
         :param pool_id: The name of a pool.
@@ -602,6 +620,6 @@ class Catalog(object):
             return self._drivers[pool_id]
         except KeyError:
             # NOTE(cpp-cabrera): cache storage driver connection
-            self._drivers[pool_id] = self._init_driver(pool_id)
+            self._drivers[pool_id] = self._init_driver(pool_id, pool_conf)
 
             return self._drivers[pool_id]