Change shards & catalogue db into single property

Refactoring the shards and catalogue mongo database methods into a
single method because there's no need for these to access different
logical databases.

Change-Id: Ia75df73dcdb31e88473878f6c55abcf159f1aa44
Closes-Bug: #1246373

marconi/queues/storage/mongodb/catalogue.py

@@ -42,7 +42,7 @@ class CatalogueController(base.CatalogueBase):
     def __init__(self, *args, **kwargs):
         super(CatalogueController, self).__init__(*args, **kwargs)
 
-        self._col = self.driver.catalogue_database.catalogue
+        self._col = self.driver.database.catalogue
         self._col.ensure_index(CATALOGUE_INDEX, unique=True)
 
     @utils.raises_conn_error

marconi/queues/storage/mongodb/driver.py

@@ -126,25 +126,14 @@ class ControlDriver(storage.ControlDriverBase):
         return _connection(self.mongodb_conf)
 
     @decorators.lazy_property(write=False)
-    def shards_database(self):
-        name = self.mongodb_conf.database + '_shards'
+    def database(self):
+        name = self.mongodb_conf.database
         return self.connection[name]
 
     @property
     def shards_controller(self):
         return controllers.ShardsController(self)
 
-    @decorators.lazy_property(write=False)
-    def catalogue_database(self):
-        """Database dedicated to the "queues" collection.
-
-        The queues collection is separated out into its own database
-        to avoid writer lock contention with the messages collections.
-        """
-
-        name = self.mongodb_conf.database + '_catalogue'
-        return self.connection[name]
-
     @property
     def catalogue_controller(self):
         return controllers.CatalogueController(self)

marconi/queues/storage/mongodb/shards.py

@@ -48,7 +48,7 @@ class ShardsController(base.ShardsBase):
     def __init__(self, *args, **kwargs):
         super(ShardsController, self).__init__(*args, **kwargs)
 
-        self._col = self.driver.shards_database.shards
+        self._col = self.driver.database.shards
         self._col.ensure_index(SHARDS_INDEX,
                                background=True,
                                name='shards_name',