api: build the storage connection once and for all

Fixes: bug#1178845

Change-Id: Ic0c639224ba87c3e11f3e1eeba4915e3c8ba0e88

ceilometer/api/app.py

@@ -26,6 +26,7 @@ from ceilometer.api import config as api_config
 from ceilometer.api import hooks
 from ceilometer.api import middleware
 from ceilometer import service
+from ceilometer import storage
 from ceilometer.openstack.common import log
 from wsgiref import simple_server
 
@@ -51,9 +52,13 @@ def get_pecan_config():
 
 
 def setup_app(pecan_config=None, extra_hooks=None):
+    storage_engine = storage.get_engine(cfg.CONF)
     # FIXME: Replace DBHook with a hooks.TransactionHook
     app_hooks = [hooks.ConfigHook(),
-                 hooks.DBHook(),
+                 hooks.DBHook(
+                     storage_engine,
+                     storage_engine.get_connection(cfg.CONF),
+                 ),
                  hooks.PipelineHook()]
     if extra_hooks:
         app_hooks.extend(extra_hooks)

ceilometer/api/hooks.py

@@ -21,7 +21,6 @@ from oslo.config import cfg
 from pecan import hooks
 
 from ceilometer import pipeline
-from ceilometer import storage
 from ceilometer import transformer
 
 
@@ -36,15 +35,13 @@ class ConfigHook(hooks.PecanHook):
 
 class DBHook(hooks.PecanHook):
 
-    def before(self, state):
-        storage_engine = storage.get_engine(state.request.cfg)
-        state.request.storage_engine = storage_engine
-        state.request.storage_conn = storage_engine.get_connection(
-            state.request.cfg)
+    def __init__(self, storage_engine, storage_connection):
+        self.storage_engine = storage_engine
+        self.storage_connection = storage_connection
 
-    # def after(self, state):
-    #     print 'method:', state.request.method
-    #     print 'response:', state.response.status
+    def before(self, state):
+        state.request.storage_engine = self.storage_engine
+        state.request.storage_conn = self.storage_connection
 
 
 class PipelineHook(hooks.PecanHook):