Isolate backend loading

Pecan uses thread local storage and so if we combine pecan and eventlet
we need to make sure that eventlet is monkey patched before pecan is
first loaded.

To keep the paste.ini file untouched we need to keep the app creation in
service.py but we can't load that from keystone-all because it has pecan
in it.

So we create a new file that can be safely imported before pecan is
loaded.

Change-Id: If7abf1db9859d66c06f7f223056c106292f256fa
blueprint: keystone-pecan

bin/keystone-all

@@ -41,6 +41,7 @@ from keystone.openstack.common import gettextutils
 # gettextutils._() is called at import time.
 gettextutils.enable_lazy()
 
+from keystone import backends
 from keystone.common import dependency
 from keystone.common import environment
 from keystone.common import sql
@@ -48,7 +49,6 @@ from keystone.common import utils
 from keystone import config
 from keystone.openstack.common.gettextutils import _
 from keystone.openstack.common import importutils
-from keystone import service
 
 
 CONF = config.CONF
@@ -131,7 +131,7 @@ if __name__ == '__main__':
         monkeypatch_thread = False
     environment.use_eventlet(monkeypatch_thread)
 
-    service.load_backends()
+    backends.load_backends()
 
     servers = []
     servers.append(create_server(paste_config,

httpd/keystone.py

@@ -24,12 +24,12 @@ from keystone.openstack.common import gettextutils
 # gettextutils._() is called at import time.
 gettextutils.enable_lazy()
 
+from keystone import backends
 from keystone.common import dependency
 from keystone.common import environment
 from keystone.common import sql
 from keystone import config
 from keystone.openstack.common import log
-from keystone import service
 
 
 CONF = config.CONF
@@ -48,7 +48,7 @@ if CONF.debug:
     CONF.log_opt_values(log.getLogger(CONF.prog), logging.DEBUG)
 
 
-drivers = service.load_backends()
+drivers = backends.load_backends()
 
 # NOTE(ldbragst): 'application' is required in this context by WSGI spec.
 # The following is a reference to Python Paste Deploy documentation

keystone/backends.py

@@ -0,0 +1,48 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from keystone import assignment
+from keystone import auth
+from keystone import catalog
+from keystone.common import cache
+from keystone.contrib import endpoint_filter
+from keystone import credential
+from keystone import identity
+from keystone import policy
+from keystone import token
+from keystone import trust
+
+
+def load_backends():
+
+    # Configure and build the cache
+    cache.configure_cache_region(cache.REGION)
+
+    # Ensure that the identity driver is created before the assignment manager.
+    # The default assignment driver is determined by the identity driver, so
+    # the identity driver must be available to the assignment manager.
+    _IDENTITY_API = identity.Manager()
+
+    DRIVERS = dict(
+        assignment_api=assignment.Manager(),
+        catalog_api=catalog.Manager(),
+        credential_api=credential.Manager(),
+        endpoint_filter_api=endpoint_filter.Manager(),
+        identity_api=_IDENTITY_API,
+        policy_api=policy.Manager(),
+        token_api=token.Manager(),
+        trust_api=trust.Manager(),
+        token_provider_api=token.provider.Manager())
+
+    auth.controllers.load_auth_methods()
+
+    return DRIVERS

keystone/service.py

@@ -20,10 +20,8 @@ import routes
 from keystone import assignment
 from keystone import auth
 from keystone import catalog
-from keystone.common import cache
 from keystone.common import wsgi
 from keystone import config
-from keystone.contrib import endpoint_filter
 from keystone import controllers
 from keystone import credential
 from keystone import identity
@@ -38,32 +36,6 @@ CONF = config.CONF
 LOG = log.getLogger(__name__)
 
 
-def load_backends():
-
-    # Configure and build the cache
-    cache.configure_cache_region(cache.REGION)
-
-    # Ensure that the identity driver is created before the assignment manager.
-    # The default assignment driver is determined by the identity driver, so
-    # the identity driver must be available to the assignment manager.
-    _IDENTITY_API = identity.Manager()
-
-    DRIVERS = dict(
-        assignment_api=assignment.Manager(),
-        catalog_api=catalog.Manager(),
-        credential_api=credential.Manager(),
-        endpoint_filter_api=endpoint_filter.Manager(),
-        identity_api=_IDENTITY_API,
-        policy_api=policy.Manager(),
-        token_api=token.Manager(),
-        trust_api=trust.Manager(),
-        token_provider_api=token.provider.Manager())
-
-    auth.controllers.load_auth_methods()
-
-    return DRIVERS
-
-
 def fail_gracefully(f):
     """Logs exceptions and aborts."""
     @functools.wraps(f)

keystone/tests/core.py

@@ -42,6 +42,7 @@ from keystone.common import environment
 environment.use_eventlet()
 
 from keystone import auth
+from keystone import backends
 from keystone.common import dependency
 from keystone.common import kvs
 from keystone.common.kvs import core as kvs_core
@@ -52,7 +53,6 @@ from keystone import notifications
 from keystone.openstack.common.fixture import config as config_fixture
 from keystone.openstack.common.gettextutils import _
 from keystone.openstack.common import log
-from keystone import service
 from keystone.tests import ksfixtures
 
 # NOTE(dstanek): Tests inheriting from TestCase depend on having the
@@ -436,7 +436,7 @@ class TestCase(BaseTestCase):
         kvs_core.KEY_VALUE_STORE_REGISTRY.clear()
 
         self.clear_auth_plugin_registry()
-        drivers = service.load_backends()
+        drivers = backends.load_backends()
 
         drivers.update(dependency.resolve_future_dependencies())