Stops compute api import at import time

There is an automatic import of compute.api at import time
whenever anything under compute is imported. This leads to all
sorts of weird dependency problems such as the one here:
https://review.openstack.org/#/c/14170/

This modifies the import to happen when compute.API() is called,
which is how we handle it for network and volume. A few imports
were also modified to make it consistent with this new style.

Change-Id: Ic748376510aa4cc48dfefc6ec36621d0ae498bfc

5 files changed, 17 insertions, 11 deletions

diff --git a/nova/api/ec2/cloud.py b/nova/api/ec2/cloud.py
index aa7e880df..7bba05f3b 100644
--- a/nova/api/ec2/cloud.py
+++ b/nova/api/ec2/cloud.py
@@ -30,6 +30,7 @@ from nova.api.ec2 import inst_state
 from nova.api import validator
 from nova import block_device
 from nova import compute
+from nova.compute import api as compute_api
 from nova.compute import instance_types
 from nova.compute import vm_states
 from nova import db
@@ -187,7 +188,7 @@ class CloudController(object):
         self.compute_api = compute.API(network_api=self.network_api,
                                    volume_api=self.volume_api,
                                    security_group_api=self.security_group_api)
-        self.keypair_api = compute.api.KeypairAPI()
+        self.keypair_api = compute_api.KeypairAPI()
 
     def __str__(self):
         return 'CloudController'
@@ -1580,7 +1581,7 @@ class CloudController(object):
         return {'imageId': ec2_id}
 
 
-class CloudSecurityGroupAPI(compute.api.SecurityGroupAPI):
+class CloudSecurityGroupAPI(compute_api.SecurityGroupAPI):
     @staticmethod
     def raise_invalid_property(msg):
         raise exception.InvalidParameterValue(err=msg)
diff --git a/nova/api/openstack/compute/contrib/security_groups.py b/nova/api/openstack/compute/contrib/security_groups.py
index e5b1797b4..ee36ee58d 100644
--- a/nova/api/openstack/compute/contrib/security_groups.py
+++ b/nova/api/openstack/compute/contrib/security_groups.py
@@ -26,6 +26,7 @@ from nova.api.openstack import extensions
 from nova.api.openstack import wsgi
 from nova.api.openstack import xmlutil
 from nova import compute
+from nova.compute import api as compute_api
 from nova import db
 from nova import exception
 from nova import flags
@@ -558,7 +559,7 @@ class Security_groups(extensions.ExtensionDescriptor):
         return resources
 
 
-class NativeSecurityGroupAPI(compute.api.SecurityGroupAPI):
+class NativeSecurityGroupAPI(compute_api.SecurityGroupAPI):
     @staticmethod
     def raise_invalid_property(msg):
         raise exc.HTTPBadRequest(explanation=msg)
diff --git a/nova/compute/__init__.py b/nova/compute/__init__.py
index 2916ff048..b770778aa 100644
--- a/nova/compute/__init__.py
+++ b/nova/compute/__init__.py
@@ -21,5 +21,8 @@
 import nova.flags
 import nova.openstack.common.importutils
 
-API = nova.openstack.common.importutils.import_class(
-        nova.flags.FLAGS.compute_api_class)
+
+def API(*args, **kwargs):
+    importutils = nova.openstack.common.importutils
+    cls = importutils.import_class(nova.flags.FLAGS.compute_api_class)
+    return cls(*args, **kwargs)
diff --git a/nova/tests/api/openstack/fakes.py b/nova/tests/api/openstack/fakes.py
index bb6542c16..dc83447e4 100644
--- a/nova/tests/api/openstack/fakes.py
+++ b/nova/tests/api/openstack/fakes.py
@@ -32,6 +32,7 @@ from nova.api.openstack.compute import versions
 from nova.api.openstack import urlmap
 from nova.api.openstack import volume
 from nova.api.openstack import wsgi as os_wsgi
+from nova.compute import api as compute_api
 from nova.compute import instance_types
 from nova.compute import vm_states
 from nova import context
@@ -160,7 +161,7 @@ def stub_out_compute_api_snapshot(stubs):
         return dict(id='123', status='ACTIVE', name=name,
                     properties=extra_properties)
 
-    stubs.Set(nova.compute.API, 'snapshot', snapshot)
+    stubs.Set(compute_api.API, 'snapshot', snapshot)
 
 
 class stub_out_compute_api_backup(object):
@@ -168,7 +169,7 @@ class stub_out_compute_api_backup(object):
     def __init__(self, stubs):
         self.stubs = stubs
         self.extra_props_last_call = None
-        stubs.Set(nova.compute.API, 'backup', self.backup)
+        stubs.Set(compute_api.API, 'backup', self.backup)
 
     def backup(self, context, instance, name, backup_type, rotation,
                extra_properties=None):
diff --git a/nova/tests/compute/test_compute.py b/nova/tests/compute/test_compute.py
index cad27b544..cf81c699d 100644
--- a/nova/tests/compute/test_compute.py
+++ b/nova/tests/compute/test_compute.py
@@ -218,7 +218,7 @@ class ComputeTestCase(BaseTestCase):
         self.stubs.Set(compute_utils, 'add_instance_fault_from_exc',
                        did_it_add_fault)
 
-        @nova.compute.manager.wrap_instance_fault
+        @compute_manager.wrap_instance_fault
         def failer(self2, context, instance):
             raise NotImplementedError()
 
@@ -238,7 +238,7 @@ class ComputeTestCase(BaseTestCase):
         self.stubs.Set(compute_utils, 'add_instance_fault_from_exc',
                        did_it_add_fault)
 
-        @nova.compute.manager.wrap_instance_fault
+        @compute_manager.wrap_instance_fault
         def failer(self2, context, instance_uuid):
             raise exception.InstanceNotFound()
 
@@ -2667,7 +2667,7 @@ class ComputeAPITestCase(BaseTestCase):
         super(ComputeAPITestCase, self).setUp()
         self.stubs.Set(network_api.API, 'get_instance_nw_info',
                        fake_get_nw_info)
-        self.security_group_api = compute.api.SecurityGroupAPI()
+        self.security_group_api = compute_api.SecurityGroupAPI()
         self.compute_api = compute.API(
                                    security_group_api=self.security_group_api)
         self.fake_image = {
@@ -4916,7 +4916,7 @@ class ComputePolicyTestCase(BaseTestCase):
         self.mox.StubOutWithMock(nova.policy, 'enforce')
         nova.policy.enforce(self.context, 'compute:reboot', {})
         self.mox.ReplayAll()
-        nova.compute.api.check_policy(self.context, 'reboot', {})
+        compute_api.check_policy(self.context, 'reboot', {})
 
     def test_wrapped_method(self):
         instance = self._create_fake_instance(params={'host': None})