Remove cyclic import between rpcapi and objects.base

There was a cyclic import between conductor.rpcapi and objects.base,
this was initally fixed by doing an import at runtime. This patch fixes
the import cycle for good.

Change-Id: I8ee8c47652de75430312f77ddee08adc7a237d2b
Closes-Bug: #1623074

3 files changed, 46 insertions, 31 deletions

diff --git a/ironic/cmd/api.py b/ironic/cmd/api.py
index c205a1566..fe2a058eb 100644
--- a/ironic/cmd/api.py
+++ b/ironic/cmd/api.py
@@ -23,6 +23,7 @@ from oslo_config import cfg
 
 from ironic.common import service as ironic_service
 from ironic.objects import base
+from ironic.objects import indirection
 
 CONF = cfg.CONF
 
@@ -32,7 +33,8 @@ def main():
     ironic_service.prepare_service(sys.argv)
 
     # Enable object backporting via the conductor
-    base.IronicObject.indirection_api = base.IronicObjectIndirectionAPI()
+    base.IronicObject.indirection_api = (
+        indirection.IronicObjectIndirectionAPI())
 
     # Build and start the WSGI app
     launcher = ironic_service.process_launcher()
diff --git a/ironic/objects/base.py b/ironic/objects/base.py
index 61af72b10..84ac7ebc7 100644
--- a/ironic/objects/base.py
+++ b/ironic/objects/base.py
@@ -90,36 +90,6 @@ class IronicObject(object_base.VersionedObject):
         return obj
 
 
-class IronicObjectIndirectionAPI(object_base.VersionedObjectIndirectionAPI):
-    def __init__(self):
-        super(IronicObjectIndirectionAPI, self).__init__()
-        # FIXME(xek): importing here due to a cyclical import error
-        from ironic.conductor import rpcapi as conductor_api
-        self._conductor = conductor_api.ConductorAPI()
-
-    def object_action(self, context, objinst, objmethod, args, kwargs):
-        return self._conductor.object_action(context, objinst, objmethod,
-                                             args, kwargs)
-
-    def object_class_action(self, context, objname, objmethod, objver,
-                            args, kwargs):
-        # NOTE(xek): This method is implemented for compatibility with
-        # oslo.versionedobjects 0.10.0 and older. It will be replaced by
-        # object_class_action_versions.
-        versions = object_base.obj_tree_get_versions(objname)
-        return self.object_class_action_versions(
-            context, objname, objmethod, versions, args, kwargs)
-
-    def object_class_action_versions(self, context, objname, objmethod,
-                                     object_versions, args, kwargs):
-        return self._conductor.object_class_action_versions(
-            context, objname, objmethod, object_versions, args, kwargs)
-
-    def object_backport_versions(self, context, objinst, object_versions):
-        return self._conductor.object_backport_versions(context, objinst,
-                                                        object_versions)
-
-
 class IronicObjectSerializer(object_base.VersionedObjectSerializer):
     # Base class to use for object hydration
     OBJ_BASE_CLASS = IronicObject
diff --git a/ironic/objects/indirection.py b/ironic/objects/indirection.py
new file mode 100644
index 000000000..b306820c4
--- /dev/null
+++ b/ironic/objects/indirection.py
@@ -0,0 +1,43 @@
+#    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 oslo_versionedobjects import base as object_base
+
+from ironic.conductor import rpcapi as conductor_api
+
+
+class IronicObjectIndirectionAPI(object_base.VersionedObjectIndirectionAPI):
+    def __init__(self):
+        super(IronicObjectIndirectionAPI, self).__init__()
+        self._conductor = conductor_api.ConductorAPI()
+
+    def object_action(self, context, objinst, objmethod, args, kwargs):
+        return self._conductor.object_action(context, objinst, objmethod,
+                                             args, kwargs)
+
+    def object_class_action(self, context, objname, objmethod, objver,
+                            args, kwargs):
+        # NOTE(xek): This method is implemented for compatibility with
+        # oslo.versionedobjects 0.10.0 and older. It will be replaced by
+        # object_class_action_versions.
+        versions = object_base.obj_tree_get_versions(objname)
+        return self.object_class_action_versions(
+            context, objname, objmethod, versions, args, kwargs)
+
+    def object_class_action_versions(self, context, objname, objmethod,
+                                     object_versions, args, kwargs):
+        return self._conductor.object_class_action_versions(
+            context, objname, objmethod, object_versions, args, kwargs)
+
+    def object_backport_versions(self, context, objinst, object_versions):
+        return self._conductor.object_backport_versions(context, objinst,
+                                                        object_versions)