Don't query nova-network on startup.

Fix bug 999698.

nova-compute requested network info for each instance on startup via rpc.
If all services get (re)started at the same time, nova-network may not
be available to take this request, resulting in a lost request.  To
combat this issue, get the network info from the cache in the database
on startup.  If by some chance this information is not correct, it will
get fixed up by a periodic task.

Change-Id: I0bbd475e078ac2a67c99c2be4711e86d617c609a

nova/api/openstack/common.py

@@ -26,11 +26,11 @@
 from nova.api.openstack import wsgi
 from nova.api.openstack import xmlutil
 from nova.compute import task_states
+from nova.compute import utils as compute_utils
 from nova.compute import vm_states
 from nova import exception
 from nova import flags
 from nova import log as logging
-from nova.network import model as network_model
 from nova import quota
 
 
@@ -321,12 +321,6 @@ def get_networks_for_instance_from_nw_info(nw_info):
     return networks
 
 
-def get_nw_info_for_instance(context, instance):
-    info_cache = instance['info_cache'] or {}
-    cached_nwinfo = info_cache.get('network_info') or []
-    return network_model.NetworkInfo.hydrate(cached_nwinfo)
-
-
 def get_networks_for_instance(context, instance):
     """Returns a prepared nw_info list for passing into the view builders
 
@@ -338,7 +332,7 @@ def get_networks_for_instance(context, instance):
                                      {'addr': '172.16.2.1', 'version': 4}]},
          ...}
     """
-    nw_info = get_nw_info_for_instance(context, instance)
+    nw_info = compute_utils.get_nw_info_for_instance(instance)
     return get_networks_for_instance_from_nw_info(nw_info)
 
 

nova/api/openstack/compute/contrib/cloudpipe.py

@@ -16,13 +16,13 @@
 
 import os
 
-from nova.api.openstack import common
 from nova.api.openstack import extensions
 from nova.api.openstack import wsgi
 from nova.api.openstack import xmlutil
 from nova.auth import manager
 from nova.cloudpipe import pipelib
 from nova import compute
+from nova.compute import utils as compute_utils
 from nova.compute import vm_states
 from nova import db
 from nova import exception
@@ -91,7 +91,7 @@ def _vpn_dict(self, context, project_id, instance):
             return rv
         rv['instance_id'] = instance['uuid']
         rv['created_at'] = utils.isotime(instance['created_at'])
-        nw_info = common.get_nw_info_for_instance(elevated, instance)
+        nw_info = compute_utils.get_nw_info_for_instance(instance)
         if not nw_info:
             return rv
         vif = nw_info[0]

nova/compute/manager.py

@@ -287,7 +287,7 @@ def init_host(self):
             LOG.debug(_('Current state is %(drv_state)s, state in DB is '
                         '%(db_state)s.'), locals(), instance=instance)
 
-            net_info = self._get_instance_nw_info(context, instance)
+            net_info = compute_utils.get_nw_info_for_instance(instance)
             if ((expect_running and FLAGS.resume_guests_state_on_host_boot) or
                 FLAGS.start_guests_on_host_boot):
                 LOG.info(_('Rebooting instance after nova-compute restart.'),

nova/compute/utils.py

@@ -19,6 +19,7 @@
 from nova import db
 from nova import flags
 from nova import log
+from nova.network import model as network_model
 from nova import notifications
 from nova.notifier import api as notifier_api
 
@@ -100,3 +101,9 @@ def notify_about_instance_usage(context, instance, event_suffix,
     notifier_api.notify(context, 'compute.%s' % host,
                         'compute.instance.%s' % event_suffix,
                         notifier_api.INFO, usage_info)
+
+
+def get_nw_info_for_instance(instance):
+    info_cache = instance['info_cache'] or {}
+    cached_nwinfo = info_cache.get('network_info') or []
+    return network_model.NetworkInfo.hydrate(cached_nwinfo)

nova/tests/api/openstack/compute/contrib/test_cloudpipe.py

@@ -15,9 +15,9 @@
 
 from lxml import etree
 
-from nova.api.openstack import common
 from nova.api.openstack.compute.contrib import cloudpipe
 from nova.api.openstack import wsgi
+from nova.compute import utils as compute_utils
 from nova import db
 from nova import flags
 from nova import test
@@ -65,11 +65,11 @@ def setUp(self):
 
     def test_cloudpipe_list_no_network(self):
 
-        def common_get_nw_info_for_instance(context, instance):
+        def fake_get_nw_info_for_instance(instance):
             return {}
 
-        self.stubs.Set(common, "get_nw_info_for_instance",
-                       common_get_nw_info_for_instance)
+        self.stubs.Set(compute_utils, "get_nw_info_for_instance",
+                       fake_get_nw_info_for_instance)
         self.stubs.Set(self.controller.compute_api, "get_all",
                        compute_api_get_all)
         req = fakes.HTTPRequest.blank('/v2/fake/os-cloudpipe')
@@ -86,12 +86,12 @@ def network_api_get(context, network_id):
             return {'vpn_public_address': '127.0.0.1',
                     'vpn_public_port': 22}
 
-        def common_get_nw_info_for_instance(context, instance):
+        def fake_get_nw_info_for_instance(instance):
             return fake_network.fake_get_instance_nw_info(self.stubs,
                                                           spectacular=True)
 
-        self.stubs.Set(common, "get_nw_info_for_instance",
-                       common_get_nw_info_for_instance)
+        self.stubs.Set(compute_utils, "get_nw_info_for_instance",
+                       fake_get_nw_info_for_instance)
         self.stubs.Set(self.controller.network_api, "get",
                        network_api_get)
         self.stubs.Set(self.controller.compute_api, "get_all",