Revert "Remove unused add_network_to_project() method"

This reverts commit d8e39cb775a872c46d067bee8febc40dee799369.

Change-Id: I22f0692814ff029b4960ab32cbee63bbf4922106

5 files changed, 32 insertions, 5 deletions

diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 2993aaaf3..a55e7ab80 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -1995,12 +1995,20 @@ def key_pair_count_by_user(context, user_id):
 
 
 @require_admin_context
-def network_associate(context, project_id):
+def network_associate(context, project_id, force=False):
     """Associate a project with a network.
 
     called by project_get_networks under certain conditions
+    and network manager add_network_to_project()
 
     only associate if the project doesn't already have a network
+    or if force is True
+
+    force solves race condition where a fresh project has multiple instance
+    builds simultaneously picked up by multiple network hosts which attempt
+    to associate the project with multiple networks
+    force should only be used as a direct consequence of user request
+    all automated requests should not use force
     """
     session = get_session()
     with session.begin():
@@ -2012,10 +2020,13 @@ def network_associate(context, project_id):
                            with_lockmode('update').\
                            first()
 
-        # find out if project has a network
-        network_ref = network_query(project_id)
-        if not network_ref:
-            # project doesn't have a network so associate with a new network
+        if not force:
+            # find out if project has a network
+            network_ref = network_query(project_id)
+
+        if force or not network_ref:
+            # in force mode or project doesn't have a network so associate
+            # with a new network
 
             # get new network
             network_ref = network_query(None)
diff --git a/nova/network/api.py b/nova/network/api.py
index d2c311f95..ae230455f 100644
--- a/nova/network/api.py
+++ b/nova/network/api.py
@@ -278,6 +278,12 @@ class API(base.Base):
                  {'method': 'remove_fixed_ip_from_instance',
                   'args': args})
 
+    def add_network_to_project(self, context, project_id):
+        """Force adds another network to a project."""
+        rpc.call(context, FLAGS.network_topic,
+                 {'method': 'add_network_to_project',
+                  'args': {'project_id': project_id}})
+
     @refresh_cache
     def get_instance_nw_info(self, context, instance):
         """Returns all network info related to an instance."""
diff --git a/nova/network/manager.py b/nova/network/manager.py
index f81004fed..116413007 100644
--- a/nova/network/manager.py
+++ b/nova/network/manager.py
@@ -1906,6 +1906,11 @@ class VlanManager(RPCAllocateFixedIP, FloatingIP, NetworkManager):
         self._setup_network_on_host(context, network)
         return address
 
+    @wrap_check_policy
+    def add_network_to_project(self, context, project_id):
+        """Force adds another network to a project."""
+        self.db.network_associate(context, project_id, force=True)
+
     def _get_networks_for_instance(self, context, instance_id, project_id,
                                    requested_networks=None):
         """Determine which networks an instance should connect to."""
diff --git a/nova/network/quantumv2/api.py b/nova/network/quantumv2/api.py
index 16dba96fa..50042278b 100644
--- a/nova/network/quantumv2/api.py
+++ b/nova/network/quantumv2/api.py
@@ -244,6 +244,10 @@ class API(base.Base):
         it is associated with."""
         raise NotImplementedError()
 
+    def add_network_to_project(self, context, project_id):
+        """Force add a network to the project."""
+        raise NotImplementedError()
+
     def _build_network_info_model(self, context, instance, networks=None):
         search_opts = {'tenant_id': instance['project_id'],
                        'device_id': instance['uuid'], }
diff --git a/nova/tests/policy.json b/nova/tests/policy.json
index 4836a33b4..c2388d411 100644
--- a/nova/tests/policy.json
+++ b/nova/tests/policy.json
@@ -170,6 +170,7 @@
     "network:get_fixed_ip": [],
     "network:add_fixed_ip_to_instance": [],
     "network:remove_fixed_ip_from_instance": [],
+    "network:add_network_to_project": [],
     "network:get_instance_nw_info": [],
 
     "network:get_dns_domains": [],