Remove unused bridge interfaces

If a network gateway of multi hosted network is unsed by any VM on the
host, we tear down it.
It is implemented only with the VLAN manager.

Fixes LP bug #1084651

Change-Id: Ia7e399de5b8ddf6ec252d38dfbb8762c4f14e3a5

2 files changed, 9 insertions, 0 deletions

diff --git a/nova/db/api.py b/nova/db/api.py
index cfa6a6487..67d8e7618 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -809,6 +809,10 @@ def network_get_all_by_uuids(context, network_uuids,
 
 # pylint: disable=C0103
 
+def network_in_use_on_host(context, network_id, host=None):
+    """Indicates if a network is currently in use on host."""
+    return IMPL.network_in_use_on_host(context, network_id, host)
+
 
 def network_get_associated_fixed_ips(context, network_id, host=None):
     """Get all network's ips that have been associated."""
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 4155fdc3d..e1e2ede84 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -2236,6 +2236,11 @@ def network_get_associated_fixed_ips(context, network_id, host=None):
     return data
 
 
+def network_in_use_on_host(context, network_id, host):
+    fixed_ips = network_get_associated_fixed_ips(context, network_id, host)
+    return len(fixed_ips) > 0
+
+
 @require_admin_context
 def _network_get_query(context, session=None):
     return model_query(context, models.Network, session=session,