Associate floating IP with router interface

This change will create a dependency from a FloatingIP to a RouterInterface in
this template which interfaces with the same subnet that this FloatingIP's
port is assigned to.

It would be preferable to add the dependency based on matching FloatingIP
floating_network_id and Router external_gateway_info network, but there is
a valid use-case for the Router being external to the template, so the
dependency is matched on the internal subnet instead, which is available
from the RouterInterface property.

Change-Id: Iedff00b382b4fcda741ca5c9b4adc23b176ec48c
Closes-Bug: #1299259

2 files changed, 46 insertions, 2 deletions

diff --git a/heat/engine/resources/neutron/floatingip.py b/heat/engine/resources/neutron/floatingip.py
index f3a22f1c4..a374103b6 100644
--- a/heat/engine/resources/neutron/floatingip.py
+++ b/heat/engine/resources/neutron/floatingip.py
@@ -14,6 +14,7 @@
 from heat.engine import attributes
 from heat.engine import properties
 from heat.engine.resources.neutron import neutron
+from heat.engine.resources.neutron import port
 from heat.engine.resources.neutron import router
 from heat.engine import support
 
@@ -93,9 +94,10 @@ class FloatingIP(neutron.NeutronResource):
 
     def add_dependencies(self, deps):
         super(FloatingIP, self).add_dependencies(deps)
-        # depend on any RouterGateway in this template with the same
-        # network_id as this floating_network_id
+
         for resource in self.stack.itervalues():
+            # depend on any RouterGateway in this template with the same
+            # network_id as this floating_network_id
             if resource.has_interface('OS::Neutron::RouterGateway'):
                 gateway_network = resource.properties.get(
                     router.RouterGateway.NETWORK) or resource.properties.get(
@@ -106,6 +108,31 @@ class FloatingIP(neutron.NeutronResource):
                 if gateway_network == floating_network:
                     deps += (self, resource)
 
+            # depend on any RouterInterface in this template which interfaces
+            # with the same subnet that this floating IP's port is assigned
+            # to
+            elif resource.has_interface('OS::Neutron::RouterInterface'):
+
+                def port_on_subnet(resource, subnet):
+                    if not resource.has_interface('OS::Neutron::Port'):
+                        return False
+                    for fixed_ip in resource.properties.get(
+                            port.Port.FIXED_IPS):
+
+                        port_subnet = (
+                            fixed_ip.properties.get(port.Port.FIXED_IP_SUBNET)
+                            or fixed_ip.get(port.Port.FIXED_IP_SUBNET_ID))
+                        return subnet == port_subnet
+                    return False
+
+                interface_subnet = (
+                    resource.properties.get(router.RouterInterface.SUBNET) or
+                    resource.properties.get(router.RouterInterface.SUBNET_ID))
+                for d in deps.required_by(self):
+                    if port_on_subnet(d, interface_subnet):
+                        deps += (self, resource)
+                        break
+
     def validate(self):
         super(FloatingIP, self).validate()
         self._validate_depr_property_required(
diff --git a/heat/tests/test_neutron.py b/heat/tests/test_neutron.py
index 53235c69a..194aa6c96 100644
--- a/heat/tests/test_neutron.py
+++ b/heat/tests/test_neutron.py
@@ -269,6 +269,13 @@ neutron_floating_template_deprecated = '''
     "router": {
       "Type": "OS::Neutron::Router"
     },
+    "router_interface": {
+      "Type": "OS::Neutron::RouterInterface",
+      "Properties": {
+        "router_id": { "Ref" : "router" },
+        "subnet": "sub1234"
+      }
+    },
     "gateway": {
       "Type": "OS::Neutron::RouterGateway",
       "Properties": {
@@ -312,6 +319,13 @@ neutron_floating_template = '''
     "router": {
       "Type": "OS::Neutron::Router"
     },
+    "router_interface": {
+      "Type": "OS::Neutron::RouterInterface",
+      "Properties": {
+        "router_id": { "Ref" : "router" },
+        "subnet": "sub1234"
+      }
+    },
     "gateway": {
       "Type": "OS::Neutron::RouterGateway",
       "Properties": {
@@ -1927,6 +1941,9 @@ class NeutronFloatingIPTest(HeatTestCase):
 
         self.assertIn(stack['floating_ip'], deps)
 
+        deps = stack.dependencies[stack['router_interface']]
+        self.assertIn(stack['floating_ip'], deps)
+
         fip = stack['floating_ip']
         scheduler.TaskRunner(fip.create)()
         self.assertEqual((fip.CREATE, fip.COMPLETE), fip.state)