Add segments attribute to OS::Neutron::Net

Adds a attribute to the neutron Net resource to get the
segments of a network.

Story: 2001988
Task: 19610
Change-Id: I7acb3d29a01fa92bebdb2c85094655e27cb16a29

heat/engine/resources/openstack/neutron/net.py

@@ -42,10 +42,12 @@ class Net(neutron.NeutronResource):
 
     ATTRIBUTES = (
         STATUS, NAME_ATTR, SUBNETS, ADMIN_STATE_UP_ATTR, TENANT_ID_ATTR,
-        PORT_SECURITY_ENABLED_ATTR, MTU_ATTR, QOS_POLICY_ATTR, L2_ADJACENCY
+        PORT_SECURITY_ENABLED_ATTR, MTU_ATTR, QOS_POLICY_ATTR, L2_ADJACENCY,
+        SEGMENTS,
     ) = (
         "status", "name", "subnets", "admin_state_up", "tenant_id",
-        "port_security_enabled", "mtu", 'qos_policy_id', 'l2_adjacency'
+        "port_security_enabled", "mtu", 'qos_policy_id', 'l2_adjacency',
+        'segments',
     )
 
     properties_schema = {
@@ -167,6 +169,11 @@ class Net(neutron.NeutronResource):
             type=attributes.Schema.BOOLEAN,
             support_status=support.SupportStatus(version='9.0.0'),
         ),
+        SEGMENTS: attributes.Schema(
+            _("The segments of this network."),
+            type=attributes.Schema.LIST,
+            support_status=support.SupportStatus(version='11.0.0'),
+        ),
     }
 
     def translation_rules(self, properties):
@@ -273,6 +280,15 @@ class Net(neutron.NeutronResource):
             pass
         return result
 
+    def _resolve_attribute(self, name):
+        if self.resource_id is None:
+            return
+        if name == self.SEGMENTS:
+            return [segment.to_dict() for segment in list(self.client(
+                'openstack').network.segments(network_id=self.resource_id))]
+        attributes = self._show_resource()
+        return attributes[name]
+
 
 def resource_mapping():
     return {

heat/tests/openstack/neutron/test_neutron_net.py

@@ -27,7 +27,7 @@ from heat.tests import utils
 
 
 neutron_template = '''
-heat_template_version: 2015-04-30
+heat_template_version: rocky
 description: Template to test network Neutron resource
 resources:
   network:
@@ -288,7 +288,7 @@ class NeutronNetTest(common.HeatTestCase):
 
     def test_net_get_live_state(self):
         tmpl = """
-        heat_template_version: 2015-10-15
+        heat_template_version: rocky
         resources:
           net:
             type: OS::Neutron::Net

releasenotes/notes/network-attribute-segments-984ec5b3e75d657b.yaml

@@ -0,0 +1,14 @@
+---
+features:
+  - |
+    Adds a new attribute ``segments`` to the ``OS::Neutron::Net`` resource.
+    The attribute resolves the network segments on the network.  The attribute
+    is useful when migrating from a non routed provider network to a routed
+    provider network. The example below show how to migrate an existing subnet
+    to one that is associated with the segment::
+
+      TestSubnet:
+        type: OS::Neutron::Subnet
+        name: the_subnet
+        properties:
+          segment: {get_attr: [the_network, segments, 0, id]}