[cloud] ec2_vpc_route_table: ignore routes without DestinationCidrBlock - fixes #37003 (#37010)

* [cloud] ec2_vpc_route_table: ignore routes without DestinationCidrBlock

Add module warnings rather than silently skipping

* Permit warnings for routes tables containing vpc endpoints to be turned off

* Add tests to ensure a VPC endpoint associated with a route table does not result in a traceback

lib/ansible/modules/cloud/amazon/ec2_vpc_route_table.py

@@ -413,12 +413,15 @@ def get_route_table_by_tags(connection, module, vpc_id, tags):
 def route_spec_matches_route(route_spec, route):
     if route_spec.get('GatewayId') and 'nat-' in route_spec['GatewayId']:
         route_spec['NatGatewayId'] = route_spec.pop('GatewayId')
+    if route_spec.get('GatewayId') and 'vpce-' in route_spec['GatewayId']:
+        if route_spec.get('DestinationCidrBlock', '').startswith('pl-'):
+            route_spec['DestinationPrefixListId'] = route_spec.pop('DestinationCidrBlock')
 
     return set(route_spec.items()).issubset(route.items())
 
 
 def route_spec_matches_route_cidr(route_spec, route):
-    return route_spec['DestinationCidrBlock'] == route['DestinationCidrBlock']
+    return route_spec['DestinationCidrBlock'] == route.get('DestinationCidrBlock')
 
 
 def rename_key(d, old_key, new_key):
@@ -441,15 +444,26 @@ def ensure_routes(connection=None, module=None, route_table=None, route_specs=No
     for route_spec in route_specs:
         match = index_of_matching_route(route_spec, routes_to_match)
         if match is None:
+            if route_spec.get('DestinationCidrBlock'):
                 route_specs_to_create.append(route_spec)
+            else:
+                module.warn("Skipping creating {0} because it has no destination cidr block. "
+                            "To add VPC endpoints to route tables use the ec2_vpc_endpoint module.".format(route_spec))
         else:
             if match[0] == "replace":
+                if route_spec.get('DestinationCidrBlock'):
                     route_specs_to_recreate.append(route_spec)
+                else:
+                    module.warn("Skipping recreating route {0} because it has no destination cidr block.".format(route_spec))
             del routes_to_match[match[1]]
 
     routes_to_delete = []
     if purge_routes:
         for r in routes_to_match:
+            if not r.get('DestinationCidrBlock'):
+                module.warn("Skipping purging route {0} because it has no destination cidr block. "
+                            "To remove VPC endpoints from route tables use the ec2_vpc_endpoint module.".format(r))
+                continue
             if r['Origin'] == 'CreateRoute':
                 routes_to_delete.append(r)
 

test/integration/targets/ec2_vpc_route_table/tasks/main.yml

@@ -545,10 +545,55 @@
         - recreate_private_table.changed
         - recreate_private_table.route_table.id != create_public_table.route_table.id
 
+  - name: create a VPC endpoint to test ec2_vpc_route_table ignores it
+    ec2_vpc_endpoint:
+      state: present
+      vpc_id: "{{ vpc.vpc.id }}"
+      service: "com.amazonaws.{{ aws_region }}.s3"
+      route_table_ids:
+        - "{{ recreate_private_table.route_table.route_table_id }}"
+      <<: *aws_connection_info
+    register: vpc_endpoint
+
+  - name: purge routes
+    ec2_vpc_route_table:
+      vpc_id: "{{ vpc.vpc.id }}"
+      tags:
+        Public: "false"
+        Name: "Private route table"
+      routes:
+      - nat_gateway_id: "{{ nat_gateway.nat_gateway_id }}"
+        dest: 0.0.0.0/0
+      subnets: "{{ vpc_subnets|json_query('subnets[?tags.Public == `False`].id') }}"
+      purge_routes: true
+      <<: *aws_connection_info
+    register: result
+
+  - name: Get endpoint facts to verify that it wasn't purged from the route table
+    ec2_vpc_endpoint_facts:
+      query: endpoints
+      vpc_endpoint_ids:
+        - "{{ vpc_endpoint.result.vpc_endpoint_id }}"
+      <<: *aws_connection_info
+    register: endpoint_details
+
+  - name: assert the route table is associated with the VPC endpoint
+    assert:
+      that:
+        - endpoint_details.vpc_endpoints[0].route_table_ids[0] == recreate_private_table.route_table.route_table_id
+
   always:
   #############################################################################
   # TEAR DOWN STARTS HERE
   #############################################################################
+  - name: remove the VPC endpoint
+    ec2_vpc_endpoint:
+      state: absent
+      vpc_endpoint_id: "{{ vpc_endpoint.result.vpc_endpoint_id }}"
+      <<: *aws_connection_info
+    when: vpc_endpoint is defined
+    ignore_errors: yes
+
   - name: destroy route tables
     ec2_vpc_route_table:
       route_table_id: "{{ item.route_table.id }}"