Improve doc to show support for IPv6 CIDR block (#634) (#751)

[PR #634/c06d77c9 backport][stable-3] Improve doc to show support for IPv6 CIDR block

This is a backport of PR #634 as merged into main (c06d77c).
SUMMARY


Improve doc to show IPv6 CIDR blocks are supported.
Add example with IPv6 CIDR block.
Add missing attribute to return values.
Remove duplicate assertions in integration tests.
Add tests for IPv6 subnets in integration tests.


ISSUE TYPE


Bugfix Pull Request

COMPONENT NAME

ec2_vpc_route_table
ADDITIONAL INFORMATION



While testing IPv6 in this module, I discovered the ipsubnet filter does not work if the prefix length has a fairly high value such as /120.

I was running an integration test with a /120 subnet in this PR, but the ipsubnet call never returns and uses 100% CPU. I changed the value to a /64 subnet so this PR can pass.
The ipsubnet issue needs to be fixed in ansible.netcommon and the netaddr package. I've created a unit test to reproduce the problem: ansible-collections/ansible.netcommon#362


The integration tests in this PR depend on #631 for the VPC configuration.

plugins/modules/ec2_vpc_route_table.py

@@ -48,18 +48,13 @@
     type: str
   routes:
     description:
-        - >
-          List of routes in the route table.
-        - >
-          Routes are specified as dicts containing the keys 'dest' and one of 'gateway_id',
-          'instance_id', 'network_interface_id', or 'vpc_peering_connection_id'.
-        - >
-          The value of 'dest' is used for the destination match. It may be a IPv4 CIDR block
+        - List of routes in the route table.
+        - Routes are specified as dicts containing the keys C(dest) and one of C(gateway_id),
+          C(instance_id), C(network_interface_id), or C(vpc_peering_connection_id).
+        - The value of C(dest) is used for the destination match. It may be a IPv4 CIDR block
           or a IPv6 CIDR block.
-        - >
-          If 'gateway_id' is specified, you can refer to the VPC's IGW by using the value 'igw'.
-        - >
-          Routes are required for present states.
+        - If I(gateway_id) is specified, you can refer to the VPC's IGW by using the value C(igw).
+        - Routes are required for present states.
     type: list
     elements: dict
   state:

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

@@ -514,7 +514,7 @@
       lookup: id
       purge_tags: yes
       tags:
-        Name: Public routeroute_spec table
+        Name: Public route table
         Updated: new_tag
     check_mode: true
     register: check_mode_results