[cloud] Add IPv6 support for ec2_vpc_subnet module(#30444)

* Add integration test suite for ec2_vpc_subnet

* wrap boto3 connection in try/except

update module documentation and add RETURN docs

add IPv6 support to VPC subnet module

rename ipv6cidr to ipv6_cidr, use required_if for parameter testing, update some failure messages to be more descriptive

DryRun mode was removed from this function a while ago but exception handling was still checking for it, removed

add wait and timeout for subnet creation process

fixup the ipv6 cidr disassociation logic a bit per review

update RETURN values per review

added module parameter check

removed DryRun parameter from boto3 call since it would always be false here

fix subnet wait loop

add a purge_tags parameter, fix the ensure_tags function, update to use compare_aws_tags func

fix tags type error per review

remove **kwargs use in create_subnet function per review

* rebased on #31870, fixed merge conflicts, and updated error messages

* fixes to pass tests

* add test for failure on invalid ipv6 block and update tags test for purge_tags=true function

* fix pylint issue

* fix exception handling error when run with python3

* add ipv6 tests and fix module code

* Add permissions to hacking/aws_config/testing_policies/ec2-policy.json for adding IPv6 cidr blocks to VPC and subnets

* fix type in tests and update assert conditional to check entire returned value

* add AWS_SESSION_TOKEN into environment for aws cli commands to work in CI

* remove key and value options from call to boto3_tag_list_to_ansible_dict

* remove wait loop and use boto3 EC2 waiter

* remove unused register: result vars

* revert az argument default value to original setting default=None

hacking/aws_config/testing_policies/ec2-policy.json

@@ -10,6 +10,8 @@
                 "ec2:AllocateAddress",
                 "ec2:AssociateAddress",
                 "ec2:AssociateRouteTable",
+                "ec2:AssociateVpcCidrBlock",
+                "ec2:AssociateSubnetCidrBlock",
                 "ec2:CreateImage",
                 "ec2:AttachInternetGateway",
                 "ec2:CreateInternetGateway",

lib/ansible/modules/cloud/amazon/ec2_vpc_subnet.py

@@ -23,14 +23,21 @@ requirements: [ boto3 ]
 options:
   az:
     description:
-      - "The availability zone for the subnet. Only required when state=present."
+      - "The availability zone for the subnet."
     required: false
     default: null
   cidr:
     description:
-      - "The CIDR block for the subnet. E.g. 192.0.2.0/24. Only required when state=present."
+      - "The CIDR block for the subnet. E.g. 192.0.2.0/24."
     required: false
     default: null
+  ipv6_cidr:
+    description:
+      - "The IPv6 CIDR block for the subnet. The VPC must have a /56 block assigned and this value must be a valid IPv6 /64 that falls in the VPC range."
+      - "Required if I(assign_instances_ipv6=true)"
+    required: false
+    default: null
+    version_added: "2.5"
   tags:
     description:
       - "A dict of tags to apply to the subnet. Any tags currently applied to the subnet and not present here will be removed."
@@ -45,15 +52,39 @@ options:
     choices: [ 'present', 'absent' ]
   vpc_id:
     description:
-      - "VPC ID of the VPC in which to create the subnet."
+      - "VPC ID of the VPC in which to create or delete the subnet."
-    required: false
+    required: true
     default: null
   map_public:
     description:
-     - "Specify true to indicate that instances launched into the subnet should be assigned public IP address by default."
+      - "Specify true to indicate that instances launched into the subnet should be assigned public IP address by default."
     required: false
     default: false
     version_added: "2.4"
+  assign_instances_ipv6:
+    description:
+      - "Specify true to indicate that instances launched into the subnet should be automatically assigned an IPv6 address."
+    required: false
+    default: false
+    version_added: "2.5"
+  wait:
+    description:
+      - "When specified,I(state=present) module will wait for subnet to be in available state before continuing."
+    required: false
+    default: true
+    version_added: "2.5"
+  wait_timeout:
+    description:
+      - "Number of seconds to wait for subnet to become available I(wait=True)."
+    required: false
+    default: 300
+    version_added: "2.5"
+  purge_tags:
+    description:
+      - Whether or not to remove tags that do not appear in the I(tags) list. Defaults to true.
+    required: false
+    default: true
+    version_added: "2.5"
 extends_documentation_fragment:
     - aws
     - ec2
@@ -77,8 +108,112 @@ EXAMPLES = '''
     vpc_id: vpc-123456
     cidr: 10.0.1.16/28
 
+- name: Create subnet with IPv6 block assigned
+  ec2_vpc_subnet:
+    state: present
+    vpc_id: vpc-123456
+    cidr: 10.1.100.0/24
+    ipv6_cidr: 2001:db8:0:102::/64
+
+- name: Remove IPv6 block assigned to subnet
+  ec2_vpc_subnet:
+    state: present
+    vpc_id: vpc-123456
+    cidr: 10.1.100.0/24
+    ipv6_cidr: ''
 '''
 
+RETURN = '''
+subnet:
+    description: Dictionary of subnet values
+    returned: I(state=present)
+    type: complex
+    contains:
+        id:
+            description: Subnet resource id
+            returned: I(state=present)
+            type: string
+            sample: subnet-b883b2c4
+        cidr_block:
+            description: The IPv4 CIDR of the Subnet
+            returned: I(state=present)
+            type: string
+            sample: "10.0.0.0/16"
+        ipv6_cidr_block:
+            description: The IPv6 CIDR block actively associated with the Subnet
+            returned: I(state=present)
+            type: string
+            sample: "2001:db8:0:102::/64"
+        availability_zone:
+            description: Availability zone of the Subnet
+            returned: I(state=present)
+            type: string
+            sample: us-east-1a
+        state:
+            description: state of the Subnet
+            returned: I(state=present)
+            type: string
+            sample: available
+        tags:
+            description: tags attached to the Subnet, includes name
+            returned: I(state=present)
+            type: dict
+            sample: {"Name": "My Subnet", "env": "staging"}
+        map_public_ip_on_launch:
+            description: whether public IP is auto-assigned to new instances
+            returned: I(state=present)
+            type: boolean
+            sample: false
+        assign_ipv6_address_on_creation:
+            description: whether IPv6 address is auto-assigned to new instances
+            returned: I(state=present)
+            type: boolean
+            sample: false
+        vpc_id:
+            description: the id of the VPC where this Subnet exists
+            returned: I(state=present)
+            type: string
+            sample: vpc-67236184
+        available_ip_address_count:
+            description: number of available IPv4 addresses
+            returned: I(state=present)
+            type: string
+            sample: 251
+        default_for_az:
+            description: indicates whether this is the default Subnet for this Availability Zone
+            returned: I(state=present)
+            type: boolean
+            sample: false
+        ipv6_association_id:
+            description: The IPv6 association ID for the currently associated CIDR
+            returned: I(state=present)
+            type: string
+            sample: subnet-cidr-assoc-b85c74d2
+        ipv6_cidr_block_association_set:
+            description: An array of IPv6 cidr block association set information.
+            returned: I(state=present)
+            type: complex
+            contains:
+                association_id:
+                    description: The association ID
+                    returned: always
+                    type: string
+                ipv6_cidr_block:
+                    description: The IPv6 CIDR block that is associated with the subnet.
+                    returned: always
+                    type: string
+                ipv6_cidr_block_state:
+                    description: A hash/dict that contains a single item. The state of the cidr block association.
+                    returned: always
+                    type: dict
+                    contains:
+                        state:
+                            description: The CIDR block association state.
+                            returned: always
+                            type: string
+'''
+
+
 import time
 import traceback
 
@@ -90,7 +225,7 @@ except ImportError:
 from ansible.module_utils.aws.core import AnsibleAWSModule
 from ansible.module_utils.ec2 import (ansible_dict_to_boto3_filter_list, ansible_dict_to_boto3_tag_list,
                                       ec2_argument_spec, camel_dict_to_snake_dict, get_aws_connection_info,
-                                      boto3_conn, boto3_tag_list_to_ansible_dict, AWSRetry)
+                                      boto3_conn, boto3_tag_list_to_ansible_dict, compare_aws_tags, AWSRetry)
 
 
 def get_subnet_info(subnet):
@@ -110,6 +245,15 @@ def get_subnet_info(subnet):
         subnet['id'] = subnet['subnet_id']
         del subnet['subnet_id']
 
+    subnet['ipv6_cidr_block'] = ''
+    subnet['ipv6_association_id'] = ''
+    ipv6set = subnet.get('ipv6_cidr_block_association_set')
+    if ipv6set:
+        for item in ipv6set:
+            if item.get('ipv6_cidr_block_state', {}).get('state') in ('associated', 'associating'):
+                subnet['ipv6_cidr_block'] = item['ipv6_cidr_block']
+                subnet['ipv6_association_id'] = item['association_id']
+
     return subnet
 
 
@@ -118,56 +262,75 @@ def describe_subnets_with_backoff(client, **params):
     return client.describe_subnets(**params)
 
 
-def subnet_exists(conn, module, subnet_id):
+def create_subnet(conn, module, vpc_id, cidr, ipv6_cidr=None, az=None):
-    filters = ansible_dict_to_boto3_filter_list({'subnet-id': subnet_id})
+    wait = module.params['wait']
-    try:
+    wait_timeout = module.params['wait_timeout']
-        subnets = get_subnet_info(describe_subnets_with_backoff(conn, Filters=filters))
-    except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
-        module.fail_json_aws(e, msg="Couldn't check if subnet exists")
-    if len(subnets) > 0 and 'state' in subnets[0] and subnets[0]['state'] == "available":
-        return subnets[0]
-    else:
-        return False
 
+    params = dict(VpcId=vpc_id,
+                  CidrBlock=cidr)
+
+    if ipv6_cidr:
+        params['Ipv6CidrBlock'] = ipv6_cidr
 
-def create_subnet(conn, module, vpc_id, cidr, az, check_mode):
-    if check_mode:
-        return
-    params = dict(VpcId=vpc_id, CidrBlock=cidr)
     if az:
         params['AvailabilityZone'] = az
+
     try:
-        new_subnet = get_subnet_info(conn.create_subnet(**params))
+        subnet = get_subnet_info(conn.create_subnet(**params))
     except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
         module.fail_json_aws(e, msg="Couldn't create subnet")
+
     # Sometimes AWS takes its time to create a subnet and so using
     # new subnets's id to do things like create tags results in
-    # exception.  boto doesn't seem to refresh 'state' of the newly
+    # exception.
-    # created subnet, i.e.: it's always 'pending'.
+    if wait and subnet.get('state') != 'available':
-    subnet = False
+        delay = 5
-    while subnet is False:
+        max_attempts = wait_timeout / delay
-        subnet = subnet_exists(conn, module, new_subnet['id'])
+        waiter_config = dict(Delay=delay, MaxAttempts=max_attempts)
-        time.sleep(0.1)
+        waiter = conn.get_waiter('subnet_available')
+        try:
+            waiter.wait(SubnetIds=[subnet['id']], WaiterConfig=waiter_config)
+            subnet['state'] = 'available'
+        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
+            module.fail_json(msg="Create subnet action timed out waiting for Subnet to become available.")
 
     return subnet
 
 
-def ensure_tags(conn, module, subnet, tags, add_only, check_mode):
+def ensure_tags(conn, module, subnet, tags, purge_tags):
-    cur_tags = subnet['tags']
+    changed = False
 
-    to_delete = dict((k, cur_tags[k]) for k in cur_tags if k not in tags)
+    filters = ansible_dict_to_boto3_filter_list({'resource-id': subnet['id'], 'resource-type': 'subnet'})
-    if to_delete and not add_only and not check_mode:
+    try:
+        cur_tags = conn.describe_tags(Filters=filters)
+    except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
+        module.fail_json_aws(e, msg="Couldn't describe tags")
+
+    to_update, to_delete = compare_aws_tags(boto3_tag_list_to_ansible_dict(cur_tags.get('Tags')), tags, purge_tags)
+
+    if to_update:
         try:
-            conn.delete_tags(Resources=[subnet['id']], Tags=ansible_dict_to_boto3_tag_list(to_delete))
+            if not module.check_mode:
+                conn.create_tags(Resources=[subnet['id']], Tags=ansible_dict_to_boto3_tag_list(to_update))
+
+            changed = True
+        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
+            module.fail_json_aws(e, msg="Couldn't create tags")
+
+    if to_delete:
+        try:
+            if not module.check_mode:
+                tags_list = []
+                for key in to_delete:
+                    tags_list.append({'Key': key})
+
+                conn.delete_tags(Resources=[subnet['id']], Tags=tags_list)
+
+            changed = True
         except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
             module.fail_json_aws(e, msg="Couldn't delete tags")
 
-    to_add = dict((k, tags[k]) for k in tags if k not in cur_tags or cur_tags[k] != tags[k])
+    return changed
-    if to_add and not check_mode:
-        try:
-            conn.create_tags(Resources=[subnet['id']], Tags=ansible_dict_to_boto3_tag_list(to_add))
-        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
-            module.fail_json_aws(e, msg="Couldn't create tags")
 
 
 def ensure_map_public(conn, module, subnet, map_public, check_mode):
@@ -179,25 +342,89 @@ def ensure_map_public(conn, module, subnet, map_public, check_mode):
         module.fail_json_aws(e, msg="Couldn't modify subnet attribute")
 
 
+def ensure_assign_ipv6_on_create(conn, module, subnet, assign_instances_ipv6, check_mode):
+    if check_mode:
+        return
+
+    try:
+        conn.modify_subnet_attribute(SubnetId=subnet['id'], AssignIpv6AddressOnCreation={'Value': assign_instances_ipv6})
+    except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
+        module.fail_json_aws(e, msg="Couldn't modify subnet attribute")
+
+
+def disassociate_ipv6_cidr(conn, module, subnet):
+    if subnet.get('assign_ipv6_address_on_creation'):
+        ensure_assign_ipv6_on_create(conn, module, subnet, False, False)
+
+    try:
+        conn.disassociate_subnet_cidr_block(AssociationId=subnet['ipv6_association_id'])
+    except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
+        module.fail_json_aws(e, msg="Couldn't disassociate ipv6 cidr block id {0} from subnet {1}"
+                             .format(subnet['ipv6_association_id'], subnet['id']))
+
+
+def ensure_ipv6_cidr_block(conn, module, subnet, ipv6_cidr, check_mode):
+    changed = False
+
+    if subnet['ipv6_association_id'] and not ipv6_cidr:
+        if not check_mode:
+            disassociate_ipv6_cidr(conn, module, subnet)
+        changed = True
+
+    if ipv6_cidr:
+        filters = ansible_dict_to_boto3_filter_list({'ipv6-cidr-block-association.ipv6-cidr-block': ipv6_cidr,
+                                                     'vpc-id': subnet['vpc_id']})
+
+        try:
+            check_subnets = get_subnet_info(describe_subnets_with_backoff(conn, Filters=filters))
+        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
+            module.fail_json_aws(e, msg="Couldn't get subnet info")
+
+        if check_subnets and check_subnets[0]['ipv6_cidr_block']:
+            module.fail_json(msg="The IPv6 CIDR '{0}' conflicts with another subnet".format(ipv6_cidr))
+
+        if subnet['ipv6_association_id']:
+            if not check_mode:
+                disassociate_ipv6_cidr(conn, module, subnet)
+            changed = True
+
+        try:
+            if not check_mode:
+                associate_resp = conn.associate_subnet_cidr_block(SubnetId=subnet['id'], Ipv6CidrBlock=ipv6_cidr)
+            changed = True
+        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
+            module.fail_json_aws(e, msg="Couldn't associate ipv6 cidr {0} to {1}".format(ipv6_cidr, subnet['id']))
+
+        if associate_resp.get('Ipv6CidrBlockAssociation', {}).get('AssociationId'):
+            subnet['ipv6_association_id'] = associate_resp['Ipv6CidrBlockAssociation']['AssociationId']
+            subnet['ipv6_cidr_block'] = associate_resp['Ipv6CidrBlockAssociation']['Ipv6CidrBlock']
+            if subnet['ipv6_cidr_block_association_set']:
+                subnet['ipv6_cidr_block_association_set'][0] = camel_dict_to_snake_dict(associate_resp['Ipv6CidrBlockAssociation'])
+            else:
+                subnet['ipv6_cidr_block_association_set'].append(camel_dict_to_snake_dict(associate_resp['Ipv6CidrBlockAssociation']))
+
+    return changed
+
+
 def get_matching_subnet(conn, module, vpc_id, cidr):
     filters = ansible_dict_to_boto3_filter_list({'vpc-id': vpc_id, 'cidr-block': cidr})
     try:
-        subnets = get_subnet_info(conn.describe_subnets(Filters=filters))
+        subnets = get_subnet_info(describe_subnets_with_backoff(conn, Filters=filters))
     except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
         module.fail_json_aws(e, msg="Couldn't get matching subnet")
 
-    if len(subnets) > 0:
+    if subnets:
         return subnets[0]
-    else:
+
-        return None
+    return None
 
 
-def ensure_subnet_present(conn, module, vpc_id, cidr, az, tags, map_public, check_mode):
+def ensure_subnet_present(conn, module):
-    subnet = get_matching_subnet(conn, module, vpc_id, cidr)
+    subnet = get_matching_subnet(conn, module, module.params['vpc_id'], module.params['cidr'])
     changed = False
     if subnet is None:
-        if not check_mode:
+        if not module.check_mode:
-            subnet = create_subnet(conn, module, vpc_id, cidr, az, check_mode)
+            subnet = create_subnet(conn, module, module.params['vpc_id'], module.params['cidr'], ipv6_cidr=module.params['ipv6_cidr'], az=module.params['az'])
         changed = True
         # Subnet will be None when check_mode is true
         if subnet is None:
@@ -205,30 +432,39 @@ def ensure_subnet_present(conn, module, vpc_id, cidr, az, tags, map_public, chec
                 'changed': changed,
                 'subnet': {}
             }
-    if map_public != subnet['map_public_ip_on_launch']:
+
-        ensure_map_public(conn, module, subnet, map_public, check_mode)
+    if module.params['ipv6_cidr'] != subnet.get('ipv6_cidr_block'):
-        subnet['map_public_ip_on_launch'] = map_public
+        if ensure_ipv6_cidr_block(conn, module, subnet, module.params['ipv6_cidr'], module.check_mode):
+            changed = True
+
+    if module.params['map_public'] != subnet['map_public_ip_on_launch']:
+        ensure_map_public(conn, module, subnet, module.params['map_public'], module.check_mode)
         changed = True
 
-    if tags != subnet['tags']:
+    if module.params['assign_instances_ipv6'] != subnet.get('assign_ipv6_address_on_creation'):
-        ensure_tags(conn, module, subnet, tags, False, check_mode)
+        ensure_assign_ipv6_on_create(conn, module, subnet, module.params['assign_instances_ipv6'], module.check_mode)
-        subnet['tags'] = tags
         changed = True
 
+    if module.params['tags'] != subnet['tags']:
+        if ensure_tags(conn, module, subnet, module.params['tags'], module.params['purge_tags']):
+            changed = True
+
+    subnet = get_matching_subnet(conn, module, module.params['vpc_id'], module.params['cidr'])
+
     return {
         'changed': changed,
         'subnet': subnet
     }
 
 
-def ensure_subnet_absent(conn, module, vpc_id, cidr, check_mode):
+def ensure_subnet_absent(conn, module):
-    subnet = get_matching_subnet(conn, module, vpc_id, cidr)
+    subnet = get_matching_subnet(conn, module, module.params['vpc_id'], module.params['cidr'])
     if subnet is None:
         return {'changed': False}
 
     try:
-        if not check_mode:
+        if not module.check_mode:
-            conn.delete_subnet(SubnetId=subnet['id'], DryRun=check_mode)
+            conn.delete_subnet(SubnetId=subnet['id'])
         return {'changed': True}
     except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
         module.fail_json_aws(e, msg="Couldn't delete subnet")
@@ -240,36 +476,35 @@ def main():
         dict(
             az=dict(default=None, required=False),
             cidr=dict(default=None, required=True),
+            ipv6_cidr=dict(default='', required=False),
             state=dict(default='present', choices=['present', 'absent']),
             tags=dict(default={}, required=False, type='dict', aliases=['resource_tags']),
             vpc_id=dict(default=None, required=True),
-            map_public=dict(default=False, required=False, type='bool')
+            map_public=dict(default=False, required=False, type='bool'),
+            assign_instances_ipv6=dict(default=False, required=False, type='bool'),
+            wait=dict(type='bool', default=True),
+            wait_timeout=dict(type='int', default=300, required=False),
+            purge_tags=dict(default=True, type='bool')
         )
     )
 
-    module = AnsibleAWSModule(argument_spec=argument_spec, supports_check_mode=True)
+    required_if = [('assign_instances_ipv6', True, ['ipv6_cidr'])]
+
+    module = AnsibleAWSModule(argument_spec=argument_spec, supports_check_mode=True, required_if=required_if)
+
+    if module.params.get('assign_instances_ipv6') and not module.params.get('ipv6_cidr'):
+        module.fail_json(msg="assign_instances_ipv6 is True but ipv6_cidr is None or an empty string")
 
     region, ec2_url, aws_connect_params = get_aws_connection_info(module, boto3=True)
+    connection = boto3_conn(module, conn_type='client', resource='ec2', region=region, endpoint=ec2_url, **aws_connect_params)
 
-    if region:
-        connection = boto3_conn(module, conn_type='client', resource='ec2', region=region, endpoint=ec2_url, **aws_connect_params)
-    else:
-        module.fail_json(msg="region must be specified")
-
-    vpc_id = module.params.get('vpc_id')
-    tags = module.params.get('tags')
-    cidr = module.params.get('cidr')
-    az = module.params.get('az')
     state = module.params.get('state')
-    map_public = module.params.get('map_public')
 
     try:
         if state == 'present':
-            result = ensure_subnet_present(connection, module, vpc_id, cidr, az, tags, map_public,
+            result = ensure_subnet_present(connection, module)
-                                           check_mode=module.check_mode)
         elif state == 'absent':
-            result = ensure_subnet_absent(connection, module, vpc_id, cidr,
+            result = ensure_subnet_absent(connection, module)
-                                          check_mode=module.check_mode)
     except botocore.exceptions.ClientError as e:
         module.fail_json(msg=e.message, exception=traceback.format_exc(),
                          **camel_dict_to_snake_dict(e.response))

test/integration/targets/ec2_vpc_subnet/tasks/main.yml

@@ -16,7 +16,7 @@
         name: "{{ resource_prefix }}-vpc"
         state: present
         cidr_block: "10.232.232.128/26"
-        region: '{{ec2_region}}'
+        region: '{{ ec2_region }}'
         aws_access_key: '{{ aws_access_key }}'
         aws_secret_key: '{{ aws_secret_key }}'
         security_token: '{{ security_token }}'
@@ -33,7 +33,7 @@
         tags:
           Name: '{{ec2_vpc_subnet_name}}'
           Description: '{{ec2_vpc_subnet_description}}'
-        region: '{{ec2_region}}'
+        region: '{{ ec2_region }}'
         aws_access_key: '{{ aws_access_key }}'
         aws_secret_key: '{{ aws_secret_key }}'
         security_token: '{{ security_token }}'
@@ -56,20 +56,41 @@
         tags:
           Name: '{{ec2_vpc_subnet_name}}'
           Description: '{{ec2_vpc_subnet_description}}'
-        region: '{{ec2_region}}'
+        region: '{{ ec2_region }}'
         aws_access_key: '{{ aws_access_key }}'
         aws_secret_key: '{{ aws_secret_key }}'
         security_token: '{{ security_token }}'
         state: present
       register: vpc_subnet_recreate
 
-    - name: assert recreation changed nothing (expected changed=true)
+    - name: assert recreation changed nothing (expected changed=false)
       assert:
         that:
            - 'not vpc_subnet_recreate.changed'
-           - 'vpc_subnet_recreate.subnet.id.startswith("subnet-")'
+           - 'vpc_subnet_recreate.subnet == vpc_subnet_create.subnet'
-           - '"Name" in vpc_subnet_recreate.subnet.tags and vpc_subnet_recreate.subnet.tags["Name"] == ec2_vpc_subnet_name'
+
-           - '"Description" in vpc_subnet_recreate.subnet.tags and vpc_subnet_recreate.subnet.tags["Description"] == ec2_vpc_subnet_description'
+    - name: add invalid ipv6 block to subnet (expected failed)
+      ec2_vpc_subnet:
+        cidr: "10.232.232.128/28"
+        az: "{{ ec2_region }}a"
+        vpc_id: "{{ vpc_result.vpc.id }}"
+        ipv6_cidr: 2001:db8::/64
+        tags:
+          Name: '{{ec2_vpc_subnet_name}}'
+          Description: '{{ec2_vpc_subnet_description}}'
+        region: '{{ec2_region}}'
+        aws_access_key: '{{ aws_access_key }}'
+        aws_secret_key: '{{ aws_secret_key }}'
+        security_token: '{{ security_token }}'
+        state: present
+      register: vpc_subnet_ipv6_failed
+      ignore_errors: yes
+
+    - name: assert failure happened (expected failed)
+      assert:
+        that:
+           - 'vpc_subnet_ipv6_failed.failed'
+           - "'Couldn\\'t associate ipv6 cidr' in vpc_subnet_ipv6_failed.msg"
 
     - name: add a tag (expected changed=true)
       ec2_vpc_subnet:
@@ -80,7 +101,7 @@
           Name: '{{ec2_vpc_subnet_name}}'
           Description: '{{ec2_vpc_subnet_description}}'
           AnotherTag: SomeValue
-        region: '{{ec2_region}}'
+        region: '{{ ec2_region }}'
         aws_access_key: '{{ aws_access_key }}'
         aws_secret_key: '{{ aws_secret_key }}'
         security_token: '{{ security_token }}'
@@ -95,16 +116,14 @@
            - '"Description" in vpc_subnet_add_a_tag.subnet.tags and vpc_subnet_add_a_tag.subnet.tags["Description"] == ec2_vpc_subnet_description'
            - '"AnotherTag" in vpc_subnet_add_a_tag.subnet.tags and vpc_subnet_add_a_tag.subnet.tags["AnotherTag"] == "SomeValue"'
 
-    # We may want to change this behaviour by adding purge_tags to the module
+    - name: remove tags with default purge_tags=true (expected changed=true)
-    # and setting it to false by default
-    - name: remove tags (expected changed=true)
       ec2_vpc_subnet:
         cidr: "10.232.232.128/28"
         az: "{{ ec2_region }}a"
         vpc_id: "{{ vpc_result.vpc.id }}"
         tags:
           AnotherTag: SomeValue
-        region: '{{ec2_region}}'
+        region: '{{ ec2_region }}'
         aws_access_key: '{{ aws_access_key }}'
         aws_secret_key: '{{ aws_secret_key }}'
         security_token: '{{ security_token }}'
@@ -119,12 +138,36 @@
            - '"Description" not in vpc_subnet_remove_tags.subnet.tags'
            - '"AnotherTag" in vpc_subnet_remove_tags.subnet.tags and vpc_subnet_remove_tags.subnet.tags["AnotherTag"] == "SomeValue"'
 
+    - name: change tags with purge_tags=false (expected changed=true)
+      ec2_vpc_subnet:
+        cidr: "10.232.232.128/28"
+        az: "{{ ec2_region }}a"
+        vpc_id: "{{ vpc_result.vpc.id }}"
+        tags:
+          Name: '{{ec2_vpc_subnet_name}}'
+          Description: '{{ec2_vpc_subnet_description}}'
+        region: '{{ec2_region}}'
+        aws_access_key: '{{ aws_access_key }}'
+        aws_secret_key: '{{ aws_secret_key }}'
+        security_token: '{{ security_token }}'
+        state: present
+        purge_tags: false
+      register: vpc_subnet_change_tags
+
+    - name: assert tag addition happened (expected changed=true)
+      assert:
+        that:
+           - 'vpc_subnet_change_tags.changed'
+           - '"Name" in vpc_subnet_change_tags.subnet.tags and vpc_subnet_change_tags.subnet.tags["Name"] == ec2_vpc_subnet_name'
+           - '"Description" in vpc_subnet_change_tags.subnet.tags and vpc_subnet_change_tags.subnet.tags["Description"] == ec2_vpc_subnet_description'
+           - '"AnotherTag" in vpc_subnet_change_tags.subnet.tags and vpc_subnet_change_tags.subnet.tags["AnotherTag"] == "SomeValue"'
+
     - name: test state=absent (expected changed=true)
       ec2_vpc_subnet:
         cidr: "10.232.232.128/28"
         vpc_id: "{{ vpc_result.vpc.id }}"
         state: absent
-        region: '{{ec2_region}}'
+        region: '{{ ec2_region }}'
         aws_access_key: '{{ aws_access_key }}'
         aws_secret_key: '{{ aws_secret_key }}'
         security_token: '{{ security_token }}'
@@ -166,6 +209,138 @@
       assert:
         that:
            - 'result.changed'
+
+    # FIXME - Replace by creating IPv6 enabled VPC once ec2_vpc_net module supports it.
+    - name: install aws cli - FIXME temporary this should go for a lighterweight solution
+      command: pip install awscli
+
+    - name: Assign an Amazon provided IPv6 CIDR block to the VPC
+      command: aws ec2 associate-vpc-cidr-block --amazon-provided-ipv6-cidr-block --vpc-id '{{ vpc_result.vpc.id }}'
+      environment:
+          AWS_ACCESS_KEY_ID: '{{aws_access_key}}'
+          AWS_SECRET_ACCESS_KEY: '{{aws_secret_key}}'
+          AWS_SESSION_TOKEN: '{{security_token}}'
+          AWS_DEFAULT_REGION: '{{ec2_region}}'
+
+    - name: Get the assigned IPv6 CIDR
+      command: aws ec2 describe-vpcs --vpc-ids '{{ vpc_result.vpc.id }}'
+      environment:
+          AWS_ACCESS_KEY_ID: '{{aws_access_key}}'
+          AWS_SECRET_ACCESS_KEY: '{{aws_secret_key}}'
+          AWS_SESSION_TOKEN: '{{security_token}}'
+          AWS_DEFAULT_REGION: '{{ec2_region}}'
+      register: vpc_ipv6
+
+    - set_fact:
+        vpc_ipv6_cidr: "{{ vpc_ipv6.stdout | from_json | json_query('Vpcs[0].Ipv6CidrBlockAssociationSet[0].Ipv6CidrBlock') }}"
+
+    - name: create subnet with IPv6 (expected changed=true)
+      ec2_vpc_subnet:
+        cidr: "10.232.232.128/28"
+        vpc_id: "{{ vpc_result.vpc.id }}"
+        ipv6_cidr: "{{ vpc_ipv6_cidr | regex_replace('::/56', '::/64') }}"
+        assign_instances_ipv6: true
+        state: present
+        region: '{{ec2_region}}'
+        aws_access_key: '{{ aws_access_key }}'
+        aws_secret_key: '{{ aws_secret_key }}'
+        security_token: '{{ security_token }}'
+        tags:
+          Name: '{{ec2_vpc_subnet_name}}'
+          Description: '{{ec2_vpc_subnet_description}}'
+      register: vpc_subnet_ipv6_create
+
+    - name: assert creation with IPv6 happened (expected changed=true)
+      assert:
+        that:
+           - 'vpc_subnet_ipv6_create'
+           - 'vpc_subnet_ipv6_create.subnet.id.startswith("subnet-")'
+           - "vpc_subnet_ipv6_create.subnet.ipv6_cidr_block == '{{ vpc_ipv6_cidr | regex_replace('::/56', '::/64') }}'"
+           - '"Name" in vpc_subnet_ipv6_create.subnet.tags and vpc_subnet_ipv6_create.subnet.tags["Name"] == ec2_vpc_subnet_name'
+           - '"Description" in vpc_subnet_ipv6_create.subnet.tags and vpc_subnet_ipv6_create.subnet.tags["Description"] == ec2_vpc_subnet_description'
+           - 'vpc_subnet_ipv6_create.subnet.assign_ipv6_address_on_creation'
+
+    - name: recreate subnet (expected changed=false)
+      ec2_vpc_subnet:
+        cidr: "10.232.232.128/28"
+        vpc_id: "{{ vpc_result.vpc.id }}"
+        ipv6_cidr: "{{ vpc_ipv6_cidr | regex_replace('::/56', '::/64') }}"
+        assign_instances_ipv6: true
+        region: '{{ec2_region}}'
+        aws_access_key: '{{ aws_access_key }}'
+        aws_secret_key: '{{ aws_secret_key }}'
+        security_token: '{{ security_token }}'
+        state: present
+        tags:
+          Name: '{{ec2_vpc_subnet_name}}'
+          Description: '{{ec2_vpc_subnet_description}}'
+      register: vpc_subnet_ipv6_recreate
+
+    - name: assert recreation changed nothing (expected changed=false)
+      assert:
+        that:
+           - 'not vpc_subnet_ipv6_recreate.changed'
+           - 'vpc_subnet_ipv6_recreate.subnet == vpc_subnet_ipv6_create.subnet'
+
+    - name: change subnet ipv6 attribute (expected changed=true)
+      ec2_vpc_subnet:
+        cidr: "10.232.232.128/28"
+        vpc_id: "{{ vpc_result.vpc.id }}"
+        ipv6_cidr: "{{ vpc_ipv6_cidr | regex_replace('::/56', '::/64') }}"
+        assign_instances_ipv6: false
+        region: '{{ec2_region}}'
+        aws_access_key: '{{ aws_access_key }}'
+        aws_secret_key: '{{ aws_secret_key }}'
+        security_token: '{{ security_token }}'
+        state: present
+        purge_tags: false
+      register: vpc_change_attribute
+
+    - name: assert assign_instances_ipv6 attribute changed (expected changed=true)
+      assert:
+        that:
+           - 'vpc_change_attribute.changed'
+           - 'not vpc_change_attribute.subnet.assign_ipv6_address_on_creation'
+
+    - name: add second subnet with duplicate ipv6 cidr (expected failure)
+      ec2_vpc_subnet:
+        cidr: "10.232.232.144/28"
+        vpc_id: "{{ vpc_result.vpc.id }}"
+        ipv6_cidr: "{{ vpc_ipv6_cidr | regex_replace('::/56', '::/64') }}"
+        region: '{{ec2_region}}'
+        aws_access_key: '{{ aws_access_key }}'
+        aws_secret_key: '{{ aws_secret_key }}'
+        security_token: '{{ security_token }}'
+        state: present
+        purge_tags: false
+      register: vpc_add_duplicate_ipv6
+      ignore_errors: true
+
+    - name: assert graceful failure (expected failed)
+      assert:
+        that:
+           - 'vpc_add_duplicate_ipv6.failed'
+           - "'The IPv6 CIDR \\'{{ vpc_ipv6_cidr | regex_replace('::/56', '::/64') }}\\' conflicts with another subnet' in vpc_add_duplicate_ipv6.msg"
+
+    - name: remove subnet ipv6 cidr (expected changed=true)
+      ec2_vpc_subnet:
+        cidr: "10.232.232.128/28"
+        vpc_id: "{{ vpc_result.vpc.id }}"
+        region: '{{ec2_region}}'
+        aws_access_key: '{{ aws_access_key }}'
+        aws_secret_key: '{{ aws_secret_key }}'
+        security_token: '{{ security_token }}'
+        state: present
+        purge_tags: false
+      register: vpc_remove_ipv6_cidr
+
+    - name: assert subnet ipv6 cidr removed (expected changed=true)
+      assert:
+        that:
+           - 'vpc_remove_ipv6_cidr.changed'
+           - "vpc_remove_ipv6_cidr.subnet.ipv6_cidr_block == ''"
+           - 'not vpc_remove_ipv6_cidr.subnet.assign_ipv6_address_on_creation'
+
   always:
 
     ################################################
@@ -177,7 +352,7 @@
         cidr: "10.232.232.128/28"
         vpc_id: "{{ vpc_result.vpc.id }}"
         state: absent
-        region: '{{ec2_region}}'
+        region: '{{ ec2_region }}'
         aws_access_key: '{{ aws_access_key }}'
         aws_secret_key: '{{ aws_secret_key }}'
         security_token: '{{ security_token }}'
@@ -187,7 +362,7 @@
         name: "{{ resource_prefix }}-vpc"
         state: absent
         cidr_block: "10.232.232.128/26"
-        region: '{{ec2_region}}'
+        region: '{{ ec2_region }}'
         aws_access_key: '{{ aws_access_key }}'
         aws_secret_key: '{{ aws_secret_key }}'
         security_token: '{{ security_token }}'