To ipv6 network (#48572)

* Add to_ipv6_subnet function

* Use the correct function for subnet

* Corrected code style and tests

* Corrected testcase assertion

64 bits make 8 octets, or 4 hextets

* Import from correct module directly

lib/ansible/module_utils/common/network.py

@@ -79,6 +79,36 @@ def to_subnet(addr, mask, dotted_notation=False):
     return '%s/%s' % ('.'.join(network), cidr)
 
 
+def to_ipv6_subnet(addr):
+    """ IPv6 addresses are eight groupings. The first four groupings (64 bits) comprise the subnet address. """
+
+    # https://tools.ietf.org/rfc/rfc2374.txt
+
+    # Split by :: to identify omitted zeros
+    ipv6_prefix = addr.split('::')[0]
+
+    # Get the first four groups, or as many as are found + ::
+    found_groups = []
+    for group in ipv6_prefix.split(':'):
+        found_groups.append(group)
+        if len(found_groups) == 4:
+            break
+    if len(found_groups) < 4:
+        found_groups.append('::')
+
+    # Concatenate network address parts
+    network_addr = ''
+    for group in found_groups:
+        if group != '::':
+            network_addr += str(group)
+        network_addr += str(':')
+
+    # Ensure network address ends with ::
+    if not network_addr.endswith('::'):
+        network_addr += str(':')
+    return network_addr
+
+
 def to_ipv6_network(addr):
     """ IPv6 addresses are eight groupings. The first three groupings (48 bits) comprise the network address. """
 

lib/ansible/modules/cloud/amazon/ec2_group.py

@@ -303,7 +303,7 @@ from ansible.module_utils.aws.iam import get_aws_account_id
 from ansible.module_utils.aws.waiters import get_waiter
 from ansible.module_utils.ec2 import AWSRetry, camel_dict_to_snake_dict, compare_aws_tags
 from ansible.module_utils.ec2 import ansible_dict_to_boto3_filter_list, boto3_tag_list_to_ansible_dict, ansible_dict_to_boto3_tag_list
-from ansible.module_utils.network.common.utils import to_ipv6_network, to_subnet
+from ansible.module_utils.common.network import to_ipv6_subnet, to_subnet
 from ansible.module_utils._text import to_text
 from ansible.module_utils.six import string_types
 
@@ -726,7 +726,7 @@ def validate_ip(module, cidr_ip):
         try:
             ip = to_subnet(split_addr[0], split_addr[1])
         except ValueError:
-            ip = to_ipv6_network(split_addr[0]) + "/" + split_addr[1]
+            ip = to_ipv6_subnet(split_addr[0]) + "/" + split_addr[1]
         if ip != cidr_ip:
             module.warn("One of your CIDR addresses ({0}) has host bits set. To get rid of this warning, "
                         "check the network mask and make sure that only network bits are set: {1}.".format(cidr_ip, ip))