Fix broken ec2 volume creation breaks with older boto versions (#1773) (#19723)

Fix issue which prevents creating ec2 instance with extra volumes when
using a older version of boto not supporting volume encryption.

Fix issue #1173

lib/ansible/modules/cloud/amazon/ec2.py

@@ -603,6 +603,8 @@ from ast import literal_eval
 from ansible.module_utils.six import iteritems
 from ansible.module_utils.six import get_function_code
 
+from distutils.version import LooseVersion
+
 try:
     import boto.ec2
     from boto.ec2.blockdevicemapping import BlockDeviceType, BlockDeviceMapping
@@ -768,6 +770,15 @@ def boto_supports_profile_name_arg(ec2):
     run_instances_method = getattr(ec2, 'run_instances')
     return 'instance_profile_name' in get_function_code(run_instances_method).co_varnames
 
+def boto_supports_volume_encryption():
+    """
+    Check if Boto library supports encryption of EBS volumes (added in 2.29.0)
+
+    Returns:
+        True if boto library has the named param as an argument on the request_spot_instances method, else False
+    """
+    return hasattr(boto, 'Version') and LooseVersion(boto.Version) >= LooseVersion('2.29.0')
+
 def create_block_device(module, ec2, volume):
     # Not aware of a way to determine this programatically
     # http://aws.amazon.com/about-aws/whats-new/2013/10/09/ebs-provisioned-iops-maximum-iops-gb-ratio-increased-to-30-1/
@@ -798,6 +809,7 @@ def create_block_device(module, ec2, volume):
     if 'ephemeral' in volume:
         if 'snapshot' in volume:
             module.fail_json(msg = 'Cannot set both ephemeral and snapshot')
+    if boto_supports_volume_encryption():
         return BlockDeviceType(snapshot_id=volume.get('snapshot'),
                                ephemeral_name=volume.get('ephemeral'),
                                size=volume.get('volume_size'),
@@ -805,6 +817,13 @@ def create_block_device(module, ec2, volume):
                                delete_on_termination=volume.get('delete_on_termination', False),
                                iops=volume.get('iops'),
                                encrypted=volume.get('encrypted', None))
+    else:
+        return BlockDeviceType(snapshot_id=volume.get('snapshot'),
+                               ephemeral_name=volume.get('ephemeral'),
+                               size=volume.get('volume_size'),
+                               volume_type=volume_type,
+                               delete_on_termination=volume.get('delete_on_termination', False),
+                               iops=volume.get('iops'))
 
 def boto_supports_param_in_spot_request(ec2, param):
     """