[cloud] New module: Add module to set Amazon AWS DynamoDB TTL (cloud/amazon/dynamodb_ttl) (#22588)

* add aws dynamo_ttl module, small parameter setter

 - New Module Pull Request

`dynamodb_ttl`

2.3.0/devel

Very self-contained TTL setter. This is independent of the dynamodb_table module
as it's really designed to be a helper for tables that may be created in other
ways (say, CloudFormation, which doesn't support setting TTL).

* committer is no longer a valid value

* bump version_added, catch common exceptions

* pep8 fixes

* one more pep8

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

@@ -0,0 +1,182 @@
+#!/usr/bin/python
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+ANSIBLE_METADATA = {'metadata_version': '1.0',
+                    'status': ['preview'],
+                    'supported_by': 'community'}
+
+DOCUMENTATION = '''
+---
+module: dynamodb_ttl
+short_description: set TTL for a given DynamoDB table.
+description:
+- Uses boto3 to set TTL.
+- requires botocore version 1.5.24 or higher.
+version_added: "2.4"
+options:
+  state:
+    description:
+    - state to set DynamoDB table to
+    choices: ['enable', 'disable']
+    required: false
+    default: enable
+  table_name:
+    description:
+    - name of the DynamoDB table to work on
+    required: true
+  attribute_name:
+    description:
+    - the name of the Time to Live attribute used to store the expiration time for items in the table
+    - this appears to be required by the API even when disabling TTL.
+    required: true
+
+author: "Ted (@tedder)"
+extends_documentation_fragment:
+- aws
+- ec2
+requirements: [ botocore>=1.5.24, boto3 ]
+'''
+
+EXAMPLES = '''
+- name: enable TTL on my cowfacts table
+  dynamodb_ttl:
+    state: enable
+    table_name: cowfacts
+    attribute_name: cow_deleted_date
+
+- name: disable TTL on my cowfacts table
+  dynamodb_ttl:
+    state: disable
+    table_name: cowfacts
+    attribute_name: cow_deleted_date
+'''
+
+RETURN = '''
+current_status:
+  description: current or new TTL specification.
+  type: dict
+  returned: always
+  sample:
+  - { "AttributeName": "deploy_timestamp", "TimeToLiveStatus": "ENABLED" }
+  - { "AttributeName": "deploy_timestamp", "Enabled": true }
+'''
+
+# import module snippets
+from ansible.module_utils.basic import AnsibleModule
+from ansible.module_utils.ec2 import ec2_argument_spec, camel_dict_to_snake_dict
+
+# import a class, otherwise we'll use a fully qualified path
+import ansible.module_utils.ec2
+
+import distutils.version
+
+try:
+    import botocore
+    HAS_BOTO3 = True
+except ImportError:
+    HAS_BOTO3 = False
+
+
+def get_current_ttl_state(c, table_name):
+    '''Fetch the state dict for a table.'''
+    current_state = c.describe_time_to_live(TableName=table_name)
+    return current_state.get('TimeToLiveDescription')
+
+
+def does_state_need_changing(attribute_name, desired_state, current_spec):
+    '''Run checks to see if the table needs to be modified. Basically a dirty check.'''
+    if not current_spec:
+        # we don't have an entry (or a table?)
+        return True
+
+    if desired_state.lower() == 'enable' and current_spec.get('TimeToLiveStatus') not in ['ENABLING', 'ENABLED']:
+        return True
+    if desired_state.lower() == 'disable' and current_spec.get('TimeToLiveStatus') not in ['DISABLING', 'DISABLED']:
+        return True
+    if attribute_name != current_spec.get('AttributeName'):
+        return True
+
+    return False
+
+
+def set_ttl_state(c, table_name, state, attribute_name):
+    '''Set our specification. Returns the update_time_to_live specification dict,
+       which is different than the describe_* call.'''
+    is_enabled = False
+    if state.lower() == 'enable':
+        is_enabled = True
+
+    ret = c.update_time_to_live(
+        TableName=table_name,
+        TimeToLiveSpecification={
+            'Enabled': is_enabled,
+            'AttributeName': attribute_name
+        }
+    )
+
+    return ret.get('TimeToLiveSpecification')
+
+
+def main():
+    argument_spec = ec2_argument_spec()
+    argument_spec.update(dict(
+        state=dict(choices=['enable', 'disable']),
+        table_name=dict(required=True),
+        attribute_name=dict(required=True))
+    )
+    module = AnsibleModule(
+        argument_spec=argument_spec,
+    )
+
+    if not HAS_BOTO3:
+        module.fail_json(msg='boto3 required for this module')
+    elif distutils.version.StrictVersion(botocore.__version__) < distutils.version.StrictVersion('1.5.24'):
+        # TTL was added in this version.
+        module.fail_json(msg='Found botocore in version {0}, but >= {1} is required for TTL support'.format(botocore.__version__, '1.5.24'))
+
+    try:
+        region, ec2_url, aws_connect_kwargs = ansible.module_utils.ec2.get_aws_connection_info(module, boto3=True)
+        dbclient = ansible.module_utils.ec2.boto3_conn(module, conn_type='client', resource='dynamodb', region=region, endpoint=ec2_url, **aws_connect_kwargs)
+    except botocore.exceptions.NoCredentialsError as e:
+        module.fail_json(msg=str(e))
+
+    result = {'changed': False}
+    state = module.params['state']
+
+    # wrap all our calls to catch the standard exceptions. We don't pass `module` in to the
+    # methods so it's easier to do here.
+    try:
+        current_state = get_current_ttl_state(dbclient, module.params['table_name'])
+
+        if does_state_need_changing(module.params['attribute_name'], module.params['state'], current_state):
+            # changes needed
+            new_state = set_ttl_state(dbclient, module.params['table_name'], module.params['state'], module.params['attribute_name'])
+            result['current_status'] = new_state
+            result['changed'] = True
+        else:
+            # no changes needed
+            result['current_status'] = current_state
+
+    except (botocore.exceptions.ClientError, botocore.exceptions.ParamValidationError) as e:
+        module.fail_json(msg=e.message, **camel_dict_to_snake_dict(e.response))
+    except ValueError as e:
+        module.fail_json(msg=str(e))
+
+    module.exit_json(**result)
+
+
+if __name__ == '__main__':
+    main()