New module: elasticache_parameter_group for modifying Elasticache cluster settings

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

@@ -0,0 +1,332 @@
+#!/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 = {'status': ['preview'],
+                    'supported_by': 'community',
+                    'version': '1.0'}
+
+DOCUMENTATION = """
+---
+module: elasticache_group_parameter
+short_description: Manage cache security groups in Amazon Elasticache.
+description:
+  - Manage cache security groups in Amazon Elasticache.
+  - Returns information about the specified cache cluster.
+version_added: "2.3"
+author: "Sloane Hertel (@s-hertel)"
+options:
+  group_family:
+    description:
+      - The name of the cache parameter group family that the cache parameter group can be used with.
+    choices: ['memcached1.4', 'redis2.6', 'redis2.8', 'redis3.2']
+    required: yes
+    type: string
+  name:
+    description:
+     - A user-specified name for the cache parameter group.
+    required: yes
+    type: string
+  description:
+    description:
+      - A user-specified description for the cache parameter group.
+  state:
+    description:
+      - Idempotent actions that will create/modify, destroy, or reset a cache parameter group as needed.
+    choices: ['present', 'absent', 'reset']
+    required: true
+  values:
+    description:
+      - A user-specified list of parameters to reset or modify for the cache parameter group.
+    required: no
+    type: dict
+    default: None
+"""
+
+EXAMPLES = """
+# Note: None of these examples set aws_access_key, aws_secret_key, or region.
+# It is assumed that their matching environment variables are set.
+---
+- hosts: localhost
+  connection: local
+  tasks:
+    - name: 'Create a test parameter group'
+      elasticache_parameter_group:
+        name: 'test-param-group'
+        group_family: 'redis3.2'
+        description: 'This is a cache parameter group'
+        state: 'present'
+    - name: 'Modify a test parameter group'
+      elasticache_parameter_group:
+        name: 'test-param-group'
+        values:
+          - ['activerehashing', 'yes']
+          - ['client-output-buffer-limit-normal-hard-limit', 4]
+        state: 'present'
+    - name: 'Reset all modifiable parameters for the test parameter group'
+      elasticache_parameter_group:
+        name: 'test-param-group'
+        state: reset
+    - name: 'Delete a test parameter group'
+      elasticache_parameter_group:
+        name: 'test-param-group'
+        state: 'absent'
+"""
+
+RETURN = """
+elasticache:
+  description: cache parameter group information and response metadata
+  returned: always
+  type: dict
+  sample:
+    cache_parameter_group:
+      cache_parameter_group_family: redis3.2
+      cache_parameter_group_name: test-please-delete
+      description: "initial description"
+    response_metadata:
+      http_headers:
+        content-length: "562"
+        content-type: text/xml
+        date: "Mon, 06 Feb 2017 22:14:08 GMT"
+        x-amzn-requestid: 947291f9-ecb9-11e6-85bd-3baa4eca2cc1
+      http_status_code: 200
+      request_id: 947291f9-ecb9-11e6-85bd-3baa4eca2cc1
+      retry_attempts: 0
+changed:
+  description: if the cache parameter group has changed
+  returned: always
+  type: bool
+  sample:
+    changed: true
+"""
+
+# import module snippets
+from ansible.module_utils.basic import AnsibleModule
+from ansible.module_utils.ec2 import boto3_conn, get_aws_connection_info, ec2_argument_spec, camel_dict_to_snake_dict
+from ansible.module_utils.six import text_type
+import traceback
+
+try:
+    import boto3
+    import botocore
+    HAS_BOTO3 = True
+except ImportError:
+    HAS_BOTO3 = False
+
+def create(module, conn, name, group_family, description):
+    """ Create ElastiCache parameter group. """
+    try:
+        response = conn.create_cache_parameter_group(CacheParameterGroupName=name, CacheParameterGroupFamily=group_family, Description=description)
+        changed = True
+    except boto.exception.BotoServerError as e:
+        module.fail_json(msg="Unable to create cache parameter group.", exception=traceback.format_exc(e))
+    return response, changed
+
+def delete(module, conn, name):
+    """ Delete ElastiCache parameter group. """
+    try:
+        conn.delete_cache_parameter_group(CacheParameterGroupName=name)
+        response = {}
+        changed = True
+    except boto.exception.BotoServerError as e:
+        module.fail_json(msg="Unable to delete cache parameter group.", exception=traceback.format_exc(e))
+    return response, changed
+
+def make_current_modifiable_param_dict(module, conn, name):
+    """ Gets the current state of the cache parameter group and creates a dict with the format: {ParameterName: [Allowed_Values, DataType, ParameterValue]}"""
+    current_info = get_info(conn, name)
+    if current_info is False:
+        module.fail_json(msg="Could not connect to the cache parameter group %s." % name)
+
+    parameters = current_info["Parameters"]
+    modifiable_params = {}
+
+    for param in parameters:
+        if param["IsModifiable"] and ("AllowedValues" and "ParameterValue") in param:
+            modifiable_params[param["ParameterName"]] = [param["AllowedValues"], param["DataType"], param["ParameterValue"]]
+    return modifiable_params
+
+def check_valid_modification(module, values, modifiable_params):
+    """ Check if the parameters and values in values are valid.  """
+    changed_with_update = False
+
+    for parameter in values:
+        new_value = values[parameter]
+
+        # check valid modifiable parameters
+        if parameter not in modifiable_params:
+            module.fail_json("%s is not a modifiable parameter. Valid parameters to modify are: %s." % (parameter, modifiable_params.keys()))
+
+        # check allowed datatype for modified parameters
+        str_to_type = {"integer": int, "string": text_type}
+        if not isinstance(new_value, str_to_type[modifiable_params[parameter][1]]):
+            module.fail_json(msg="%s (type %s) is not an allowed value for the parameter %s. Expected a type %s." %
+                             (new_value, type(new_value), parameter, modifiable_params[parameter][1]))
+
+        # check allowed values for modifiable parameters
+        if text_type(new_value) not in modifiable_params[parameter][0] and not isinstance(new_value, int):
+            module.fail_json(msg="%s is not an allowed value for the parameter %s. Valid parameters are: %s." %
+                                 (new_value, parameter, modifiable_params[parameter][0]))
+
+        # check if a new value is different from current value
+        if text_type(new_value) != modifiable_params[parameter][2]:
+            changed_with_update = True
+
+    return changed_with_update
+
+def check_changed_parameter_values(values, old_parameters, new_parameters):
+    """ Checking if the new values are different than the old values.  """
+    changed_with_update = False
+
+    # if the user specified parameters to reset, only check those for change
+    if values:
+        for parameter in values:
+            if old_parameters[parameter] != new_parameters[parameter]:
+                changed_with_update = True
+                break
+    # otherwise check all to find a change
+    else:
+        for parameter in old_parameters:
+            if old_parameters[parameter] != new_parameters[parameter]:
+                changed_with_update = True
+                break
+
+    return changed_with_update
+
+def modify(module, conn, name, values):
+    """ Modify ElastiCache parameter group to reflect the new information if it differs from the current. """
+    # compares current group parameters with the parameters we've specified to to a value to see if this will change the group
+    format_parameters = []
+    for key in values:
+        value = text_type(values[key])
+        format_parameters.append({'ParameterName': key, 'ParameterValue': value})
+    try:
+        response = conn.modify_cache_parameter_group(CacheParameterGroupName=name, ParameterNameValues=format_parameters)
+    except boto.exception.BotoServerError as e:
+        module.fail_json(msg="Unable to modify cache parameter group.", exception=traceback.format_exc(e))
+    return response
+
+def reset(module, conn, name, values):
+    """ Reset ElastiCache parameter group if the current information is different from the new information. """
+    # used to compare with the reset parameters' dict to see if there have been changes
+    old_parameters_dict = make_current_modifiable_param_dict(module, conn, name)
+
+    format_parameters = []
+
+    # determine whether to reset all or specific parameters
+    if values:
+        all_parameters = False
+        format_parameters = []
+        for key in values:
+            value = text_type(values[key])
+            format_parameters.append({'ParameterName': key, 'ParameterValue': value})
+    else:
+        all_parameters = True
+
+    try:
+        response = conn.reset_cache_parameter_group(CacheParameterGroupName=name, ParameterNameValues=format_parameters, ResetAllParameters=all_parameters)
+    except boto.exception.BotoServerError as e:
+        module.fail_json(msg="Unable to reset cache parameter group.", exception=traceback.format_exc(e))
+
+    # determine changed
+    new_parameters_dict = make_current_modifiable_param_dict(module, conn, name)
+    changed = check_changed_parameter_values(values, old_parameters_dict, new_parameters_dict)
+
+    return response, changed
+
+def get_info(conn, name):
+    """ Gets info about the ElastiCache parameter group. Returns false if it doesn't exist or we don't have access. """
+    try:
+        data = conn.describe_cache_parameters(CacheParameterGroupName=name)
+        return data
+    except botocore.exceptions.ClientError as e:
+        return False
+
+
+def main():
+    argument_spec = ec2_argument_spec()
+    argument_spec.update(
+        dict(
+            group_family=dict(type='str', choices=['memcached1.4', 'redis2.6', 'redis2.8', 'redis3.2']),
+            name=dict(required=True, type='str'),
+            description=dict(type='str'),
+            state=dict(required=True),
+            values=dict(type='dict'),
+        )
+    )
+    module = AnsibleModule(argument_spec=argument_spec)
+
+    if not HAS_BOTO3:
+        module.fail_json(msg='boto required for this module')
+
+    parameter_group_family = module.params.get('group_family')
+    parameter_group_name = module.params.get('name')
+    group_description = module.params.get('description')
+    state = module.params.get('state')
+    values = module.params.get('values')
+
+    # Retrieve any AWS settings from the environment.
+    region, ec2_url, aws_connect_kwargs = get_aws_connection_info(module, boto3=True)
+    if not region:
+        module.fail_json(msg="Either region or AWS_REGION or EC2_REGION environment variable or boto config aws_region or ec2_region must be set.")
+
+    connection = boto3_conn(module, conn_type='client',
+                            resource='elasticache', region=region,
+                            endpoint=ec2_url, **aws_connect_kwargs)
+
+    exists = get_info(connection, parameter_group_name)
+
+    # check that the needed requirements are available
+    if state == 'present' and not exists and not (parameter_group_family or group_description):
+        module.fail_json(msg="Creating a group requires a family group and a description.")
+    elif state == 'reset' and not exists:
+        module.fail_json(msg="No group %s to reset. Please create the group before using the state 'reset'." % parameter_group_name)
+
+    # Taking action
+    changed = False
+    if state == 'present':
+        if exists:
+            # confirm that the group exists without any actions
+            if not values:
+                response = exists
+                changed = False
+            # modify existing group
+            else:
+                modifiable_params = make_current_modifiable_param_dict(module, connection, parameter_group_name)
+                changed = check_valid_modification(module, values, modifiable_params)
+                response = modify(module, connection, parameter_group_name, values)
+        # create group
+        else:
+            response, changed = create(module, connection, parameter_group_name, parameter_group_family, group_description)
+            if values:
+                modifiable_params = make_current_modifiable_param_dict(module, connection, parameter_group_name)
+                changed = check_valid_modification(module, values, modifiable_params)
+                response = modify(module, connection, parameter_group_name, values)
+    elif state == 'absent':
+        if exists:
+            # delete group
+            response, changed = delete(module, connection, parameter_group_name)
+        else:
+            response = {}
+            changed = False
+    elif state == 'reset':
+        response, changed = reset(module, connection, parameter_group_name, values)
+
+    facts_result = dict(changed=changed, elasticache=camel_dict_to_snake_dict(response))
+
+    module.exit_json(**facts_result)
+
+if __name__ == '__main__':
+    main()