#!/usr/bin/python # (c) 2016, Pierre Jodouin # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt) from __future__ import absolute_import, division, print_function __metaclass__ = type ANSIBLE_METADATA = {'metadata_version': '1.1', 'status': ['preview'], 'supported_by': 'community'} DOCUMENTATION = ''' --- module: lambda_event short_description: Creates, updates or deletes AWS Lambda function event mappings. description: - This module allows the management of AWS Lambda function event source mappings such as DynamoDB and Kinesis stream events via the Ansible framework. These event source mappings are relevant only in the AWS Lambda pull model, where AWS Lambda invokes the function. It is idempotent and supports "Check" mode. Use module M(lambda) to manage the lambda function itself and M(lambda_alias) to manage function aliases. version_added: "2.2" author: Pierre Jodouin (@pjodouin), Ryan Brown (@ryansb) options: lambda_function_arn: description: - The name or ARN of the lambda function. required: true aliases: ['function_name', 'function_arn'] state: description: - Describes the desired state. required: true default: "present" choices: ["present", "absent"] alias: description: - Name of the function alias. Mutually exclusive with C(version). required: true version: description: - Version of the Lambda function. Mutually exclusive with C(alias). required: false event_source: description: - Source of the event that triggers the lambda function. - For DynamoDB and Kinesis events, select 'stream' - For SQS queues, select 'sqs' required: false default: stream choices: ['stream', 'sqs'] source_params: description: - Sub-parameters required for event source. - I(== stream event source ==) - C(source_arn) The Amazon Resource Name (ARN) of the Kinesis or DynamoDB stream that is the event source. - C(enabled) Indicates whether AWS Lambda should begin polling the event source. Default is True. - C(batch_size) The largest number of records that AWS Lambda will retrieve from your event source at the time of invoking your function. Default is 100. - C(starting_position) The position in the stream where AWS Lambda should start reading. Choices are TRIM_HORIZON or LATEST. - I(== sqs event source ==) - C(source_arn) The Amazon Resource Name (ARN) of the SQS queue to read events from. - C(enabled) Indicates whether AWS Lambda should begin reading from the event source. Default is True. - C(batch_size) The largest number of records that AWS Lambda will retrieve from your event source at the time of invoking your function. Default is 100. required: true requirements: - boto3 extends_documentation_fragment: - aws - ec2 ''' EXAMPLES = ''' --- # Example that creates a lambda event notification for a DynamoDB stream - hosts: localhost gather_facts: no vars: state: present tasks: - name: DynamoDB stream event mapping lambda_event: state: "{{ state | default('present') }}" event_source: stream function_name: "{{ function_name }}" alias: Dev source_params: source_arn: arn:aws:dynamodb:us-east-1:123456789012:table/tableName/stream/2016-03-19T19:51:37.457 enabled: True batch_size: 100 starting_position: TRIM_HORIZON - name: Show source event debug: var: lambda_stream_events ''' RETURN = ''' --- lambda_stream_events: description: list of dictionaries returned by the API describing stream event mappings returned: success type: list ''' import re import sys try: import boto3 from botocore.exceptions import ClientError, ParamValidationError, MissingParametersError HAS_BOTO3 = True except ImportError: HAS_BOTO3 = False from ansible.module_utils.basic import AnsibleModule from ansible.module_utils.ec2 import (HAS_BOTO3, boto3_conn, camel_dict_to_snake_dict, ec2_argument_spec, get_aws_connection_info) # --------------------------------------------------------------------------------------------------- # # Helper Functions & classes # # --------------------------------------------------------------------------------------------------- class AWSConnection: """ Create the connection object and client objects as required. """ def __init__(self, ansible_obj, resources, use_boto3=True): try: self.region, self.endpoint, aws_connect_kwargs = get_aws_connection_info(ansible_obj, boto3=use_boto3) self.resource_client = dict() if not resources: resources = ['lambda'] resources.append('iam') for resource in resources: aws_connect_kwargs.update(dict(region=self.region, endpoint=self.endpoint, conn_type='client', resource=resource )) self.resource_client[resource] = boto3_conn(ansible_obj, **aws_connect_kwargs) # if region is not provided, then get default profile/session region if not self.region: self.region = self.resource_client['lambda'].meta.region_name except (ClientError, ParamValidationError, MissingParametersError) as e: ansible_obj.fail_json(msg="Unable to connect, authorize or access resource: {0}".format(e)) # set account ID try: self.account_id = self.resource_client['iam'].get_user()['User']['Arn'].split(':')[4] except (ClientError, ValueError, KeyError, IndexError): self.account_id = '' def client(self, resource='lambda'): return self.resource_client[resource] def pc(key): """ Changes python key into Pascale case equivalent. For example, 'this_function_name' becomes 'ThisFunctionName'. :param key: :return: """ return "".join([token.capitalize() for token in key.split('_')]) def ordered_obj(obj): """ Order object for comparison purposes :param obj: :return: """ if isinstance(obj, dict): return sorted((k, ordered_obj(v)) for k, v in obj.items()) if isinstance(obj, list): return sorted(ordered_obj(x) for x in obj) else: return obj def set_api_sub_params(params): """ Sets module sub-parameters to those expected by the boto3 API. :param params: :return: """ api_params = dict() for param in params.keys(): param_value = params.get(param, None) if param_value: api_params[pc(param)] = param_value return api_params def validate_params(module, aws): """ Performs basic parameter validation. :param module: :param aws: :return: """ function_name = module.params['lambda_function_arn'] # validate function name if not re.search(r'^[\w\-:]+$', function_name): module.fail_json( msg='Function name {0} is invalid. Names must contain only alphanumeric characters and hyphens.'.format(function_name) ) if len(function_name) > 64 and not function_name.startswith('arn:aws:lambda:'): module.fail_json(msg='Function name "{0}" exceeds 64 character limit'.format(function_name)) elif len(function_name) > 140 and function_name.startswith('arn:aws:lambda:'): module.fail_json(msg='ARN "{0}" exceeds 140 character limit'.format(function_name)) # check if 'function_name' needs to be expanded in full ARN format if not module.params['lambda_function_arn'].startswith('arn:aws:lambda:'): function_name = module.params['lambda_function_arn'] module.params['lambda_function_arn'] = 'arn:aws:lambda:{0}:{1}:function:{2}'.format(aws.region, aws.account_id, function_name) qualifier = get_qualifier(module) if qualifier: function_arn = module.params['lambda_function_arn'] module.params['lambda_function_arn'] = '{0}:{1}'.format(function_arn, qualifier) return def get_qualifier(module): """ Returns the function qualifier as a version or alias or None. :param module: :return: """ qualifier = None if module.params['version'] > 0: qualifier = str(module.params['version']) elif module.params['alias']: qualifier = str(module.params['alias']) return qualifier # --------------------------------------------------------------------------------------------------- # # Lambda Event Handlers # # This section defines a lambda_event_X function where X is an AWS service capable of initiating # the execution of a Lambda function (pull only). # # --------------------------------------------------------------------------------------------------- def lambda_event_stream(module, aws): """ Adds, updates or deletes lambda stream (DynamoDb, Kinesis) event notifications. :param module: :param aws: :return: """ client = aws.client('lambda') facts = dict() changed = False current_state = 'absent' state = module.params['state'] api_params = dict(FunctionName=module.params['lambda_function_arn']) # check if required sub-parameters are present and valid source_params = module.params['source_params'] source_arn = source_params.get('source_arn') if source_arn: api_params.update(EventSourceArn=source_arn) else: module.fail_json(msg="Source parameter 'source_arn' is required for stream event notification.") # check if optional sub-parameters are valid, if present batch_size = source_params.get('batch_size') if batch_size: try: source_params['batch_size'] = int(batch_size) except ValueError: module.fail_json(msg="Source parameter 'batch_size' must be an integer, found: {0}".format(source_params['batch_size'])) # optional boolean value needs special treatment as not present does not imply False source_param_enabled = module.boolean(source_params.get('enabled', 'True')) # check if event mapping exist try: facts = client.list_event_source_mappings(**api_params)['EventSourceMappings'] if facts: current_state = 'present' except ClientError as e: module.fail_json(msg='Error retrieving stream event notification configuration: {0}'.format(e)) if state == 'present': if current_state == 'absent': starting_position = source_params.get('starting_position') if starting_position: api_params.update(StartingPosition=starting_position) elif module.params.get('event_source') == 'sqs': # starting position is not required for SQS pass else: module.fail_json(msg="Source parameter 'starting_position' is required for stream event notification.") if source_arn: api_params.update(Enabled=source_param_enabled) if source_params.get('batch_size'): api_params.update(BatchSize=source_params.get('batch_size')) try: if not module.check_mode: facts = client.create_event_source_mapping(**api_params) changed = True except (ClientError, ParamValidationError, MissingParametersError) as e: module.fail_json(msg='Error creating stream source event mapping: {0}'.format(e)) else: # current_state is 'present' api_params = dict(FunctionName=module.params['lambda_function_arn']) current_mapping = facts[0] api_params.update(UUID=current_mapping['UUID']) mapping_changed = False # check if anything changed if source_params.get('batch_size') and source_params['batch_size'] != current_mapping['BatchSize']: api_params.update(BatchSize=source_params['batch_size']) mapping_changed = True if source_param_enabled is not None: if source_param_enabled: if current_mapping['State'] not in ('Enabled', 'Enabling'): api_params.update(Enabled=True) mapping_changed = True else: if current_mapping['State'] not in ('Disabled', 'Disabling'): api_params.update(Enabled=False) mapping_changed = True if mapping_changed: try: if not module.check_mode: facts = client.update_event_source_mapping(**api_params) changed = True except (ClientError, ParamValidationError, MissingParametersError) as e: module.fail_json(msg='Error updating stream source event mapping: {0}'.format(e)) else: if current_state == 'present': # remove the stream event mapping api_params = dict(UUID=facts[0]['UUID']) try: if not module.check_mode: facts = client.delete_event_source_mapping(**api_params) changed = True except (ClientError, ParamValidationError, MissingParametersError) as e: module.fail_json(msg='Error removing stream source event mapping: {0}'.format(e)) return camel_dict_to_snake_dict(dict(changed=changed, events=facts)) def main(): """Produce a list of function suffixes which handle lambda events.""" this_module = sys.modules[__name__] source_choices = ["stream", "sqs"] argument_spec = ec2_argument_spec() argument_spec.update( dict( state=dict(required=False, default='present', choices=['present', 'absent']), lambda_function_arn=dict(required=True, default=None, aliases=['function_name', 'function_arn']), event_source=dict(required=False, default="stream", choices=source_choices), source_params=dict(type='dict', required=True, default=None), alias=dict(required=False, default=None), version=dict(type='int', required=False, default=0), ) ) module = AnsibleModule( argument_spec=argument_spec, supports_check_mode=True, mutually_exclusive=[['alias', 'version']], required_together=[] ) # validate dependencies if not HAS_BOTO3: module.fail_json(msg='boto3 is required for this module.') aws = AWSConnection(module, ['lambda']) validate_params(module, aws) if module.params['event_source'].lower() in ('stream', 'sqs'): results = lambda_event_stream(module, aws) else: module.fail_json('Please select `stream` or `sqs` as the event type') module.exit_json(**results) if __name__ == '__main__': main()