Add lambda_event module

1 files changed, 422 insertions, 0 deletions

diff --git a/cloud/amazon/lambda_event.py b/cloud/amazon/lambda_event.py
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+++ b/cloud/amazon/lambda_event.py
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+#!/usr/bin/python
+# (c) 2016, Pierre Jodouin <pjodouin@virtualcomputing.solutions>
+#
+# 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/>.
+
+import sys
+
+try:
+    import boto3
+    from botocore.exceptions import ClientError, ParamValidationError, MissingParametersError
+    HAS_BOTO3 = True
+except ImportError:
+    HAS_BOTO3 = False
+
+
+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.
+    required: false
+    default: stream
+    choices: ['stream']
+  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.
+    required: true
+requirements:
+    - boto3
+extends_documentation_fragment:
+    - aws
+
+'''
+
+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
+'''
+
+# ---------------------------------------------------------------------------------------------------
+#
+#   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('^[\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:
+        module.fail_json(msg='Function name "{0}" exceeds 64 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)
+            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"]
+
+    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=True, 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)
+
+    this_module_function = getattr(this_module, 'lambda_event_{}'.format(module.params['event_source'].lower()))
+
+    results = this_module_function(module, aws)
+
+    module.exit_json(**results)
+
+
+# ansible import module(s) kept at ~eof as recommended
+from ansible.module_utils.basic import *
+from ansible.module_utils.ec2 import *
+
+if __name__ == '__main__':
+    main()