def agent_creator()

in source/CRRdeployagent/CRRdeployagent.py [0:0]
110 lines of code
12 McCabe index (conditional complexity)

def agent_creator(agt_region, topic_name, queue_arn, monitor_account, agent_accounts):

    rule = 'CRRRemoteAgent'

    if not monitor_account:
        rule = 'CRRAgent'

    boto3.setup_default_session(region_name=agt_region)
    # -----------------------------------------------------------------
    # Create client connections
    #
    try:
        cwe = boto3.client('events')
        sns = boto3.client('sns')
    except Exception as e:
        print(e)
        print('Error creating clients for ' + agt_region)
        raise e

    try:
        cwe.put_rule(
            Description='Fires CRRMonitor for S3 events that indicate an object has been stored.',
            Name=rule,
            EventPattern="{ \"detail-type\": [ \"AWS API Call via CloudTrail\" ], \"detail\": { \"eventSource\": [ \"s3.amazonaws.com\"], \"eventName\": [ \"PutObject\", \"CopyObject\", \"CompleteMultipartUpload\" ] } }",
            State='DISABLED'
        )
    except Exception as e:
        print(e)
        print('Error creating CW Event rule')
        raise e

    if not monitor_account:
        print('Creating agent for a monitor/agent account in region ' + agt_region)
        topic = topic_name + "-" + agt_region

        # -----------------------------------------------------------------
        # Note: duplication is not a concern - we will replace the rule and
        # topic if they already exist
        #
        # Create the CloudWatch Event rule in a disabled state.
        # Create an SNS topic
        # Add a target to the rule to send to the new SNS topic
        # Enable the rule
        try:

            topicarn = sns.create_topic(Name=topic)['TopicArn']
            sns.set_topic_attributes(
                TopicArn=topicarn,
                AttributeName='Policy',
                AttributeValue='{\
            "Version": "2012-10-17",\
            "Id": "CWEventPublishtoTopic",\
            "Statement": [\
                {\
                  "Sid": "CWEventPublishPolicy",\
                  "Action": [\
                    "SNS:Publish"\
                  ],\
                  "Effect": "Allow",\
                  "Resource": "' + topicarn + '",\
                  "Principal": {\
                    "Service": [\
                      "events.amazonaws.com"\
                    ]\
                  }\
                }\
              ]\
            }\
                    ',

            )
            cwe.put_targets(
                Rule=rule,
                Targets=[
                    {
                        'Id': 'CRRAgent-' + agt_region,
                        'Arn': topicarn
                    }
                ]
            )
            cwe.enable_rule(Name=rule)
        except Exception as e:
            print(e)
            print('Error creating SNS topic and CW Event rule: ' + topic)
            raise e

        # -----------------------------------------------------------------
        # Create cross-region Queue subscription from the SNS end
        # Only when deployed from the Manager account
        #
        try:
            response = sns.subscribe(
                TopicArn=topicarn,
                Protocol='sqs',
                Endpoint=queue_arn
            )

        except Exception as e:
            print(e)
            print('Error subscribing SNS topic ' + topic + ' to SQS Queue ' + queue_arn)
            raise e

        # Grant permissions to the default event bus
        for account in agent_accounts:
            try:
                cwe.put_permission(
                    Action='events:PutEvents',
                    Principal=account,
                    StatementId=account
                )
            except Exception as e:
                print(e)
                print('Error creating Event Bus permissions for ' + account)
                raise e

        return_data = {
            'Data': { 'TopicArn': topicarn },
            'PhysicalResourceId': 'CRRMonitorAgent-' + agt_region
            }

    else:
        print('Creating agent for an agent-only account in region ' + agt_region)
        try:
            cwe.put_targets(
                Rule=rule,
                Targets=[
                    {
                        'Id': 'CRRRemoteAgent-' + agt_region,
                        'Arn': 'arn:aws:events:' + agt_region + ':' + monitor_account + ':event-bus/default'
                    }
                ]
            )
            cwe.enable_rule(Name=rule)
        except Exception as e:
            print(e)
            print('Error creating CW Event target')
            raise e

        return_data = {'PhysicalResourceId': 'CRRMonitorAgent-' + agt_region}

    return return_data