web_manage_aws_services_easy.py

web_manage_aws_services_easy.py

import json
import boto3

def lambda_handler(event, context):
    msg = None

    try:
        
        data = json.loads(event['body'].lower())
        
        # Manage EC2 instances.
        if data['service'] == 'ec2':
            client = boto3.client('ec2')

            # Get instance list from names.
            if ('items' not in data) or (len(data['items']) < 1):
                raise Exception('No items specified!')
            response = client.describe_instances(
                Filters=[{'Name': 'tag:Name', 'Values': data['items']}]
            )
            instances = [
                instance['InstanceId'] 
                for reservation in response['Reservations']
                for instance in reservation['Instances']
            ]
            if not instances:
                raise Exception('No instances found matching specified names!')
            
            # Execute actions.
            if data['action'] == 'start':
                client.start_instances(InstanceIds=instances)
                msg = f'Successfully started instances.'
            elif data['action'] == 'stop':
                client.stop_instances(InstanceIds=instances)
                msg = f'Successfully stopped instances.'
            elif data['action'] == 'reboot':
                client.reboot_instances(InstanceIds=instances)
                msg = f'Successfully rebooted instances.'
            else:
                raise Exception(f'Specified action "{data["action"]}" unknown!')

        # Manage Route53.
        elif data['service'] == 'route53':
            if data['action'] != 'upsert':
                raise Exception(f'Specified action "{data["action"]}" unknown!')

            # Extract parameters.
            if ('items' not in data) or (len(data['items']) != 1):
                raise Exception('Invalid items specified!')
            tmp1 = data['items'][0].split('>')
            if len(tmp1) != 2:
                raise Exception('Invalid action item specified!')
            tmp2 = tmp1[0].split('.')
            if len(tmp2) != 3:
                raise Exception('Invalid domain specified!')
            subdomain = tmp2[0]
            domain = '.'.join(tmp2[1:])
            tmp2 = tmp1[1].split('.')
            if len(tmp2) != 4:
                raise Exception('Invalid IP specified!')
            ip = tmp1[1]

            client = boto3.client('route53')

            # Get hosted zone ID from name.
            response = client.list_hosted_zones_by_name(DNSName=domain)
            zone_id = None
            hosted_zones = response['HostedZones']
            for zone in hosted_zones:
                if zone['Name'] == domain + ".":
                    zone_id = zone['Id'].split('/')[-1]
            if zone_id is None:
                raise Exception('No hosted zone found matching specified name!')

            # Create DNS change.
            change_batch = {
                'Comment': 'upsert via lambda',
                'Changes': [
                    {
                        'Action': 'UPSERT',
                        'ResourceRecordSet': {
                            'Name': subdomain + '.' + domain + '.',
                            'Type': 'A',
                            'TTL': 60,
                            'ResourceRecords': [{'Value': ip}]
                        }
                    }
                ]
            }
            response = client.change_resource_record_sets(
                HostedZoneId=zone_id,
                ChangeBatch=change_batch
            )
            msg = "Successfully updated DNS."
   

        # Manage CloudFront.
        elif data['service'] == 'cloudfront':
            if data['action'] != 'refresh':
                raise Exception(f'Specified action "{data["action"]}" unknown!')

            client = boto3.client('cloudfront')

            # Get the distribution ID by description.
            if ('items' not in data) or (len(data['items']) != 1):
                raise Exception('Invalid items specified!')
            distributions = client.list_distributions()
            distribution_id = None
            if 'DistributionList' in distributions and distributions['DistributionList']['Quantity'] > 0:
                for distribution in distributions['DistributionList']['Items']:
                    if distribution.get('Comment') == data['items'][0]:
                        distribution_id = distribution['Id']
                        break
            if distribution_id is None:
                raise Exception('No distribution found matching specified name!')

            # Create the invalidation
            response = client.create_invalidation(
                DistributionId=distribution_id,
                InvalidationBatch={
                    'Paths': {
                        'Quantity': 1,
                        'Items': ['/*']  # Invalidating all files
                    },
                    'CallerReference': str(hash('/*'))
                }
            )
            msg = "Successfully refreshed distribution."

        else:
            raise Exception(f'Specified service "{data["service"]}" unknown!')
        
        # Send success message.
        if msg is not None:
            return {
                'statusCode': 200,
                'body': msg
            }
        else:
            raise Exception('Unknown error!')

    # Send error message.
    except Exception as e:
        return {
            'statusCode': 400,
            'body': str(e)
        }