migrate.py

def migrate(instances_list):
    # create boto3 client for ec2 for both source and destination region
    client_src = boto3.client('ec2', region_name=os.getenv('SOURCE_REGION'))
    client_des = boto3.client('ec2', region_name=os.getenv('DESTINATION_REGION'))
    # create ec2 resource
    ec2 = boto3.resource('ec2', region_name=os.getenv('DESTINATION_REGION'))
    total_instances = len(instances_list)
    # iterate through list of intances in source region to be migrated
    for n, instance in enumerate(instances_list):
        try:
            print(str(n+1) + '/' + str(total_instances) + ': ' + instance)
            # stop the source instance first, not mandatory but recommended, inorder to keep instance's integrity
            stop_instance(instance_id=instance, client=client_src)
            # create image of the source instance
            image_id_src = create_image_of_instance(instance_id=instance, client=client_src)
            print('Source image_id: ' + image_id_src)
            # copy the image from source region to destination region (destination client is needed for this function)
            image_id_des = copy_image_to_destination_region(image_id=image_id_src, instance_id=instance, client=client_des)
            print('Destination image_id: ' + image_id_des)
            result = launch_instance(
                image_id=image_id_des,
                instance_id=instance,
                client_src=client_src,
                client_des=client_des,
                ec2_resource_des=ec2
            )
            if result['success']:
                print('Migration of instance: ' + instance + ' completed successfully')
            else:
                print('Migration of instance: ' + instance + ' failed due to error: ' + result['error_msg'])
        except Exception as e: 
            print('Migration of instance: ' + instance + ' failed due to error: ' + str(e))