sqs.changeMessageVisibility according to [this](https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_ChangeMessageVisibility.html#API_ChangeMessageVisibility_Examples) makes a request directly to the Queue's URL rather than via the SQS Endpoint. (I'm already setting SQS endpoint to LOCALSTACK_HOSTNAME - makes no difference for this call)..

In localstack the queue URL host returned is by default set to the value of HOSTNAME_EXTERNAL, which I'm setting to localstack, but calling this method within a lambda, does not work and I get the error:

```
UnknownEndpoint: Inaccessible host: `localstack'. This service may not be available in the `us-east-1' region. 
```

So, how can I make the queue URL accessible from within a lambda using localstack? Effectively I need to make **http://localstack** accessible from within lambda.

I'm using the following cmd to start localstack:

```
LAMBDA_EXECUTOR=docker-reuse DEBUG=1 LAMBDA_REMOTE_DOCKER=0 DATA_DIR=/tmp/localstack/data HOSTNAME_EXTERNAL=localstack localstack start
```
if lambda_function_config:
        
        connection_config = botocore.config.Config(read_timeout=300)
        lambda_client = aws_stack.connect_to_service('lambda', config=connection_config)
        try:
            lambda_client.invoke(FunctionName=lambda_function_config,
                                 InvocationType='Event', Payload=message)
        except Exception:
            LOGGER.warning('Unable to send notification for S3 bucket "%s" to Lambda function "%s".' %
                (bucket_name, lambda_function_config))
    if not filter(lambda x: notif.get(x), NOTIFICATION_DESTINATION_TYPES):
        LOGGER.warning('Neither of %s defined for S3 notification.' %
            '/'.join(NOTIFICATION_DESTINATION_TYPES))
def get_cors(bucket_name):
    bucket_name = normalize_bucket_name(bucket_name)
    response = Response()
    exists, code = bucket_exists(bucket_name)
    if not exists:
        response.status_code = code
        return response
    cors = BUCKET_CORS.get(bucket_name)
    if not cors:
        cors = {
            'CORSConfiguration': []
        }
    body = xmltodict.unparse(cors)
    response._content = body
    response.status_code = 200
    return response
def set_cors(bucket_name, cors):