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 not msg:
        msg = 'The resource you requested does not exist.'
        if ref:
            msg = '%s not found: %s' % ('Function' if ':function:' in ref else 'Resource', ref)
    return error_response(msg, 404, error_type='ResourceNotFoundException')
@app.before_request
def before_request():
    
    transfer_encoding = request.headers.get('Transfer-Encoding', '').lower()
    if transfer_encoding == 'chunked':
        request.environ['wsgi.input_terminated'] = True
@app.route('%s/functions' % PATH_ROOT, methods=['POST'])
def create_function():
    """ Create new function
        ---
        operationId: 'createFunction'
        parameters:
            - name: 'request'
              in: body
    """
    arn = 'n/a'
    try:
        data = json.loads(to_str(request.data))
        lambda_name = data['FunctionName']
        event_publisher.fire_event(event_publisher.EVENT_LAMBDA_CREATE_FUNC,
            payload={'n': event_publisher.get_hash(lambda_name)})