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
```
result.update(format_func_details(func_details))
    if isinstance(result, Response):
        return result
    return jsonify(result or {})
@app.route('%s/functions/<function>/code' % PATH_ROOT, methods=['GET'])
def get_function_code(function):
    """ Get the code of an existing function
        ---
        operationId: 'getFunctionCode'
        parameters:
    """
    arn = func_arn(function)
    lambda_cwd = arn_to_lambda[arn].cwd
    tmp_file = '%s/%s' % (lambda_cwd, LAMBDA_ZIP_FILE_NAME)
    return Response(load_file(tmp_file, mode='rb'),
            mimetype='application/zip',
            headers={'Content-Disposition': 'attachment; filename=lambda_archive.zip'})
@app.route('%s/functions/<function>/configuration' % PATH_ROOT, methods=['GET'])
def get_function_configuration(function):
    """ Get the configuration of an existing function
        ---
        operationId: 'getFunctionConfiguration'
        parameters:
    """
    arn = func_arn(function)
    lambda_details = arn_to_lambda.get(arn)
    if not lambda_details:
        return not_found_error(arn)
    result = format_func_details(lambda_details)
    return jsonify(result)