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_cwd:
            previous_cwd = os.getcwd()
            os.chdir(lambda_cwd)
            sys.path = [lambda_cwd] + sys.path
        if lambda_env:
            previous_env = dict(os.environ)
            os.environ.update(lambda_env)
    
    lambda_id = 'l_%s' % short_uid()
    lambda_file = LAMBDA_SCRIPT_PATTERN.replace('*', lambda_id)
    save_file(lambda_file, script)
    
    TMP_FILES.append(lambda_file)
    TMP_FILES.append('%sc' % lambda_file)
    try:
        handler_module = imp.load_source(lambda_id, lambda_file)
        module_vars = handler_module.__dict__
    except Exception as e:
        LOG.error('Unable to exec: %s %s' % (script, traceback.format_exc()))
        raise e
    finally:
        if lambda_cwd or lambda_env:
            if lambda_cwd:
                os.chdir(previous_cwd)
                sys.path.pop(0)
            if lambda_env:
                os.environ = previous_env
            exec_mutex.release()
    return module_vars[handler_function]
def get_handler_file_from_name(handler_name, runtime=LAMBDA_DEFAULT_RUNTIME):