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
```
bucket_name = normalize_bucket_name(bucket_name)
    response = Response()
    exists, code = bucket_exists(bucket_name)
    if not exists:
        response.status_code = code
        return response
    if not isinstance(cors, dict):
        cors = xmltodict.parse(cors)
    BUCKET_CORS[bucket_name] = cors
    response.status_code = 200
    return response
def delete_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
    BUCKET_CORS.pop(bucket_name, {})
    response.status_code = 200
    return response
def append_cors_headers(bucket_name, request_method, request_headers, response):