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
```
elif mapped.startswith(occurred):
        suffix = mapped[len(occurred):]
        return suffix[0] == '/'
    else:
        return False
def get_function_version(arn, version):
    func = arn_to_lambda.get(arn)
    return format_func_details(func, version=version, always_add_version=True)
def publish_new_function_version(arn):
    func_details = arn_to_lambda.get(arn)
    versions = func_details.versions
    last_version = func_details.max_version()
    versions[str(last_version + 1)] = {
        'CodeSize': versions.get('$LATEST').get('CodeSize'),
        'CodeSha256': versions.get('$LATEST').get('CodeSha256'),
        'Function': versions.get('$LATEST').get('Function'),
        'RevisionId': str(uuid.uuid4())
    }
    return get_function_version(arn, str(last_version + 1))
def do_list_versions(arn):
    return sorted([get_function_version(arn, version) for version in
                   arn_to_lambda.get(arn).versions.keys()], key=lambda k: str(k.get('Version')))
def do_update_alias(arn, alias, version, description=None):
    new_alias = {
        'AliasArn': arn + ':' + alias,
        'FunctionVersion': version,
        'Name': alias,
        'Description': description or '',
        'RevisionId': str(uuid.uuid4())