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
```
pattern = 'arn:aws:states:%s:%s:stateMachine:%s'
    return _resource_arn(name, pattern, account_id=account_id, region_name=region_name)
def stepfunctions_activity_arn(name, account_id=None, region_name=None):
    pattern = 'arn:aws:states:%s:%s:activity:%s'
    return _resource_arn(name, pattern, account_id=account_id, region_name=region_name)
def fix_arn(arn):
    """ Function that attempts to "canonicalize" the given ARN. This includes converting
        resource names to ARNs, replacing incorrect regions, account IDs, etc. """
    if arn.startswith('arn:aws:lambda'):
        parts = arn.split(':')
        region = parts[3] if parts[3] in config.VALID_REGIONS else get_region()
        return lambda_function_arn(lambda_function_name(arn), region_name=region)
    LOG.warning('Unable to fix/canonicalize ARN: %s' % arn)
    return arn
def cognito_user_pool_arn(user_pool_id, account_id=None, region_name=None):
    pattern = 'arn:aws:cognito-idp:%s:%s:userpool/%s'
    return _resource_arn(user_pool_id, pattern, account_id=account_id, region_name=region_name)
def kinesis_stream_arn(stream_name, account_id=None):
    account_id = get_account_id(account_id)
    return 'arn:aws:kinesis:%s:%s:stream/%s' % (get_region(), account_id, stream_name)
def firehose_stream_arn(stream_name, account_id=None):