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
```
lambda_client.create_event_source_mapping(EventSourceArn=queue_arn2, FunctionName=lambda_name)
        
        payload = {
            lambda_integration.MSG_BODY_RAISE_ERROR_FLAG: 1
        }
        self.client.send_message(QueueUrl=queue_url2, MessageBody=json.dumps(payload))
        
        def receive_dlq():
            result = self.client.receive_message(QueueUrl=queue_url1, MessageAttributeNames=['All'])
            self.assertGreater(len(result['Messages']), 0)
            msg_attrs = result['Messages'][0]['MessageAttributes']
            self.assertIn('RequestID', msg_attrs)
            self.assertIn('ErrorCode', msg_attrs)
            self.assertIn('ErrorMessage', msg_attrs)
        retry(receive_dlq, retries=8, sleep=2)
    def test_set_queue_attribute_at_creation(self):
        queue_name = 'queue-%s' % short_uid()
        attributes = {
            'MessageRetentionPeriod': '604800',  
            'ReceiveMessageWaitTimeSeconds': '10',
            'VisibilityTimeout': '30'
        }
        queue_url = self.client.create_queue(QueueName=queue_name, Attributes=attributes)['QueueUrl']
        creation_attributes = self.client.get_queue_attributes(QueueUrl=queue_url, AttributeNames=['All'])
        
        self.assertIn('MessageRetentionPeriod', creation_attributes['Attributes'].keys())
        self.assertEqual('604800', creation_attributes['Attributes']['MessageRetentionPeriod'])
        
        self.client.delete_queue(QueueUrl=queue_url)
    def test_get_specific_queue_attribute_response(self):