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
```
super(LambdaExecutorReuseContainers, self).__init__()
        
        self.docker_container_lock = threading.RLock()
        
        
        
        
        self.next_port = 0
        self.max_port = LAMBDA_SERVER_UNIQUE_PORTS
        self.port_offset = LAMBDA_SERVER_PORT_OFFSET
    def prepare_execution(self, func_arn, env_vars, runtime, command, handler, lambda_cwd):
        
        has_been_invoked_before = func_arn in self.function_invoke_times
        
        with self.docker_container_lock:
            env_vars['_LAMBDA_SERVER_PORT'] = str(self.next_port + self.port_offset)