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
```
auth_header = headers.get('Authorization')
    if not auth_header:
        return
    replaced = re.sub(r'(.*Credential=[^/]+/[^/]+/)([^/])+/', r'\1%s/' % get_region(), auth_header)
    headers['Authorization'] = replaced
def fix_account_id_in_arns(response, colon_delimiter=':', existing=None, replace=None):
    """ Fix the account ID in the ARNs returned in the given Flask response or string """
    existing = existing or ['123456789', '1234567890', MOTO_ACCOUNT_ID]
    existing = existing if isinstance(existing, list) else [existing]
    replace = replace or TEST_AWS_ACCOUNT_ID
    is_str_obj = is_string_or_bytes(response)
    content = to_str(response if is_str_obj else response._content)
    replace = r'arn{col}aws{col}\1{col}\2{col}{acc}{col}'.format(col=colon_delimiter, acc=replace)
    for acc_id in existing:
        regex = r'arn{col}aws{col}([^:%]+){col}([^:%]*){col}{acc}{col}'.format(col=colon_delimiter, acc=acc_id)
        content = re.sub(regex, replace, content)
    if not is_str_obj:
        response._content = content
        response.headers['content-length'] = len(response._content)
        return response
    return content
def get_s3_client():