It looks like a duplicate of old issue https://github.com/localstack/localstack/issues/78
But now it's reproducible for me with the latest version of LocalStack. 
try:
        with open(os.devnull, 'w') as devnull:
            subprocess.check_output('docker ps', stderr=devnull, shell=True)
        return True
    except Exception:
        return False
def is_linux():
    try:
        out = subprocess.check_output('uname -a', shell=True)
        out = out.decode('utf-8') if isinstance(out, six.binary_type) else out
        return 'Linux' in out
    except subprocess.CalledProcessError:
        return False
LAMBDA_EXECUTOR = os.environ.get('LAMBDA_EXECUTOR', '').strip()
if not LAMBDA_EXECUTOR:
    LAMBDA_EXECUTOR = 'docker'
    if not has_docker():
        LAMBDA_EXECUTOR = 'local'
LAMBDA_FALLBACK_URL = os.environ.get('LAMBDA_FALLBACK_URL', '').strip()
CONFIG_ENV_VARS = ['SERVICES', 'HOSTNAME', 'HOSTNAME_EXTERNAL', 'LOCALSTACK_HOSTNAME', 'LAMBDA_FALLBACK_URL',
                   'LAMBDA_EXECUTOR', 'LAMBDA_REMOTE_DOCKER', 'LAMBDA_DOCKER_NETWORK', 'USE_SSL', 'DEBUG',
                   'KINESIS_ERROR_PROBABILITY', 'DYNAMODB_ERROR_PROBABILITY', 'PORT_WEB_UI', 'START_WEB',
                   'DOCKER_BRIDGE_IP', 'DEFAULT_REGION', 'LAMBDA_JAVA_OPTS', 'LOCALSTACK_API_KEY',
                   'LAMBDA_CONTAINER_REGISTRY', 'TEST_AWS_ACCOUNT_ID']
for key, value in six.iteritems(DEFAULT_SERVICE_PORTS):
    clean_key = key.upper().replace('-', '_')
    CONFIG_ENV_VARS += [clean_key + '_BACKEND', clean_key + '_PORT', clean_key + '_PORT_EXTERNAL']
def ping(host):