The lambda execution is not suspending and the lambda container has no port exposed when running a java 11 lambda with the latest localstack docker image by docker-compose with the environment variable LAMBDA_JAVA_OPTS=-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=_debug_port_
    
It works fine for java8 runtime executions.

Docker command:

> localstack_1  | 2020-01-26T12:42:04:INFO:localstack.services.awslambda.lambda_executors: Running lambda cmd: CONTAINER_ID="$(docker create -i   -e ENV="$ENV" -e DOCKER_LAMBDA_USE_STDIN="$DOCKER_LAMBDA_USE_STDIN" -e HOSTNAME="$HOSTNAME" -e LOCALSTACK_HOSTNAME="$LOCALSTACK_HOSTNAME" -e AWS_LAMBDA_FUNCTION_TIMEOUT="$AWS_LAMBDA_FUNCTION_TIMEOUT" -e AWS_LAMBDA_FUNCTION_NAME="$AWS_LAMBDA_FUNCTION_NAME" -e AWS_LAMBDA_FUNCTION_VERSION="$AWS_LAMBDA_FUNCTION_VERSION" -e AWS_LAMBDA_FUNCTION_INVOKED_ARN="$AWS_LAMBDA_FUNCTION_INVOKED_ARN"  --rm "lambci/lambda:java11" "com.XXX.XXX.Handler")";docker cp "/tmp/localstack/zipfile.0c90736c/." "$CONTAINER_ID:/var/task"; docker start -ai "$CONTAINER_ID";

I think this is due to the fact that the classpath arguments and java opts are only being set if the rutime is equal to LAMBDA_RUNTIME_JAVA8 (line 211 of ocalstack/localstack/services/awslambda/lambda_executors.py , commit 03c6f4bf250edd18eb818ed65090f508636b0bff)
os.chdir(lambda_cwd)
            if environment:
                os.environ.update(environment)
            result = lambda_function(event, context)
            queue.put(result)
        process = Process(target=do_execute)
        with CaptureOutput() as c:
            process.run()
        result = queue.get()
        
        log_output = ''
        for stream in (c.stdout(), c.stderr()):
            if stream:
                log_output += ('\n' if log_output else '') + stream
        return result, log_output
    def execute_java_lambda(self, event, context, handler, main_file):
        event_file = EVENT_FILE_PATTERN.replace('*', short_uid())
        save_file(event_file, json.dumps(event))
        TMP_FILES.append(event_file)
        class_name = handler.split('::')[0]
        classpath = '%s:%s:%s' % (LAMBDA_EXECUTOR_JAR, main_file, Util.get_java_classpath(main_file))
        cmd = 'java -cp %s %s %s %s' % (classpath, LAMBDA_EXECUTOR_CLASS, class_name, event_file)
        result, log_output = self.run_lambda_executor(cmd)
        LOG.debug('Lambda result / log output:\n%s\n> %s' % (
            result.strip(), log_output.strip().replace('\n', '\n> ')))
        return result, log_output
class Util:
    debug_java_port = False
    @classmethod
    def get_java_opts(cls):