Sometimes, attempting to run lambdas will return this type of error:
```
{"Type": "Server", "message": "Error executing Lambda function arn:aws:lambda:ap-northeast-1:000000000000:function:service-stage-functionName: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists Traceback (most recent call last):\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_api.py\", line 338, in run_lambda\n 
event, context=context, version=version, asynchronous=asynchronous)\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 81, in execute\n 
return do_execute()\n File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 70, in do_execute\n self._store_logs(func_details, log_output, invocation_time)\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 105, in _store_logs\n logs_client.create_log_group(logGroupName=log_group_name)\n 
File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 357, in _api_call\n 
return self._make_api_call(operation_name, kwargs)\n 
File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 661, in _make_api_call\n 
raise error_class(parsed_response, operation_name)\n
botocore.errorfactory.ResourceAlreadyExistsException: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists\n", "__type": "InternalFailure"}
```
I am not yet sure if there are any particular settings that cause it, since it does not occur for certain deployments.

Will update if I can figure out the exact configuration.
:return: A String[] localstack docker container names for each function.
        """
        with self.docker_container_lock:
            LOG.debug('Getting all lambda containers names.')
            cmd = '%s ps -a --filter="name=localstack_lambda_*" --format "{{.Names}}"' % self._docker_cmd()
            LOG.debug(cmd)
            cmd_result = run(cmd, asynchronous=False, stderr=subprocess.PIPE, outfile=subprocess.PIPE).strip()
            if len(cmd_result) > 0:
                container_names = cmd_result.split('\n')
            else:
                container_names = []
            return container_names
    def destroy_existing_docker_containers(self):
        """
        Stops and/or removes all lambda docker containers for localstack.
        :return: None
        """
        with self.docker_container_lock:
            container_names = self.get_all_container_names()
            LOG.debug('Removing %d containers.' % len(container_names))
            for container_name in container_names:
                cmd = '%s rm -f %s' % (self._docker_cmd(), container_name)
                LOG.debug(cmd)
                run(cmd, asynchronous=False, stderr=subprocess.PIPE, outfile=subprocess.PIPE)
    def get_docker_container_status(self, func_arn):
        """
        Determine the status of a docker container.
        :param func_arn: The ARN of the lambda function.
        :return: 1 If the container is running,
        -1 if the container exists but is not running