错误：撰写文件 docker-compose.yml 无效

Question

version: '3.7'
services:
  docker-mongo:
   image:
     - mongo:4.2.1
   ports:
     - "27017:27017"
   networks:
     - mynetwork


networks:
  mynetwork:

当我执行docker-compose config ，出现以下错误：

Version in "./docker-compose.yml" is unsupported. You might be seeing this error because you're using the wrong Compose file version. Either specify a supported version (e.g "2.2" or "3.3") and place your service definitions under the `services` key, or omit the `version` key and place your service definitions at the root of the file to use version 1.
For more on the Compose file format versions, see https://docs.docker.com/compose/compose-file/

因此，根据我尝试使用2.2和3.3版的错误消息，两者都导致相同的错误消息

ERROR: The Compose file './docker-compose.yml' is invalid because:
services.docker-mongo.image contains an invalid type, it should be a string

• Ubuntu 18.04.2 LTS
• Docker 版本 18.09.6，构建 481bc77
• docker-compose 版本 1.17.1，构建未知

Answer 1

错误消息是自我解释的，您的 docker-compose 应如下所示：

version: '3.7'
services:
  docker-mongo:
   image: mongo:4.2.1
   ports:
     - "27017:27017"
   networks:
     - mynetwork


networks:
  mynetwork: