docker-compose up 找不到其他容器主机

Question

由于未知原因，今天早上我尝试在我的项目中运行docker-compose up时遇到了 docker 错误。

我的 web 容器无法连接到数据库主机并且nc仍然返回

web_1 | nc: 错误地址 'db'

我的 docker-compose 定义中有相关部分：

version: '3.2'

services:
  web:
    build: ./app
    command: python manage.py runserver 0.0.0.0:8000
    volumes:
      - ./app/:/usr/src/app/
    ports:
      - 8000:8000
    env_file:
      - ./.env.dev
    depends_on:
      - db
  db:
    image: postgres:12.0-alpine
    volumes:
      - postgres_data:/var/lib/postgresql/data/
    environment:
      - POSTGRES_USER=
      - POSTGRES_PASSWORD=
      - POSTGRES_DB=
  mailhog:
     # mailhog declaration
volumes:
  postgres_data:

我怀疑网络坏了，实际上是。 这是我检查与该项目相关的 docker 网络时得到的结果：（ docker network inspect my_docker_network ）

[
    {
        "Name": "my_docker_network",
        "Id": "f09c148d9f3253d999e276c8b1061314e5d3e1f305f6124666e2e32a8e0d9efd",
        "Created": "2020-11-18T13:30:29.710456682-05:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.19.0.0/16",
                    "Gateway": "172.19.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": true,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {}, // <=== This is empty !
        "Options": {},
        "Labels": {
            "com.docker.compose.network": "default",
            "com.docker.compose.project": "my-project"
        }
    }
]

版本：

Docker：18.09.1，构建 4c52b90

Docker-compose：1.21.0，构建未知

Answer 1

我可以通过运行docker-compose down && docker-compose up来解决这个问题，但如果你的 down 正在删除所有卷，那么你的数据可能会有点糟糕......

联网检查现在可以了：

[
    {
        "Name": "my_docker_network",
        "Id": "236c45042b03c3a2922d9a9fabf644048901c66b3c1fd15507aca2c464c1d7ef",
        "Created": "2020-12-04T12:04:40.765889533-05:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.19.0.0/16",
                    "Gateway": "172.19.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": true,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "0939787203f2e222f2db380e8d5b36928e95bc7242c58df56b3e6e419efdd280": {
                "Name": "my_docker_db_1",
                "EndpointID": "af206a7e957682d3d9aee2ec0ffae2c51638cbe8821d3b20eb786165a0159c9d",
                "MacAddress": "02:42:ac:13:00:02",
                "IPv4Address": "172.19.0.2/16",
                "IPv6Address": ""
            },
            "ae90bd27539e89d0b26e0768aec765431ee623f45856e13797f3ba0262cca3f2": {
                "Name": "my_docker_web_1",
                "EndpointID": "09b5cefed6c5b49d31497419fd5784dcd887a23875e6c998209615c7ec8863f4",
                "MacAddress": "02:42:ac:13:00:04",
                "IPv4Address": "172.19.0.4/16",
                "IPv6Address": ""
            },
            "f2d3e46ab544b146bdc0aafba9fddb4e6c9d9ffd02c2015627516c7d6ff17567": {
                "Name": "my_docker_mailhog_1",
                "EndpointID": "242a693e6752f05985c377cd7c30f6781f0576bcd5ffede98f77f82efff8c78f",
                "MacAddress": "02:42:ac:13:00:03",
                "IPv4Address": "172.19.0.3/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {
            "com.docker.compose.network": "default",
            "com.docker.compose.project": "my_docker_project"
        }
    }
]

但是：是否有人知道发生了什么以及如何防止此问题再次出现？

Answer 2

我遇到了同样的问题，但是在我的撰写文件中使用了 rabbitmq 服务。 起初我通过删除机器上所有现有的容器和卷来解决它，但后来我将 rabbitmq 映像版本更新为docker-compose.yml中的最新版本：

image: rabbitmq:latest

然后问题并没有再次出现......