node.js - Docker MongoDB收到元数据后立即关闭连接

Question

我试图用两个容器组成docker app:

mongo

应用程序

Mongo容器工作正常，而应用程序无法连接到mongo。 node.js应用程序和mongostat都不能。奇怪的是，我尝试在装有Win10的两台计算机上运行该项目，并且在另一台计算机上正常运行。

这些是当我从应用程序容器运行node app.js或mongostat --uri "mongodb://mongo:27017/project"时来自mongo容器的日志:

2019-05-22T09:33:52.225+0000 I NETWORK  [conn17] received client metadata from 192.168.96.2:42916 conn17: { driver: { name: "nodejs", version: "3.1.10" }, os: { type: "Linux", name: "linux", architecture: "x64", version: "4.9.125-linuxkit" }, platform: "Node.js v10.15.3, LE, mongodb-core: 3.1.9" }
2019-05-22T09:33:52.231+0000 I NETWORK  [conn17] end connection 192.168.96.2:42916 (0 connections now open)

这意味着两个容器都可以看到对方，因此.yml文件应该可以。如果问题出在代码上，那么它就不能同时在两台计算机上工作。

Dockerfile:

FROM node:10.15.3-alpine
RUN apk update && apk --no-cache --virtual build-dependencies add python make g++ && apk del build-dependencies
RUN mkdir -p /home/node/app && chown -R node:node /home/node/app
WORKDIR /home/node/app
COPY package*.json ./
USER node
COPY --chown=node:node . .
ENV NPM_CONFIG_PREFIX=/home/node/.npm-global
RUN npm install
EXPOSE 3000
CMD ["node", "app.js"]

docker-compose.yml:

version: "3.5"
services:
  app:
    container_name: app
    restart: always
    build: .
    ports:
      - "3000:3000"
    networks:
      - mongo
  mongo:
    restart: always
    container_name: mongo
    image: mongo
    expose: 
      - 27017
    volumes:
      - mongodata:/data/db
    ports:
      - '27017:27017'
    networks:
      - mongo
volumes:
  mongodata:
networks:
  mongo:
    external: true

来自app.js的代码段:

MongoClient.connect('mongodb://mongo:27017/project', {useNewUrlParser: true}, (err, client) => {
    if (err) throw err; //throws MongoNetworkError: failed to connect to server [mongo:27017] on first connect [MongoNetworkError: getaddrinfo ENOTFOUND mongo mongo:27017]
    console.log("connected");
    client.close();//at the moment this line is not being reached because of throw err;
});```

Answer 1

如果在连接到mongo数据库之前在应用程序中插入“sleep 10”是否有帮助？如果是这样，添加类似wiatforit(https://github.com/maxcnunes/waitforit)的内容可能会有所帮助。