节点和mongo之间的docker-compose连接

Question

I read a lots of examples about connecting apps with docker, it seems really simple

Im my case I have

version: '2'

services:

  mongodb:
    image: mongo
    container_name: infra-mongodb
    restart: always
    environment:
      - MONGO_INITDB_ROOT_USERNAME=admin
      - MONGO_INITDB_ROOT_PASSWORD=admin
    ports:
      - 27017:27017
  service:
    build:
      context: .
    container_name: service
    restart: always
    ports:
      - 3012:3012
    depends_on:
      - mongodb
    links:
      - mongodb

My connection in node is

const MongoClient = require('mongodb').MongoClient;
const mongoUrl = 'mongodb://admin:admin@mongodb:27017/admin?replicaSet=rs0&slaveOk=true'
MongoClient.connect(mongoUrl, { useNewUrlParser: true }, (err, client) => {
    console.log(err)
});

I have the following error

{ MongoNetworkError: failed to connect to server [9d574801e4b4:27017] on first connect [MongoNetworkError: getaddrinfo ENOTFOUND 9d574801e4b4 9d574801e4b4:27017]
    at Pool.<anonymous> (/usr/src/app/node_modules/mongodb-core/lib/topologies/server.js:564:11)
    at emitOne (events.js:116:13)
    at Pool.emit (events.js:211:7)
    at Connection.<anonymous> (/usr/src/app/node_modules/mongodb-core/lib/connection/pool.js:317:12)
    at Object.onceWrapper (events.js:317:30)
    at emitTwo (events.js:126:13)
    at Connection.emit (events.js:214:7)
    at Socket.<anonymous> (/usr/src/app/node_modules/mongodb-core/lib/connection/connection.js:246:50)
    at Object.onceWrapper (events.js:315:30)
    at emitOne (events.js:116:13)
    at Socket.emit (events.js:211:7)
    at emitErrorNT (internal/streams/destroy.js:64:8)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickCallback (internal/process/next_tick.js:180:9)
  name: 'MongoNetworkError',
  errorLabels: [ 'TransientTransactionError' ],
  [Symbol(mongoErrorContextSymbol)]: {} }

I do not understand why the host become 9d574801e4b4

When I run ping mongodb into my container everything is fine

PING mongodb (172.21.0.3) 56(84) bytes of data.
64 bytes from infra-mongodb.app-admin_default (172.21.0.3): icmp_seq=1 ttl=64 time=0.088 ms
64 bytes from infra-mongodb.app-admin_default (172.21.0.3): icmp_seq=2 ttl=64 time=0.101 ms
64 bytes from infra-mongodb.app-admin_default (172.21.0.3): icmp_seq=3 ttl=64 time=0.102 ms
64 bytes from infra-mongodb.app-admin_default (172.21.0.3): icmp_seq=4 ttl=64 time=0.216 ms
^C
--- mongodb ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3156ms
rtt min/avg/max/mdev = 0.088/0.126/0.216/0.053 ms

Answer 1

By default mongo listens on localhost only. If it is for local development, simply bind it to all interfaces :

version: '2'

services:

  mongodb:
    image: mongo
    container_name: infra-mongodb
    restart: always
    environment:
      - MONGO_INITDB_ROOT_USERNAME=admin
      - MONGO_INITDB_ROOT_PASSWORD=admin
    ports:
      - 27017:27017
    command: --bind_ip_all

Answer 2

Just a guess here, but the depends_on field in Docker Compose only means "this container has to wait until the other one is started." The service inside doesn't necessarily have to be up and running yet. So your application may be starting too quickly. The Mongo server may not be ready to accept connections yet when your app tries to connect. Run docker-compose up , wait for it to fail to start, and then run docker-compose restart service .

If this fixes it, then you will probably want to make your application retry connecting after some sort of timeout if it fails to connect on start up.

Answer 3

Check this out:

docker-compose.yaml

version: '2' 

services:
  nodejs:
    container_name: nodejs
    image: nexus.XXXX.com:8000/${BE_BUILD}
    restart: always
    environment:
       - dbhost=mongo
    ports:
      - "8888:8888"
    links:
      - mongo
  mongo:
    container_name: mongo
    image: nexus.XXXX.com:8000/doc/docker/proj-mongodb:latest
    restart: always
    environment:
      - MONGO_INITDB_ROOT_USERNAME=admin
      - MONGO_INITDB_ROOT_PASSWORD=admin
    ports:
      - "27017:27017"

And I am successfully able to connect by below URL:

const mongoUrl = mongodb://admin:admin@mongo:27017/admin?authSource=admin

---

Check below things that can solve the issue:

• Set dbHost name from NodeJS configuration.
• Link mongo container from NodeJS configuration.
• Use container name to connect.
• Check if authSource require to the URL.

Answer 4

Just find the issue I do not really understand how does it works ...

version: '2'

services:

  mongodb:
    image: mongo
    container_name: infra-mongodb
    restart: always
    environment:
      - MONGO_INITDB_ROOT_USERNAME=admin
      - MONGO_INITDB_ROOT_PASSWORD=admin
    ports:
      - 27017:27017
    networks:
      service-network:
        aliases:
            - localhost
  service:
    build:
      context: .
    container_name: service
    restart: always
    ports:
      - 3012:3012
    depends_on:
      - mongodb
    links:
      - mongodb

networks:
  app-admin-network:
    driver: bridge

Answer 5

Can't see the docker-compose up log but. had similar problem today. Solved with a small script I have made. wait-for-mongo In your dockerfile add this:

RUN npm install -g wait-for-mongodb-slim

## Launch the wait tool and then your application
CMD wait-for-mongo --uri $MONGO_URI --t 2.5 && npm start

where --t is the sceonds until it checks again.

and on your compose add the uri as an environment variable:

environment:
   MONGO_URI: mongodb://usr:pw@containername:27017/dbname