MongooseServerSelectionError ECONNREFUSED with a docker-compose using mongo container-CodePudding

I'm trying to dockerize my MERN stack application in Docker and I'm able to get all the services to run in containers on a docker network using docker-compose with a .yml file but for some reason, my app is not able to connect to the mongo service. I was able to get the app to work on my localhost but in Docker, it is not working.

Mongo connection with mongoose on backend:

const mongoURI = `mongodb://${MONGOUN}:${MONGOPW}@mongodb:27018/names`;

mongoose.connect(mongoURI, { useUnifiedTopology: true, useNewUrlParser: true })
  .then(() => {
    console.log('mongo connection established');
  })
  .catch((error) => {
    console.log(`mongo connect error on ${mongoURI}`);
    console.log(error);
  });

const db = mongoose.connection;

db
  .then(() => {
    console.log(`connected to mongoose`);
  })
  .catch((err) => {
    console.log(`error connecting to mongoose`);
    console.log(err);
  });

docker-compose .yml file:

version: '3.1'
services:
  app:
    restart: always
    build: .
    ports:
      - 3000:3000
    links:
      - mongodb
  mongodb:
    image: mongo
    ports:
      - 27018:27018
    expose:
      - "27018"
    environment:
      MONGO_INITDB_ROOT_USERNAME: admin
      MONGO_INITDB_ROOT_PASSWORD: password
      MONGO_INITDB_DATABASE: names
  mongo-express:
    image: mongo-express
    ports:
      - 8080:8081
    depends_on:
      - mongodb
    environment:
      ME_CONFIG_MONGODB_ADMINUSERNAME: admin
      ME_CONFIG_MONGODB_ADMINPASSWORD: password
      ME_CONFIG_MONGODB_SERVER: mongodb
    restart: unless-stopped

Dockerfile:

FROM node:14-alpine

RUN mkdir -p /home/app

COPY . /home/app

WORKDIR "/home/app"

EXPOSE 3000

CMD ["npm", "start"]

Error message in Docker terminal:

app_1      | connected to mongoose
app_1      | mongo connect error on mongodb://admin:password@mongodb:27018/names
app_1      | MongooseServerSelectionError: connect ECONNREFUSED 192.168.48.2:27018
app_1      |     at NativeConnection.Connection.openUri (/home/app/node_modules/mongoose/lib/connection.js:846:32)
app_1      |     at /home/app/node_modules/mongoose/lib/index.js:351:10
app_1      |     at /home/app/node_modules/mongoose/lib/helpers/promiseOrCallback.js:32:5
app_1      |     at new Promise (<anonymous>)
app_1      |     at promiseOrCallback (/home/app/node_modules/mongoose/lib/helpers/promiseOrCallback.js:31:10)
app_1      |     at Mongoose._promiseOrCallback (/home/app/node_modules/mongoose/lib/index.js:1149:10)
app_1      |     at Mongoose.connect (/home/app/node_modules/mongoose/lib/index.js:350:20)
app_1      |     at Object.<anonymous> (/home/app/server/db/index.js:7:10)
app_1      |     at Module._compile (internal/modules/cjs/loader.js:1085:14)
app_1      |     at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)
app_1      |     at Module.load (internal/modules/cjs/loader.js:950:32)
app_1      |     at Function.Module._load (internal/modules/cjs/loader.js:790:12)
app_1      |     at Module.require (internal/modules/cjs/loader.js:974:19)
app_1      |     at require (internal/modules/cjs/helpers.js:93:18)
app_1      |     at Object.<anonymous> (/home/app/server/index.js:3:12)
app_1      |     at Module._compile (internal/modules/cjs/loader.js:1085:14) {
app_1      |   reason: TopologyDescription {
app_1      |     type: 'Single',
app_1      |     setName: null,
app_1      |     maxSetVersion: null,
app_1      |     maxElectionId: null,
app_1      |     servers: Map(1) { 'mongodb:27018' => [ServerDescription] },
app_1      |     stale: false,
app_1      |     compatible: true,
app_1      |     compatibilityError: null,
app_1      |     logicalSessionTimeoutMinutes: null,
app_1      |     heartbeatFrequencyMS: 10000,
app_1      |     localThresholdMS: 15,
app_1      |     commonWireVersion: null
app_1      |   }
app_1      | }

I'm just getting started with learning Docker so I've mainly been looking online at tutorials and other examples. I have hit a roadblock here though.

Here is the repo: https://github.com/nickhanrahan/shareport

Can anyone point me in the right direction here? Any help would be appreciated.

CodePudding user response：

mongodb uses port 27017 not 27018

version: '3.1'
services:
  app:
    restart: always
    build: .
    ports:
      - 3000:3000
    links:
      - mongodb
  mongodb:
    image: mongo
    ports:
      - 27017:27017
    expose:
      - "27017"
    environment:
      MONGO_INITDB_ROOT_USERNAME: admin
      MONGO_INITDB_ROOT_PASSWORD: password
      MONGO_INITDB_DATABASE: names
  mongo-express:
    image: mongo-express
    ports:
      - 8080:8081
    depends_on:
      - mongodb
    environment:
      ME_CONFIG_MONGODB_ADMINUSERNAME: admin
      ME_CONFIG_MONGODB_ADMINPASSWORD: password
      ME_CONFIG_MONGODB_SERVER: mongodb
      ME_CONFIG_MONGODB_PORT: 27017
    restart: unless-stopped

don't forget changes in server/db/index.js

const mongoURI = mongodb://${MONGOUN}:${MONGOPW}@mongodb:27017..