Using Docker Compose 3.8 with Node.js and MongoDB

This article shows you how to use Docker Compose with Node.js and MongoDB in the simplest way.

Note: I’ll use version 3.8 of Compose file format but any 3.x version is totally fine.

The Code

The project structure:

├── docker-compose.yml
└── node-web
    ├── Dockerfile
    ├── index.js
    ├── node_modules
    └── package.json

The docker-compose.yml file:

version: '3.8'
services: 
  database:
    image: mongo
    restart: always 
    environment: 
      - MONGO_INITDB_ROOT_USERNAME=my-username
      - MONGO_INITDB_ROOT_PASSWORD=my-root-password
    volumes: 
      - my_data:/data/db 
  node-web:
    build: 
      context: ./node-web
      dockerfile: Dockerfile
    depends_on: 
      - database
    volumes: 
      - /app/node_modules
      - ./node-web:/app 
    ports: 
      - "5000:5000"
  
volumes: 
  my_data: 

The Dockerfile in the node-web folder:

FROM node:alpine
WORKDIR "/app"
COPY ./package.json ./
RUN npm install
COPY . .
CMD ["npm", "run", "dev"]

The package.json file:

{
  "name": "my-node-app",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "dev": "nodemon index.js"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.18.1",
    "mongodb": "^4.9.1"
  },
  "devDependencies": {
    "nodemon": "^2.0.19"
  }
}

The index.js file:

const express = require('express');
const MongoClient = require('mongodb').MongoClient;

const app = express();

// The default url used to connect to MongoDB is mongodb://[service-name-decribed-in-the-compose-file]:/27017
// In this case, the service name is "database"
const url = 'mongodb://database:27017';

// Connect to MongoDB
MongoClient.connect(url, (err, client) => {
  if(err){
    throw new Error('Could not connect to the database');
  }

  console.log('Successfully connected to the database');

  // Interact with Mongodb 
  // Insert, update .... 
  // See the docs at: 
  // https://www.npmjs.com/package/mongodb
  // or:
  // https://github.com/mongodb/node-mongodb-native
})

// Some other code 
app.get('/', (req, res) => {
  res.send('Hi!');
});

app.listen(5000, () => { 
  console.log('Express is listening on port 5000!')
})

Here is the structure of the default URL for connecting to MongoDB:

mongodb://[service-name]:/27017

Run

docker-compose up --build

Wait a minute or two and you will see something like this in the terminal (versions of packages might be different, don’t worry about this):

node-web_1  | Express is listening on port 5000!
database_1  | {"t":{"$date":"2020-10-03T16:43:59.607+00:00"},"s":"I",  "c":"NETWORK",  "id":22943,   "ctx":"listener","msg":"Connection accepted","attr":{"remote":"172.28.0.3:33296","connectionId":1,"connectionCount":1}}
database_1  | {"t":{"$date":"2020-10-03T16:43:59.610+00:00"},"s":"I",  "c":"NETWORK",  "id":51800,   "ctx":"conn1","msg":"client metadata","attr":{"remote":"172.28.0.3:33296","client":"conn1","doc":{"driver":{"name":"nodejs","version":"3.6.2"},"os":{"type":"Linux","name":"linux","architecture":"x64","version":"4.19.76-linuxkit"},"platform":"'Node.js v14.12.0, LE (legacy)"}}}
node-web_1  | Successfully connected to the database

Note:

• You should only use Nodemon in the development environment.
• You may see some warnings when running docker-compose up for the first time but there is no need to worry about them.

Further reading:

• Using Docker Compose to speed up WordPress development
• How to Install Docker Compose on Ubuntu
• Deleting unnecessary Images and Containers in Docker
• Start, Pause, Restart, Stop, and Delete a Docker Container
• Docker: How to Name or Rename a Container

You can also check out our Docker topic page for the latest tutorials, examples, tips, and tricks.