STEP1, Create a Express.js App

terminal


    // create directory and initialize app
        mkdir express-mongo
        cd express-mongo    
        npm init -y
    
    // create file necessary
        touch server.js
        touch Dockerfile
        touch .dockerignore

    // install modules
        npm install express mongodb

server.js

    const express = require("express");
    const app = express();
    const PORT = 3000;
    const { MongoClient } = require("mongodb");
    
    app.use(express.urlencoded({ extended: true }));
    app.use(express.json());
    
    const uri = "mongodb://root:password@mongodb:27017";
    const client = new MongoClient(uri);
    
    const options = {
      useNewUrlParser: true,
      useUnifiedTopology: true,
    };
    
    app.get("/", async (req, res) => {
      try {
        await client.connect();
        const db = client.db("user-account");
        const collection = db.collection("users");
        const result = await collection.findOne({ userid: 1 }, options);
    
        res.json(result);
      } catch (error) {
        console.log(error);
      } finally {
        await client.close();
      }
    });
   
    app.listen(PORT, () => {
      console.log(`Server is running on port ${PORT}`);
    });

Dockerfile


    FROM node:alpine3.18
    
    WORKDIR /usr/src/app
    
    COPY . /usr/src/app/
    
    RUN npm install
    
    EXPOSE 3000
    
    CMD [ "node", "server.js" ]

.dockerignore

    node_modules

STEP2, Create a docker-compose.yml

docker-compose.yml


    version: "3.9"
    
    services:
      node:
        build: .
        container_name: express_app
        ports:
          - 3000:3000
        restart: always
        volumes:
          - ./:/usr/src/app
        networks:
          - mongo-network
        depends_on:
          - mongodb
    
      mongodb:
        image: mongo
        container_name: mongo_db
        restart: always
        ports:
          - 27017:27017
        environment:
          MONGO_INITDB_ROOT_USERNAME: root
          MONGO_INITDB_ROOT_PASSWORD: password
        volumes:
          - mongo_db:/data/db
          - config_db:/data/configdb
        networks:
          - mongo-network
    
      mongo-express:
        image: mongo-express
        container_name: mongo_express
        restart: always
        ports:
          - 8081:8081
        environment:
          ME_CONFIG_OPTIONS_EDITORTHEME: ambiance
          ME_CONFIG_MONGODB_ADMINUSERNAME: root
          ME_CONFIG_MONGODB_ADMINPASSWORD: password
          ME_CONFIG_MONGODB_SERVER: mongodb
        networks:
          - mongo-network
        depends_on:
          - mongodb
    
    networks:
      mongo-network:
    
    volumes:
      mongo_db:
      config_db:

STEP3, docker compose up -d

terminal

    docker compose up -d

all container is running successfully

STEP4, insert data to mongoDB

open http://localhost:8081

create database "user-account"

create collection "users"

STEP5, Access to http://localhost:3000

you can see the data from mongodb successfully!!

STEP6, Down docker compose

terminal

    
    docker compose down