Building API Microservices into Docker containers each one with MongoDB and MySQL and API Gateway Pattern in Node.js

Hi, Devs!

Let's learn how to build API Microservices dockerized, each one with a specific database (MongoDB and MySQL) and make this available structuring an API Gateway pattern?

The complete project is here: https://github.com/luizcalaca/microservices-nodejs-docker-gateway-api Do not forget to give it a star ⭐️ and play around with the code.

---

What is Microservices and API Gateway pattern?

• Microservice Architecture is an architectural way to build software that organize an application as a collection of small autonomous services thinking in a business domain.

• API Gateway is a way to centralize all routes that will be accessible through an endpoint. Why to use? Because we could have a lot of microservices in many containers with many routes, so would be a way to organize this amount.

---

Let's go on and look at image from Azure, here we are going to build de Microservices and the API Gateway with its endpoint to the client.

We can create threes folders each one with its index.js and Node.js:

mkdir orders && cd orders && npm init -y && touch index.js
mkdir products && cd orders && npm init -y && touch index.js
mkdir api-gateway && cd gateway && npm init -y && touch index.js


index.js orders:

const app = require('express')();

app.get('/orders', (req, res) => res.send('Hello Orders, API!'));

app.listen(3000, () => console.log(`Products API listening on port 3000!`));

index.js products:

const app = require('express')();

app.get('/products', (req, res) => res.send('Hello Products, API with MySQL!'));

app.listen(3000, () => console.log(`Products API listening on port 3000!`));

index.js api-gateway:

const express = require('express');
const { createProxyMiddleware } = require('http-proxy-middleware');

const app = express();
const port = 3007;

const {
  ORDERS_API_URL,
  PRODUCTS_API_URL,
} = require('./URLs');

const optionsProducts = {
  target: PRODUCTS_API_URL,
  changeOrigin: true, 
  logger: console,
};

const optionsOrders = {
  target: ORDERS_API_URL,
  changeOrigin: true, 
  logger: console,
};

const productsProxy = createProxyMiddleware(optionsProducts);
const ordersProxy = createProxyMiddleware(optionsOrders);

app.get('/', (req, res) => res.send('Hello Gateway API'));
app.get('/orders', ordersProxy);
app.get('/products', productsProxy);

app.listen(port, () => console.log(`Example app listening on port ${port}!`));

URLs.js in the same index.js file hierarchy on api-gateway:

module.exports = {
    ORDERS_API_URL: 'http://localhost:3005',
    PRODUCTS_API_URL: 'http://localhost:3006',
  };

Add the npm start script in all package.json:

 "scripts": {
    "start": "node index.js"
  }

After let's install express and express-http-proxy:


cd orders && npm i express
cd orders && npm i express
cd api-gateway && npm i express express-http-proxy


Let's create the Dockerfile and docker-compose.yaml, first the orders with MongoDB image:

FROM node:alpine
WORKDIR /usr/app
COPY package*.json ./
RUN npm install 
COPY . . 
EXPOSE 3000
CMD npm start

version: "3"

services:
  app:
    build: .
    command: npm start
    ports:
      - "3005:3000"
    volumes:
      - .:/usr/app
    depends_on:
      - "mongo"
    networks:
      - backend

  mongo:
    container_name: "mongo-node"
    platform: linux/amd64
    image: mongo:4.4.14
    ports:
      - "8081:8081"
    environment:
      ME_CONFIG_MONGODB_ADMINUSERNAME: root
      ME_CONFIG_MONGODB_ADMINPASSWORD: root
    networks:
      - backend

networks:
  backend:
    driver: bridge

Second, the products with MySQL database image:

FROM node:alpine
WORKDIR /usr/app
COPY package*.json ./
RUN npm install 
COPY . . 
EXPOSE 3000
CMD npm start

version: "3"

services:
  app:
    build: .
    command: npm start
    ports:
      - "3006:3000"
    volumes:
      - .:/usr/app
    depends_on:
      - "mysql"
    networks:
      - backend

  mysql:
    container_name: "data-node"
    platform: linux/amd64
    image: mysql:5.7.31
    command: --default-authentication-plugin=mysql_native_password --sql_mode=NO_ENGINE_SUBSTITUTION,NO_AUTO_CREATE_USER --explicit_defaults_for_timestamp
    restart: always
    ports:
      - "3310:3306"
    environment:
      - MYSQL_ROOT_PASSWORD=root
      - TZ=America/Sao_Paulo
    networks:
      - backend

networks:
  backend:
    driver: bridge

How to run?

• products microservice with MySQL
  cd /products
docker-compose up

• orders microservice with MongoDB
  cd /orders
docker-compose up

• API Gateway Pattern Architecture
  cd /api-gateway
npm start

• Using API Gateway on browser
  http://localhost:3007/orders
http://localhost:3007/products

The complete project is here: https://github.com/luizcalaca/microservices-nodejs-docker-gateway-api Do not forget to give it a star ⭐️ and play around with the code.

"That's all folks!"

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Comments

[swetank soni]

can you also make a blog on how to deploy them over kubernetes ? I am ready to contribute. can create deployments but not sure about the whole architecture (majorly service mesh).