Node.js Framework Selection

When choosing a Node.js framework, consider:

• Koa2 - Minimalist framework with middleware support
• Express - Most popular with extensive middleware ecosystem
• Egg.js - Enterprise framework built on Koa
• NestJS - TypeScript framework with Angular-like architecture

// Koa2 basic server example
const Koa = require('koa');
const app = new Koa();

app.use(async ctx => {
  ctx.body = 'Hello World';
});

app.listen(3000);

Database Technologies

Relational Database (MySQL)

Using Sequelize ORM:

const { Sequelize } = require('sequelize');
const sequelize = new Sequelize('database', 'user', 'password', {
  host: 'localhost',
  dialect: 'mysql'
});

Document Data base (MongoDB)

Using Mongoose ODM:

const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/test', {useNewUrlParser: true});

const Schema = mongoose.Schema;
const blogSchema = new Schema({
  title: String,
  content: String
});

In-Memory Database (Redis)

const redis = require('redis');
const client = redis.createClient();

client.set('key', 'value', redis.print);
client.get('key', (err, reply) => {
  console.log(reply);
});

Authentication Strtaegies

JWT Implementation

const jwt = require('jsonwebtoken');
const token = jwt.sign({ userId: 123 }, 'secret', { expiresIn: '1h' });

// Verify middleware
const verifyToken = (req, res, next) => {
  const token = req.headers['authorization'];
  if (!token) return res.status(403).send('Token required');
  
  jwt.verify(token, 'secret', (err, decoded) => {
    if (err) return res.status(500).send('Invalid token');
    req.userId = decoded.userId;
    next();
  });
};

Testing Strategeis

Unit Testing with Jest

// math.js
function sum(a, b) {
  return a + b;
}
module.exports = sum;

// math.test.js
const sum = require('./math');
test('adds 1 + 2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3);
});

API Testing with Supertest

const request = require('supertest');
const app = require('../app');

describe('GET /users', () => {
  it('responds with json', async () => {
    const response = await request(app)
      .get('/users')
      .expect('Content-Type', /json/)
      .expect(200);
  });
});

Deployment Configuration

PM2 Process Manager

module.exports = {
  apps: [{
    name: 'api-server',
    script: './server.js',
    instances: 'max',
    exec_mode: 'cluster',
    env: {
      NODE_ENV: 'production'
    }
  }]
};

Nginx Reverse Proxy

server {
  listen 80;
  server_name api.example.com;

  location / {
    proxy_pass http://localhost:3000;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
  }
}

CI/CD with GitHub Actions

name: Node.js CI

on: [push]

jobs:
  build:
    runs-on: ubuntu-latest
    
    steps:
    - uses: actions/checkout@v2
    - name: Use Node.js
      uses: actions/setup-node@v1
      with:
        node-version: '14.x'
    - run: npm install
    - run: npm test

Docker Configuration

# Dockerfile
FROM node:14-alpine
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 3000
CMD ["node", "server.js"]

Docker Compose

version: '3'
services:
  web:
    build: .
    ports:
      - "3000:3000"
  redis:
    image: "redis:alpine"