Deploying Multiple Node.js APIs on Single Linux Server with HTTPS

This guide will walk you through the process of deploying multiple Node.js APIs on a single Linux server and securing them with HTTPS using Nginx as a reverse proxy.

Prerequisites

• A Linux server (Ubuntu/Debian)
• Root access to the server
• Domain name pointed to your server
• Basic command line knowledge
• Node.js applications ready for deployment

Step 1: Initial Server Access and Setup

First, connect to your server and update the package list:

# Connect to your server
ssh root@your_droplet_ip

# Update package list
sudo apt update

# Install Git
sudo apt install git -y

Step 2: Installing Node.js using NVM

Install Node Version Manager (NVM) and Node.js:

# Install NVM
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.5/install.sh | bash

# Load NVM
source ~/.bashrc

# Install LTS version of Node.js
nvm install --lts

Step 3: Setting Up Project Directory

Create and navigate to the project directory:

# Create directory structure
mkdir -p /var/www && cd /var/www

# Clone your repository
git clone https://github.com/your-username/your-repo.git

# Navigate to project directory
cd your-repo

# Install project dependencies
npm install

Step 4: Environment Configuration

Create and configure environment variables:

# Create .env file
nano .env

# Add environment variables
PORT=3001
DATABASE_URL=your-database-url

Step 5: Setting Up Process Manager (PM2)

Install and configure PM2 for managing Node.js applications:

# Install PM2 globally
npm install pm2 -g

# Start first API
pm2 start index.js --name api1

# Save PM2 configuration
pm2 save

# Configure PM2 to start on system boot
pm2 startup

Step 6: Installing and Configuring Nginx

Install and configure Nginx as a reverse proxy:

# Install Nginx
sudo apt install nginx -y

# Edit Nginx configuration
sudo nano /etc/nginx/sites-available/default

Add the following configuration:

# HTTPS server block for securing API communication
server {
    listen 80; 
    server_name your-domain.com;

    # API 1 routing
    location /api1 {
        proxy_pass http://localhost:3001;   # Route to API 1 running on port 3001
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }

    # API 2 routing
    location /api2 {
        proxy_pass http://localhost:3002;   # Route to API 2 running on port 3002
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
        rewrite ^/api2(/.*)$ $1 break; # Strips the /api2 prefix before forwarding
    }
}

Test and reload Nginx configuration:

# Test Nginx configuration
sudo nginx -t

# Reload Nginx
sudo systemctl reload nginx

Step 7: Setting Up SSL/HTTPS

Install Certbot and obtain SSL certificates:

# Install Certbot and its Nginx plugin
sudo apt install certbot python3-certbot-nginx -y

# Obtain and install SSL certificate
sudo certbot --nginx -d your-domain.com

Key Features of This Setup

1. Multiple API Support

   • Different endpoints for each API (/api1, /api2)
   • Independent port numbers for each service
   • Clean URL routing

2. Security Features

   • HTTPS encryption
   • Automatic SSL certificate renewal
   • Proxy headers for security

3. Maintenance Benefits

   • Easy to add more APIs
   • Independent scaling
   • Simplified SSL management

Best Practices

1. API Management

   • Use meaningful names for PM2 processes
   • Keep track of port numbers
   • Document API endpoints

2. Security

   • Regularly update SSL certificates
   • Monitor access logs
   • Implement rate limiting

3. Monitoring

   • Use PM2 monitoring
   • Check Nginx access logs
   • Monitor SSL certificate expiry

Troubleshooting

1. Common Issues

   • Port conflicts
   • SSL certificate renewal failures
   • Nginx configuration errors

2. Debug Commands

# Check Nginx errors
sudo nginx -t
sudo tail -f /var/log/nginx/error.log

# Check PM2 logs
pm2 logs
pm2 status

# Check SSL certificate
sudo certbot certificates

Conclusion

This setup provides a robust and secure way to host multiple Node.js APIs on a single server. Remember to:

• Regularly update your SSL certificates
• Monitor your applications
• Keep your system updated
• Backup your configurations

For more advanced configurations or specific use cases, refer to the official documentation of Nginx, PM2, and Certbot.