🚀 Automate full Nginx reverse proxy + SSL setup for multiple domains/subdomains on your VPS!

setupdomain.sh

#!/bin/bash

# Exit on error
set -e

# Usage
if [ $# -lt 3 ]; then
    echo "Usage: $0 <local_port> <email> <domain1> [domain2] [domain3] ..."
    echo "Example: $0 3000 [email protected] example.com api.example.com"
    exit 1
fi

LOCAL_PORT=$1
EMAIL=$2
shift 2
DOMAINS=("$@")
PRIMARY_DOMAIN=${DOMAINS[0]}  # Used for config file naming
NGINX_CONF="/etc/nginx/sites-available/$PRIMARY_DOMAIN"

echo "🛠 Setting up domains: ${DOMAINS[*]} to forward traffic to localhost:$LOCAL_PORT with SSL..."

# Install dependencies
if ! command -v nginx &> /dev/null; then
    echo "🔹 Installing Nginx..."
    sudo apt update
    sudo apt install -y nginx
fi

if ! command -v certbot &> /dev/null; then
    echo "🔹 Installing Certbot..."
    sudo apt install -y certbot python3-certbot-nginx
fi

# Build server_name list
SERVER_NAMES=$(IFS=' '; echo "${DOMAINS[*]}")

# Create Nginx config
echo "🔹 Creating Nginx config for domains..."
sudo tee "$NGINX_CONF" > /dev/null <<EOF
server {
    listen 80;
    server_name $SERVER_NAMES;

    location / {
        proxy_pass http://127.0.0.1:$LOCAL_PORT;
        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;
    }
}
EOF

# Enable config
echo "🔹 Enabling site configuration..."
sudo ln -sf "$NGINX_CONF" /etc/nginx/sites-enabled/

# Test config and restart Nginx
echo "🔹 Testing Nginx configuration..."
sudo nginx -t

echo "🔹 Restarting Nginx..."
sudo systemctl restart nginx

# Build certbot domain args
CERTBOT_DOMAINS=()
for DOMAIN in "${DOMAINS[@]}"; do
    CERTBOT_DOMAINS+=("-d" "$DOMAIN")
done

# Request SSL cert
echo "🔹 Requesting SSL certificates for: ${DOMAINS[*]}"
sudo certbot --nginx "${CERTBOT_DOMAINS[@]}" --non-interactive --agree-tos -m "$EMAIL"

# Set up SSL renewal
echo "🔹 Enabling auto-renewal for SSL..."
sudo systemctl enable certbot.timer
sudo systemctl start certbot.timer

# Final restart
echo "🔹 Restarting Nginx..."
sudo systemctl restart nginx

echo "✅ All domains are now secured and forwarded to localhost:$LOCAL_PORT"

Automate Nginx Domain Configuration for VPS Server
Simplify reverse proxy + SSL with one script!

🚀 How to Use
1️⃣ Save the script as setupdomain.sh

nano setupdomain.sh

Paste the script, then save & exit (CTRL + X, then Y, then ENTER).

2️⃣ Make it executable

chmod +x setupdomain.sh

3️⃣ Run the script with your app port, SSL email, and domains (main + subdomains)

./setupdomain.sh 3000 [email protected] example.com api.example.com dashboard.example.com

🎯 What This Script Does
✔ Installs Nginx & Certbot (if missing)
✔ Creates and enables a reverse proxy config for one or more domains/subdomains
✔ Automatically requests and installs a free SSL certificate via Let's Encrypt
✔ Enables auto-renewal for all SSL certs
✔ Restarts Nginx to apply changes instantly

🛡️ Works with both main domains (example.com) and subdomains (api.example.com, etc.)
📦 Ideal for web apps running on a VPS behind any local port (Node.js, PHP, etc.)
💡 Minimal input, maximum automation.