nginx-caddy

name: nginx-caddy description: "Configure Nginx or Caddy as a reverse proxy with SSL/TLS. Use when setting up reverse proxies, Let's Encrypt certificates, routing domains to backend services, load balancing, or serving static files." category: system maturity: stable tags: [reverse-proxy, ssl, certbot, load-balancing, caddyfile]

Nginx & Caddy Skill

Configure Nginx or Caddy as reverse proxy with SSL.

Use When

• Setting up reverse proxies for web services
• Configuring SSL/TLS certificates (Let's Encrypt)
• Routing domains to backend services
• Load balancing or serving static files

Nginx Quick Reference

Common Commands

# Test config syntax
sudo nginx -t

# Reload (graceful)
sudo systemctl reload nginx

# View error log
sudo tail -f /var/log/nginx/error.log

# View access log
sudo tail -f /var/log/nginx/access.log

Reverse Proxy (with SSL via Certbot)

server {
    listen 80;
    server_name example.com;
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl http2;
    server_name example.com;

    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;

    location / {
        proxy_pass http://127.0.0.1:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

WebSocket Proxy

location /ws {
    proxy_pass http://127.0.0.1:8080;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_set_header Host $host;
}

Static Files

server {
    listen 80;
    server_name static.example.com;
    root /var/www/static;
    index index.html;

    location / {
        try_files $uri $uri/ =404;
    }

    # Cache static assets
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff2)$ {
        expires 30d;
        add_header Cache-Control "public, immutable";
    }
}

SSL with Certbot

# Install
sudo apt install certbot python3-certbot-nginx

# Get cert + auto-configure nginx
sudo certbot --nginx -d example.com -d www.example.com

# Renew all certs
sudo certbot renew --dry-run

# Auto-renewal is installed via systemd timer
systemctl list-timers | grep certbot

Caddy Quick Reference

Caddy auto-provisions SSL certificates. Much simpler config.

Caddyfile — Reverse Proxy

example.com {
    reverse_proxy localhost:8080
}

That's it. SSL is automatic.

Caddyfile — Multiple Sites

example.com {
    reverse_proxy localhost:8080
}

api.example.com {
    reverse_proxy localhost:3000
}

static.example.com {
    root * /var/www/static
    file_server
}

Caddyfile — With Options

example.com {
    reverse_proxy localhost:8080 {
        header_up Host {host}
        header_up X-Real-IP {remote}
        health_uri /health
        health_interval 30s
    }

    log {
        output file /var/log/caddy/access.log
    }

    encode gzip
}

Caddy Commands

# Validate config
caddy validate --config /etc/caddy/Caddyfile

# Reload
sudo systemctl reload caddy

# Format Caddyfile
caddy fmt --overwrite /etc/caddy/Caddyfile

# Run in foreground (dev)
caddy run --config Caddyfile

Caddy — Load Balancing

example.com {
    reverse_proxy localhost:8081 localhost:8082 localhost:8083 {
        lb_policy round_robin
        health_uri /health
    }
}

Helper Scripts

Generate Nginx site config

bash scripts/nginx-gen.sh <domain> <backend-port> [--ssl] [--websocket]

Generate Caddy config

bash scripts/caddy-gen.sh <domain> <backend-port> [--static <path>]

Check SSL certificate

bash scripts/ssl-check.sh <domain>

Installation

# Nginx
sudo apt install nginx

# Caddy
sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list
sudo apt update && sudo apt install caddy

# Certbot (for Nginx SSL)
sudo apt install certbot python3-certbot-nginx

Nginx vs Caddy Decision