Web Server Configuration Skill

This skill provides comprehensive configuration guides, best practices, and templates for web servers including Nginx, Apache, Traefik, and Caddy.

When to Use This Skill

Use this skill when:

• Installing and configuring web servers
• Setting up SSL/TLS certificates
• Configuring reverse proxy
• Implementing load balancing
• Optimizing performance
• Adding security headers
• Setting up virtual hosts
• Configuring caching

Web Server Selection Guide

┌─────────────────────────────────────────────────────────────┐
│ Choose Web Server Based On:                                 │
├─────────────────────────────────────────────────────────────┤
│                                                             │
│ Nginx:                                                      │
│   ✓ High performance & scalability                          │
│   ✓ Reverse proxy & load balancing                          │
│   ✓ Static file serving                                     │
│   ✓ Low memory footprint                                    │
│                                                             │
│ Apache:                                                     │
│   ✓ .htaccess support                                       │
│   ✓ Module ecosystem                                        │
│   ✓ Legacy application support                              │
│   ✓ Dynamic content                                         │
│                                                             │
│ Traefik:                                                    │
│   ✓ Kubernetes ingress                                      │
│   ✓ Docker integration                                      │
│   ✓ Automatic SSL (Let's Encrypt)                           │
│   ✓ Dynamic configuration                                   │
│                                                             │
│ Caddy:                                                      │
│   ✓ Automatic HTTPS                                         │
│   ✓ Simple configuration                                    │
│   ✓ HTTP/2 push                                             │
│   ✓ Modern defaults                                         │
│                                                             │
└─────────────────────────────────────────────────────────────┘

Quick Start Configurations

Nginx Production Setup

# Complete production-ready Nginx configuration
# See resources/nginx-configs.md for full implementation

server {
    listen 443 ssl http2;
    server_name example.com;
    
    # SSL Configuration
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;
    
    # Security Headers
    add_header Strict-Transport-Security "max-age=63072000" always;
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    
    # Reverse Proxy
    location / {
        proxy_pass http://localhost:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

Apache Production Setup

# Complete production-ready Apache configuration
# See resources/apache-configs.md for full implementation

<VirtualHost *:443>
    ServerName example.com
    DocumentRoot /var/www/html
    
    SSLEngine on
    SSLCertificateFile /etc/letsencrypt/live/example.com/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/example.com/privkey.pem
    
    # Security Headers
    Header always set Strict-Transport-Security "max-age=63072000"
    Header always set X-Frame-Options "SAMEORIGIN"
    Header always set X-Content-Type-Options "nosniff"
    
    # Reverse Proxy
    ProxyPass / http://localhost:8080/
    ProxyPassReverse / http://localhost:8080/
</VirtualHost>

Traefik Docker Setup

# docker-compose.yml
version: '3.8'

services:
  traefik:
    image: traefik:v2.10
    command:
      - "--providers.docker=true"
      - "--entrypoints.web.address=:80"
      - "--entrypoints.websecure.address=:443"
      - "--certificatesresolvers.letsencrypt.acme.tlschallenge=true"
      - "--certificatesresolvers.letsencrypt.acme.email=admin@example.com"
      - "--certificatesresolvers.letsencrypt.acme.storage=/letsencrypt/acme.json"
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
      - ./letsencrypt:/letsencrypt

  webapp:
    image: myapp:latest
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.webapp.rule=Host(`example.com`)"
      - "traefik.http.routers.webapp.tls=true"
      - "traefik.http.routers.webapp.tls.certresolver=letsencrypt"

Caddy Simple Setup

# Caddyfile
example.com {
    reverse_proxy localhost:8080
    
    # Security headers
    header {
        Strict-Transport-Security "max-age=63072000; includeSubDomains; preload"
        X-Frame-Options "SAMEORIGIN"
        X-Content-Type-Options "nosniff"
    }
    
    # Compression
    encode zstd gzip
    
    # Logging
    log {
        output file /var/log/caddy/access.log
        format json
    }
}

SSL/TLS Configuration

Let's Encrypt Setup

#!/bin/bash
# Automated SSL with Certbot

DOMAIN=$1
EMAIL=$2

# Install Certbot
apt-get install -y certbot python3-certbot-nginx

# Obtain certificate
certbot certonly --nginx \
    --agree-tos \
    --redirect \
    --hsts \
    --staple-ocsp \
    --email $EMAIL \
    -d $DOMAIN \
    -d www.$DOMAIN

# Auto-renewal
echo "0 3 * * * certbot renew --quiet --deploy-hook 'systemctl reload nginx'" | crontab -

Security Headers

Essential Headers

# Security Headers (all web servers)
Strict-Transport-Security: max-age=63072000; includeSubDomains; preload
X-Frame-Options: DENY
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Referrer-Policy: strict-origin-when-cross-origin
Content-Security-Policy: default-src 'self'
Permissions-Policy: geolocation=(), microphone=(), camera=()
Cache-Control: no-store, no-cache, must-revalidate

Performance Optimization

Compression

# Nginx Gzip
gzip on;
gzip_vary on;
gzip_comp_level 6;
gzip_types text/plain text/css application/json application/javascript;

# Nginx Brotli (better)
brotli on;
brotli_comp_level 6;
brotli_types text/plain text/css application/json application/javascript;

Caching

# Static files
location /static/ {
    expires 30d;
    add_header Cache-Control "public, immutable";
}

# API responses
location /api/ {
    add_header Cache-Control "no-store, no-cache, must-revalidate";
}

Load Balancing

Nginx Load Balancer

upstream backend {
    least_conn;
    server 10.0.1.10:8080;
    server 10.0.1.11:8080;
    server 10.0.1.12:8080 backup;
    
    keepalive 32;
}

server {
    location / {
        proxy_pass http://backend;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
    }
}

Implementation Resources

Refer to the following resources in this skill for detailed implementations:

• resources/nginx-configs.md: Complete Nginx configurations for various use cases
• resources/apache-configs.md: Complete Apache configurations and virtual hosts
• resources/ssl-setup.md: SSL/TLS certificate setup and configuration
• resources/performance-tuning.md: Performance optimization techniques

Anti-Patterns

Avoid these web server mistakes:

❌ Default configurations in production ❌ Missing security headers ❌ No SSL/TLS ❌ Server version exposure ❌ Missing rate limiting ❌ No compression ❌ Improper caching ❌ No access logs ❌ Running as root ❌ No health checks

Monitoring

Essential Metrics

# Monitor these metrics:
- Response time (p95, p99)
- Requests per second
- Error rate (4xx, 5xx)
- Active connections
- SSL certificate expiry
- Upstream health
- Cache hit rate
- Bandwidth usage

Troubleshooting

Common Issues

502 Bad Gateway:

• Check upstream service status
• Verify network connectivity
• Check firewall rules

504 Gateway Timeout:

• Increase proxy timeouts
• Check upstream performance
• Monitor resource usage

SSL Errors:

• Verify certificate paths
• Check certificate expiry
• Verify domain configuration