---
title: "Apache HTTP Server Cheatsheet | FindUtils"
description: "Virtual hosts, modules, SSL, .htaccess, reverse proxy, and performance tuning"
url: https://findutils.com/cheatsheets/apache-server/
---

# Apache HTTP Server Cheatsheet

Virtual hosts, modules, SSL, .htaccess, reverse proxy, and performance tuning 64 commands in 9 sections, filed under [DevOps & Cloud](https://findutils.com/cheatsheets/devops/).

## Service Management

- `sudo systemctl start apache2`: Start Apache service
- `sudo systemctl stop apache2`: Stop Apache service
- `sudo systemctl restart apache2`: Restart Apache (drops connections)
- `sudo systemctl reload apache2`: Graceful reload (no downtime)
- `sudo systemctl enable apache2`: Enable Apache on boot
- `sudo systemctl status apache2`: Check Apache service status
- `apachectl configtest`: Test configuration syntax
- `apachectl -V`: Show version and build parameters
- `apachectl -t -D DUMP_MODULES`: List all loaded modules
- `apachectl -S`: Show parsed virtual host settings

## Virtual Hosts

- `<VirtualHost *:80>`: Define a virtual host on port 80
- `ServerName example.com`: Set primary domain for vhost
- `ServerAlias www.example.com`: Add alternate domain name
- `DocumentRoot /var/www/html`: Set root directory for content
- `ErrorLog ${APACHE_LOG_DIR}/error.log`: Set error log path
- `CustomLog ${APACHE_LOG_DIR}/access.log combined`: Set access log with format
- `sudo a2ensite example.conf`: Enable a virtual host config
- `sudo a2dissite example.conf`: Disable a virtual host config

## Modules

- `sudo a2enmod rewrite`: Enable mod_rewrite for URL rewriting
- `sudo a2dismod autoindex`: Disable directory listing module
- `sudo a2enmod ssl`: Enable SSL/TLS module
- `sudo a2enmod headers`: Enable HTTP headers module
- `sudo a2enmod proxy`: Enable reverse proxy module
- `sudo a2enmod proxy_http`: Enable HTTP proxy support
- `sudo a2enmod expires`: Enable cache expiry headers
- `sudo a2enmod deflate`: Enable gzip compression
- `apache2ctl -M`: List all enabled modules

## SSL / HTTPS

- `sudo a2enmod ssl`: Enable SSL module
- `SSLEngine on`: Enable SSL for a virtual host
- `SSLCertificateFile /path/cert.pem`: Set SSL certificate path
- `SSLCertificateKeyFile /path/key.pem`: Set SSL private key path
- `SSLCertificateChainFile /path/chain.pem`: Set certificate chain file
- `sudo certbot --apache -d example.com`: Install Let's Encrypt cert
- `Header always set Strict-Transport-Security "max-age=31536000"`: Enable HSTS header

## .htaccess & Rewrite Rules

- `RewriteEngine On`: Enable URL rewriting in .htaccess
- `RewriteCond %{HTTPS} off`: Condition: if not HTTPS
- `RewriteRule ^(.*)$ https://%{HTTP_HOST}/$1 [R=301,L]`: Redirect HTTP to HTTPS
- `RewriteRule ^old-page$ /new-page [R=301,L]`: Permanent redirect (301)
- `RewriteRule ^api/(.*)$ index.php?route=$1 [QSA,L]`: Route API requests to index.php
- `Options -Indexes`: Disable directory listing
- `AllowOverride All`: Allow .htaccess to override config
- `ErrorDocument 404 /404.html`: Custom 404 error page

## Reverse Proxy

- `ProxyPass / http://localhost:3000/`: Forward all requests to backend
- `ProxyPassReverse / http://localhost:3000/`: Adjust response headers for proxy
- `ProxyPreserveHost On`: Pass original Host header to backend
- `ProxyPass /ws ws://localhost:3000/ws`: Proxy WebSocket connections
- `<Proxy balancer://mycluster>`: Define a load balancer cluster
- `BalancerMember http://server1:8080`: Add backend server to balancer

## Security & Access Control

- `Require all denied`: Deny access to directory (2.4+)
- `Require ip 192.168.1.0/24`: Allow access from IP range
- `Require all granted`: Allow access to all
- `ServerTokens Prod`: Hide Apache version in headers
- `ServerSignature Off`: Remove server info from error pages
- `Header set X-Content-Type-Options "nosniff"`: Prevent MIME type sniffing
- `Header set X-Frame-Options "SAMEORIGIN"`: Prevent clickjacking

## Logging & Performance

- `LogLevel warn`: Set log verbosity (emerg to trace8)
- `tail -f /var/log/apache2/error.log`: Stream error log in real-time
- `ExpiresActive On`: Enable cache expiry headers
- `ExpiresByType image/png "access plus 1 month"`: Cache images for 1 month
- `AddOutputFilterByType DEFLATE text/html text/css`: Enable gzip for HTML/CSS
- `KeepAlive On`: Enable persistent connections
- `MaxKeepAliveRequests 100`: Max requests per connection
- `KeepAliveTimeout 5`: Timeout for keep-alive (seconds)

## Sources

- `https://httpd.apache.org/docs/2.4/`: Apache HTTP Server 2.4 manual: directive contexts, modules, TLS, and proxy configuration.

## Related

- Cheatsheet: [Docker Commands](https://findutils.com/cheatsheets/docker-commands/)
- Cheatsheet: [Kubernetes Commands](https://findutils.com/cheatsheets/kubernetes-commands/)
- Cheatsheet: [Nginx Server](https://findutils.com/cheatsheets/nginx-server/)