Comprehensive Guide to Installing and Using the Caddy Web Server

Caddy is a popular, Go‑based web server with over 38K stars on GitHub, offering simple configuration via Caddyfile, dynamic Admin API, automatic HTTPS, and high scalability.

Caddy Introduction

Caddy supports static file serving and reverse proxy, and its key features include a concise Caddyfile, Admin API for live config changes, built‑in HTTPS, ability to handle thousands of sites, no extra dependencies, and memory‑safe Go implementation.

Installation

On CentOS 8, install Caddy using DNF:

dnf install 'dnf-command(copr)'
 dnf copr enable @caddy/caddy
 dnf install caddy

Check the service status with systemctl status caddy . Caddy registers as a system service but is not started automatically.

Basic Usage

Run Caddy on port 2015 to return Hello, world! :

caddy run

Use caddy start to run it in the background. Caddy can convert a Caddyfile to JSON with caddy adapter and reload the configuration with caddy reload .

Caddyfile Basic Syntax

The Caddyfile uses directives such as file_server , reverse_proxy , encode , redir , and route . A sample Caddyfile:

:2015
 respond "Hello, world!"

Reverse Proxy

Static proxy example mapping docs.macrozheng.com and mall.macrozheng.com to local directories, and dynamic proxy forwarding api.macrozheng.com to an upstream API service.

http://api.macrozheng.com {
    reverse_proxy http://admin-api.macrozheng.com
}

Gzip Compression

Enable gzip with the encode directive to reduce a 1.7 MB JavaScript file to 544 KB, improving load speed.

http://mall.macrozheng.com {
    root * /mydata/caddy/html/mall
    encode { gzip }
    file_server browse
}

Address Rewrite

Redirect old domains to new ones using redir :

http://docs.macrozheng.com {
    redir http://www.macrozheng.com
}

Directory‑Based Routing

Serve multiple front‑end projects under one domain with route and uri strip_prefix :

http://www.macrozheng.com {
    route /admin/* {
        uri strip_prefix /admin
        file_server { root /mydata/caddy/html/admin }
    }
    route /app/* {
        uri strip_prefix /app
        file_server { root /mydata/caddy/html/app }
    }
    file_server * { root /mydata/caddy/html/www }
}

HTTPS

Caddy automatically obtains TLS certificates; simply configure the domain in DNS and add a basic site block:

docs.macrozheng.com {
    root * /mydata/caddy/html/docs
    file_server browse
}

Start the server with caddy run .

Docker Support

Pull the official image and mount the Caddyfile, data, and HTML directories:

docker pull caddy

docker run -p 80:80 -p 443:443 --name caddy \
    -v /mydata/caddy/Caddyfile:/etc/caddy/Caddyfile \
    -v /mydata/caddy/data:/data \
    -v /mydata/caddy/html:/usr/share/caddy \
    -d caddy

Enter the container with docker exec -it caddy /bin/sh to run Caddy commands as on a bare‑metal host.

Conclusion

Caddy’s concise configuration, automatic HTTPS, and rich feature set make it an elegant alternative to Nginx for static hosting, reverse proxying, compression, and more.