Caddy

Caddy 2 is a powerful, enterprise-ready web server with automatic HTTPS by default. v2.8 (2025) improves HTTP/3 performance and certificate management.

When to Use

• HTTPS Default: You want zero-config SSL. Caddy obtains and renews certificates automatically.
• Simplicity: Caddyfile is the most human-readable config format.
• Go Apps: Can act as a process manager or library for Go applications.

Quick Start

# Caddyfile
example.com {
    reverse_proxy localhost:3000
    encode zstd gzip
    file_server
}

Core Concepts

Caddyfile

Simple configuration format. directive argument { block }

JSON Config

The native config format. Caddyfile is adapted to JSON. API allows real-time config updates via REST.

Modules

Caddy is extensible. Plugins (like caddy-dns-cloudflare) are compiled in via xcaddy.

Best Practices (2025)

Do:

• Use Caddyfile: For 99% of cases, it's enough.
• Persist /data: Caddy stores certificates in the /data directory. Mount this volume in Docker.
• Use caddy fmt: Auto-format your config.

Don't:

• Don't sit behind another proxy: If you hide Caddy behind Cloudflare/Nginx, you break its ACME challenges unless you configure it specifically.

References

• Caddy Documentation