caddyserver / caddy

Every site on HTTPS

Caddy is an extensible server platform that uses TLS by default.

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• Features
• Build from source
  • For development
  • With version information and/or plugins
• Quick start
• Overview
• Full documentation
• Getting help
• About

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Features

• Easy configuration with the Caddyfile
• Powerful configuration with its native JSON config
• Dynamic configuration with the JSON API
• Config adapters if you don't like JSON
• Automatic HTTPS by default
  • Let's Encrypt for public sites
  • Fully-managed local CA for internal names & IPs
  • Can coordinate with other Caddy instances in a cluster
• Stays up when other servers go down due to TLS/OCSP/certificate-related issues
• HTTP/1.1, HTTP/2, and experimental HTTP/3 support
• Highly extensible modular architecture lets Caddy do anything without bloat
• Runs anywhere with no external dependencies (not even libc)
• Written in Go, a language with higher memory safety guarantees than other servers
• Actually fun to use
• So, so much more to discover

Build from source

Requirements:

• Go 1.14 or newer

For development

$ git clone "https://github.com/caddyserver/caddy.git"
$ cd caddy/cmd/caddy/
$ go build

Note: These steps will not embed proper version information. For that, please follow the instructions below.

With version information and/or plugins

Using our builder tool...

$ xcaddy build

...the following steps are automated:

1. Create a new folder: mkdir caddy
2. Change into it: cd caddy
3. Copy Caddy's main.go into the empty folder. Add imports for any custom plugins you want to add.
4. Initialize a Go module: go mod init caddy
5. (Optional) Pin Caddy version: go get github.com/caddyserver/caddy/v2@TAG replacing TAG with a git tag or commit.
6. (Optional) Add plugins by adding their import: _ "IMPORT_PATH"
7. Compile: go build

Quick start

The Caddy website has documentation that includes tutorials, quick-start guides, reference, and more.

We recommend that all users do our Getting Started guide to become familiar with using Caddy.

If you've only got a minute, the website has several quick-start tutorials to choose from! However, after finishing a quick-start tutorial, please read more documentation to understand how the software works. 🙂

Overview

Caddy is most often used as an HTTPS server, but it is suitable for any long-running Go program. First and foremost, it is a platform to run Go applications. Caddy "apps" are just Go programs that are implemented as Caddy modules. Two apps -- tls and http -- ship standard with Caddy.

Caddy apps instantly benefit from automated documentation, graceful on-line config changes via API, and unification with other Caddy apps.

Although JSON is Caddy's native config language, Caddy can accept input from config adapters which can essentially convert any config format of your choice into JSON: Caddyfile, JSON 5, YAML, TOML, NGINX config, and more.

The primary way to configure Caddy is through its API, but if you prefer config files, the command-line interface supports those too.

Caddy exposes an unprecedented level of control compared to any web server in existence. In Caddy, you are usually setting the actual values of the initialized types in memory that power everything from your HTTP handlers and TLS handshakes to your storage medium. Caddy is also ridiculously extensible, with a powerful plugin system that makes vast improvements over other web servers.

To wield the power of this design, you need to know how the config document is structured. Please see the our documentation site for details about Caddy's config structure.

Nearly all of Caddy's configuration is contained in a single config document, rather than being scattered across CLI flags and env variables and a configuration file as with other web servers. This makes managing your server config more straightforward and reduces hidden variables/factors.

Full documentation

Our website has complete documentation:

https://caddyserver.com/docs/

The docs are also open source. You can contribute to them here: https://github.com/caddyserver/website

Getting help

• We strongly recommend that all professionals or companies using Caddy get a support contract through Ardan Labs before help is needed.

• Individuals can exchange help for free on our community forum at https://caddy.community. Remember that people give help out of their spare time and good will. The best way to get help is to give it first!

Please use our issue tracker only for bug reports and feature requests, i.e. actionable development items (support questions will usually be referred to the forums).

About

The name "Caddy" is trademarked. The name of the software is "Caddy", not "Caddy Server" or "CaddyServer". Please call it "Caddy" or, if you wish to clarify, "the Caddy web server". Caddy is a registered trademark of Light Code Labs, LLC.

• Project on Twitter: @caddyserver
• Author on Twitter: @mholt6