Common Caddyfile Patterns

This page demonstrates a few complete and minimal Caddyfile configurations for common use cases. These can be helpful starting points for your own Caddyfile documents.

These are not drop-in solutions; you will have to customize your domain name, ports/sockets, directory paths, etc. They are intended to illustrate some of the most common configuration patterns.

Static file server
Reverse proxy
PHP
Redirect www. subdomain
Trailing slashes
Wildcard certificates
Single-page apps (SPAs)
Caddy proxying to another Caddy

Static file server

example.com {
	root * /var/www
	file_server
}

As usual, the first line is the site address. The root directive specifies the path to the root of the site (the * means to match all requests, so as to disambiguate from a path matcher)—change the path to your site if it isn't the current working directory. Finally, we enable the static file server.

Reverse proxy

Proxy all requests:

example.com {
	reverse_proxy localhost:5000
}

Only proxy requests having a path starting with /api/ and serve static files for everything else:

example.com {
	root * /var/www
	reverse_proxy /api/* localhost:5000
	file_server
}

This uses a request matcher to match only requests that start with /api/ and proxy them to the backend. All other requests will be served from the site root with the static file server. This also depends on the fact that reverse_proxy is higher on the directive order than file_server.

There are many more reverse_proxy examples here.

PHP

PHP-FPM

With a PHP FastCGI service running, something like this works for most modern PHP apps:

example.com {
	root * /srv/public
	encode
	php_fastcgi localhost:9000
	file_server
}

Customize the site root accordingly; this example assumes that your PHP app's webroot is within a public directory—requests for files that exist on disk will be served with file_server, and anything else will be routed to index.php for handling by the PHP app.

You may sometimes use a unix socket to connect to PHP-FPM:

php_fastcgi unix//run/php/php8.2-fpm.sock

The php_fastcgi directive is actually just a shortcut for several pieces of configuration.

FrankenPHP

Alternatively, you may use FrankenPHP, which is a distribution of Caddy which calls PHP directly using CGO (Go to C bindings). This can be up to 4x faster than with PHP-FPM, and even better if you can use the worker mode.

{
    frankenphp
    order php_server before file_server
}

example.com {
	root * /srv/public
    encode zstd br gzip
    php_server
}

Redirect `www.` subdomain

To add the www. subdomain with an HTTP redirect:

example.com {
	redir https://www.{host}{uri}
}

www.example.com {
}

To remove it:

www.example.com {
	redir https://example.com{uri}
}

example.com {
}

To remove it for multiple domains at once; this uses the {labels.*} placeholders which are the parts of the hostname, 0-indexed from the right (e.g. 0=com, 1=example-one, 2=www):

www.example-one.com, www.example-two.com {
	redir https://{labels.1}.{labels.0}{uri}
}

example-one.com, example-two.com {
}

Trailing slashes

You will not usually need to configure this yourself; the file_server directive will automatically add or remove trailing slashes from requests by way of HTTP redirects, depending on whether the requested resource is a directory or file, respectively.

However, if you need to, you can still enforce trailing slashes with your config. There are two ways to do it: internally or externally.

Internal enforcement

This uses the rewrite directive. Caddy will rewrite the URI internally to add or remove the trailing slash:

example.com {
	rewrite /add     /add/
	rewrite /remove/ /remove
}

Using a rewrite, requests with and without the trailing slash will be the same.

External enforcement

This uses the redir directive. Caddy will ask the browser to change the URI to add or remove the trailing slash:

example.com {
	redir /add     /add/
	redir /remove/ /remove
}

Using a redirect, the client will have to re-issue the request, enforcing a single acceptable URI for a resource.

Wildcard certificates

For most issuers including Let's Encrypt, you must enable the ACME DNS challenge to have Caddy automate wildcard certificates.

With the DNS challenge enabled, as of Caddy 2.10, Caddy will prefer an applicable wildcard certificate that is already configured or managed before managing a separate certificate for a subdomain.

If you need to serve multiple subdomains with the same wildcard certificate, the best way to handle them is with a Caddyfile like this, making use of the handle directive and host matchers:

*.example.com {
	tls {
		dns <provider_name> [<params...>]
	}

	@foo host foo.example.com
	handle @foo {
		respond "Foo!"
	}

	@bar host bar.example.com
	handle @bar {
		respond "Bar!"
	}

	# Fallback for otherwise unhandled domains
	handle {
		abort
	}
}

You must enable the ACME DNS challenge to have Caddy automatically manage wildcard certificates.

Single-page apps (SPAs)

When a web page does its own routing, servers may receive lots of requests for pages that don't exist server-side, but which are renderable client-side as long as the singular index file is served instead. Web applications architected like this are known as SPAs, or single-page apps.

The main idea is to have the server "try files" to see if the requested file exists server-side, and if not, fall back to an index file where the client does the routing (usually with client-side JavaScript).

A typical SPA config usually looks something like this:

example.com {
	root * /srv
	encode
	try_files {path} /index.html
	file_server
}

If your SPA is coupled with an API or other server-side-only endpoints, you will want to use handle blocks to treat them exclusively:

example.com {
	encode

	handle /api/* {
		reverse_proxy backend:8000
	}

	handle {
		root * /srv
		try_files {path} /index.html
		file_server
	}
}

If your index.html contains references to your JS/CSS assets with hashed filenames, you may want to consider adding a Cache-Control header to instruct clients to not cache it (so that if the assets change, browsers fetch the new ones). Since the try_files rewrite is used to serve your index.html from any path that doesn't match another file on disk, you can wrap the try_files with a route so that the header handler runs after the rewrite (it normally would run before due to the directive order):

route {
	try_files {path} /index.html
	header /index.html Cache-Control "public, max-age=0, must-revalidate"
}

Caddy proxying to another Caddy

If you have one Caddy instance publicly accessible (let's call it "front"), and another Caddy instance in your private network (let's call it "back") serving your actual app, you can use the reverse_proxy directive to pass requests through.

Front instance:

foo.example.com, bar.example.com {
	reverse_proxy 10.0.0.1:80
}

Back instance:

{
	servers {
		trusted_proxies static private_ranges
	}
}

http://foo.example.com {
	reverse_proxy foo-app:8080
}

http://bar.example.com {
	reverse_proxy bar-app:9000
}

This example serves two different domains, proxying both to the same back Caddy instance, on port 80. Your back instance is serving the two domains different ways, so it's configured with two separate site blocks.
On the back, http:// is used to accept HTTP on port 80. The front instance terminates TLS, and the traffic between front and back are on a private network, so there's no need to re-encrypt it.
You may use a different port like 8080 on the back instance if you need to; just append :8080 to each site address on the back's config, OR set the http_port global option to 8080.
On the back, the trusted_proxies global option is used to tell Caddy to trust the front instance as a proxy. This ensures the real client IP is preserved.
Going further, you could have more than one back instance that you load balance between. You could set up mTLS (mutual TLS) using the acme_server on the front instance such that it acts like the CA for the back instance (useful if the traffic between front and back cross untrusted networks).