Caddy configuration for CakePHP 3 (and probably 2 as well) - Use this file on your project root

Caddyfile

localhost:80

root webroot

fastcgi / 127.0.0.1:9000 php

rewrite {
    to {path} {path}/ /index.php?{path}&{query}
}

log logs/server.log {
    rotate {
        size 100
        age 14
        keep 10
    }
}

With modern Caddy and php-fpm (and systemd for logging) this becomes something like this:

localhost:80 {
    root * webroot
    php_fastcgi unix//run/php/php7.4-fpm.sock
    file_server # If you also need to serve static assets
}

If you need to pass additional CGI env vars:

...
    php_fastcgi unix//run/php/php7.4-fpm.sock {
        env TLS_CLIENT_CERT {tls_client_certificate_der_base64}
        env FOO_BAR "baz qux"
    }
...