can I use frankenphp to replace a php-fpm container?

[danhimalplanet]

I have an ubuntu baremetal host. I run caddy on it. I built the caddy binary with xcaddy

I have a php-fpm docker container, I run like so:

services:
    php:
        image: php:8.3.0-fpm-alpine
        volumes:
          - /srv/sites/my-site.com:/var/www/html
        ports:
          - 9000:9000

my caddy config block:

        @my-site host my-site.com
        handle @my-site {
                root * /srv/sites/my-site.com
                php_fastcgi localhost:9000 {
                        root /var/www/html
                }
                file_server
        }

I brought up a frankenphp container:

docker run -d --name frankenphp -v /srv/sites/my-site.com:/app/public \
    -p 9001:80 \
    dunglas/frankenphp

I tried a different block in caddy config:

	@my-site host my-site.com
	handle @my-site {
		root * /srv/sites/my-site.com
                php_fastcgi localhost:9001 {
			root /app/public
	        }	
		file_server
	}

Servers static html just fine. Can't process php files.

Is it possible to do this?

[withinboredom]

Frankenphp doesn't have the same configuration as fastcgi. I recommend checking out the Caddyfile section to see how to configure it.

[danhimalplanet]

I was hoping I could use my existing Caddy configuration and pass through requests for processing php scripts to the frankenphp container, and configure frankenphp in the frankenphp container.

I think what you're saying is I need to replace my existing Caddy binary with a frankenphp caddy container.

[withinboredom]

Yeah. You can do that.

Frankenphp is more akin to mod-php in Apache than fpm so fpm-proxy won't work. Instead you need to use a regular http proxy. Then in your frankenphp config, set the SERVER_NAME to http://localhost:8080 or something.

Basically something like this: