Let #honk support FastCGI so that it can be easily put behind httpd(8) instead of relayd(8).

Example httpd.conf(5) snippet:

server "example.com" {
    listen on egress tls port 443
    tls {
        certificate "/etc/ssl/example.com.fullchain.pem"
        key "/etc/ssl/private/example.com.key"
    }

    location "/*" {
        fastcgi socket tcp 127.0.0.1 8000
    }
}

Start honk with the -fcgi flag.

https://github.com/timkuijsten/honk/tree/fcgi

/cc @tedu