HTTPS server

sudo apt install apache2

Modify configuration file

sudo nano /etc/apache2/apache2.conf

Add these lines at the end

# Patching error AH00558
ServerName 127.0.0.1

Enable additional modules

sudo a2enmod headers remoteip rewrite proxy proxy_fcgi

And restart Apache

sudo systemctl reload apache2

On the firewall / gateway

Temporarily Connected on baggins as mountdoom, edit Caddy configuration

sudo nano /etc/caddy/Caddyfile

Add this entry at the end of the file

pixelfed.cogip.be {
    reverse_proxy 192.168.10.60 {
        header_up X-Forwarded-Proto {scheme}
        header_up X-Forwarded-For {remote}
        header_up X-Forwarded-Host {host}
    }
}

And reload

sudo systemctl reload caddy

End of configuring firewall / gateway