Hi i tried to publish the syncthing WebGUIs from my DMZ systems to my internaly accessible haproxy VIP on my pfSense firewall and couldn't figure out WHY I can't connect to the service, it seems to have error "503 Server not found" until I choose to use the default backend.
I was stuck for half an hour, this moment as I write this blog entry. I figured out:
HAProxy refers to the first match of the acl per IP in the frontends, NOT WITH THE PORTs in mind. I had to use a different ACL check that matches only this frontend I wanted.