Ingress fails on aws ec2 instance
See also #686 (closed) for the context.
Right now we disable k3s' default load balancer (servicelb) and install metallb per default, because the ingress needed the real client IP to be able to block/allow certain IP ranges (see #660 (closed)).
Unfortunatly, metallb doesn't work with a lot of cloud providers (see https://metallb.universe.tf/installation/clouds).
I propose we switch back to the included k3s servicelb as default, and document how to use metallb in order to be able to get the source IP for blocking/allowing IP ranges.