- masterlb is now an extra part of the cluster spec
- ports can now be attached to masterlb by using the 'loadbalancer'
nodefilter
- all ports exposed on the masterlb will be proxied to all master nodes
(on the same port)
Up to now, we exposed ports on single master nodes, which is quite
inconvenient on user side and troublesome on development side.
Now, we're creating a proxy container which exposes a single port
and proxies traffic to all master nodes.
Currently, this only works with 'k3d create cluster' and won't
update the proxy when using 'k3d create node --role master'.
