Enable multiple kubeapi-load-balancer units by default

[Bui Hong Ha]

Currently [1], canonical-kubernetes has only 1 units of kubeapi-load-balancer by default despite that kubeapi-load-balancer charm supports High Availibity deployment [2]

It would be better if the charm also enable multiple kubeapi-load-balancer units by default. A documentation on how to scale kubeapi-load-balancer is also helpful at first deployment.

# Reference
1. As in revision 677 of canonical-kubernetes charm: https://api.jujucharms.com/charmstore/v5/bundle/canonical-kubernetes-677/archive/bundle.yaml)
2. https://jaas.ai/u/containers/kubeapi-load-balancer/675

[Tim Van Steenburgh (tvansteenburgh)]

Thanks for this - I agree we should increase this to 2 units in the default bundle.

[Tim Van Steenburgh (tvansteenburgh)]

The difficulty with this is that if you have 2 api-loadbalancers, you then need something in front of those so that you have one ingress point to the cluster. There are several options for this which are enumerated here: https://ubuntu.com/kubernetes/docs/high-availability

Which of these options to use depends on where the cluster is being deployed. This means we can't really make a one-size-fits-all bundle. This is why the default bundle today simply has one kube-api-loadbalancer. It's left up to the person deploying to choose the HA solution that works for them, and scale the components as required.