Update examples to use external hostname on AWS

[klingerf]

Problem

Kubernetes' LoadBalancerIngress object contains both an ip and a hostname field. GKE sets the ip field, but DNS-based ingress (AWS loadblancers) set the hostname field. All of our existing examples in the k8s-daemonset dir assume that ip is set, and ignore the hostname field.

Solution

Update our examples with a jsonpath syntax that will read either ip or hostname, depending upon which one is set.

Aside

In testing these changes, I realized that we were unnecessarily setting the hostPort option on ports that do not need to have fixed port on the node where they are running. I've removed that where it's appropriate.

Fixes #78.

[esbie]

lgtm