Way to Health Check from Load Balancer

[jseiser]

Is your feature request related to a problem? Please describe.
There should be a way to determine the health of the VPN from the load balancer. Creating an public NLB in AWS.

Annotations:              
                          service.beta.kubernetes.io/aws-load-balancer-nlb-target-type: ip
                          service.beta.kubernetes.io/aws-load-balancer-scheme: internet-facing
                          service.beta.kubernetes.io/aws-load-balancer-target-group-attributes:
                          service.beta.kubernetes.io/aws-load-balancer-type: external

You end up with a UDP listener like you would expect, but an NLB can only health check via TCP, HTTP, or HTTPS.

https://docs.aws.amazon.com/elasticloadbalancing/latest/network/target-group-health-checks.html

So the service is down and no traffic is routed.

Describe the solution you'd like

Ideally the agent container exposes some sort of healthcheck via HTTP.