kubernetes LoadBalancer appProtocol

Typically, you set the protocol for the Service to TCP and add an annotation (usually specific to your cloud provider) that configures the load balancer to handle traffic at the HTTP level. This configuration might also include serving HTTPS (HTTP over TLS) and reverse-proxying plain HTTP to your workload.

You might additionally want to specify that the application protocol of the connection is http or https. Use http if the session from the load balancer to your workload is HTTP without TLS, and use https if the session from the load balancer to your workload uses TLS encryption.

https://kubernetes.io/docs/reference/networking/service-protocols/

The appProtocol field provides a way to specify an application protocol for each Service port. This is used as a hint for implementations to offer richer behavior for protocols that they understand.

https://kubernetes.io/docs/concepts/services-networking/service/#application-protocol