Which port gke https loadbalancer use for health checks?

Question

Please I want to know which port GKE uses when performing the health checks of the backend services. Does it use the service port declared in the service yaml or other specific ports? Because I'm having trouble getting the back services healthy.

Answer 1

Google Cloud has special routes for the load balancers and their associated health checks.

Routes that facilitate communication between Google Cloud health check probe systems and your backend VMs exist outside your VPC network, and cannot be removed. However, your VPC network must have ingress allow firewall rules to permit traffic from these systems.

For health checks to work you must create ingress allow firewall rules so that traffic from Google Cloud probers can connect to your backends. You can refer to this documentation.