How to handle HTTPS with spring-boot after google load balancer has been configured to handle https?

Question

I have gotten the picture that if the google load balancer has been configured to handle HTTPS (by adding SSL certificate) that I don't need to have a ssl certificate on my compute engine instances. From my understanding the load balancer gets the secure request and then just forwards with http to an instance.

Now the frontend for the load balancer is configured for two ports. 8080 for regular HTTP protocol and 443 for HTTPS protocol. If I only want to handle HTTPS is setting the spring-boot application to listen to port 443 the only thing I have to do to make it work? Simply adding the following this to application.properties.

server.port = 443

Or is there more configuration needed from the spring part? I'm genuinely interested in learning this and have researched and tried reading up on this but I can't seem to find any good resources doing something similar. I get the feeling that a lot of the knowledge around these kind of problems is gotten through practical experiences.

Answer 1

If you want the Google load balancer to terminate HTTPS and forward HTTP to your backend services, simply configure the load balancer with a HTTP backend. If you're using a HTTPS backend you'll have to listen to and handle HTTPS traffic in your app.

The difference is if the traffic between the load balancer and your backend (inside GCP) is encrypted or not. usually HTTPS termination at the load balancer level is enough.