Error
While moving to kubernetes, and migrating spring boot apps, we encountered a strange behavior that few of the webpages served by freemarker templates in spring boot were adding port :8080 instead of just using the hostname with SSL port :443
Fix
After some investigation and trying to find some workaround, we found out that X-Forwarded-* headers needs to be forwarded by nginx ingress controller when it’s behind an azure app gateway(L7 load balancer).
And nginx ingress controller wasn’t configured to forward the header. So we needed to enable use-forwarded-headers in configmap for nginx configuration.