Applications running on App Engine are expected to listen on 8080. As advised on this doc[1] "The App Engine front end will route incoming requests to the appropriate module on port 8080. You must be sure that your application code is listening on 8080"
[1]https://cloud.google.com/appengine/docs/flexible/custom-runtimes/build#listening_to_port_8080 -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/752d868b-0c88-4c3a-bfc8-bece2f6fdcb7%40googlegroups.com.
