Enforce HTTPS access if swagger definition disallows http

[surajbarkale]

In our swagger definition, we only have https scheme enabled. However, when testing with Cloud Endpoints for App Engine Flexible, we found that the esp happily accepts http requests and passes on to our service.

Can you please redirect http requests to https if no http access is specified in swagger definition?

[qiwzhang]

It is a reasonable feature request. we can add start_esp flag to add this line in Nginx config

return 301 https://$host$request_uri;

But it is not easy to for FLEX. Users can not use start_esp flags directly.