How to permanently redirect `http://` and `www.` URLs to `https://`?

So you can add "secure: always" to your yaml file

https://cloud.google.com/appengine/docs/python/config/appconfig?hl=en#Python_app_yaml_Secure_URLs

For the sake of completeness. The Java way is to set the transport guarantee to confidential like this.

<security-constraint>
  <web-resource-collection>
    <web-resource-name>profile</web-resource-name>
    <url-pattern>/profile/*</url-pattern>
  </web-resource-collection>
  <user-data-constraint>
    <transport-guarantee>CONFIDENTIAL</transport-guarantee>
  </user-data-constraint>
</security-constraint>

You can also find this here in the documentation.

(For Node at least,) in your app.yaml, add the following:

handlers:
- url: /.*
  secure: always
  redirect_http_response_code: 301
  script: auto

Reference: https://cloud.google.com/appengine/docs/standard/nodejs/config/appref