How to get www. custom domain working with GAE and Cloudflare?

[Alex Kerr]

Hi,

I've got a naked (i.e. without 'www.') custom domain working with my App Engine app and I'm using Cloudflare in front of this as a CDN. On Cloudflare I have www.mydomain.com rerouted as a CNAME to mydomain.com. Entering the naked domain in a browser brings up my app as expected. But using www.mydomain.com gives a 404 error from Google. I've read the custom domains docs for App Engine, but still unsure how to configure things and where (e.g. on GAE console, or Cloudflare, or both?), so www. works as well.

I should also mention that I have a Javascript based redirect when my homepage loads from HTTP to HTTPS. Currently https://www.mydomain.com also fails as above.

Thanks for any help!

Alex