Fun stuff. I'd be tempted to either a) run a deployment step to freeze CSS locally or b) do some nginx reverse proxy magic to grab the latest CSS and cache it for a long time (I.e. only grabbing it from GAE once per revision).
That's a fairly consequential thingee to have on a server with availability independent of one's own.
If folks want I'll OSS code for this, although at a dozen lines in Rails it is barely worth typing git clone...
How would I make sure my off-domain images, that are referenced in css, are linked with http when the connection is non-ssl, and https, when the connection is ssl? Currently I make the server link to two separately cached css files (depending on secure or not), which are themselves dynamically generated with an ssl flag.
Instead of specifying http://example.com/foo.png or https://example.com/foo.png, you can just use //example.com/foo.png. AFAIK the only downside to that is older versions of IE (6 & 7 I think) will download the image twice for some reason.
That's a fairly consequential thingee to have on a server with availability independent of one's own.
If folks want I'll OSS code for this, although at a dozen lines in Rails it is barely worth typing git clone...