Google App Engine - one datastore for different domains and apps

Question

Is that somehow possible to access one datastore? Or access one app from different domains.

Answer 1

Every app has its own datastore and memcache (shared among all versions of that app). It seems not possible to share datastores between applications right now (unless you provide some web service for that), but that would be a nice feature to have, so maybe you should file a feature request with Google vote for it.

As for domains, you can associate your app with domains managed by Google Apps. Multiple domains for the same application should be no problem (except for SSL certificates).

Answer 2

Every version of an app is backed by the same datastore. If you want to limit access for individual requests, you'll need to add a field to your model to enforce that restriction. There are low level hooks in the datastore API for this sort of thing, if you want to go that far.

And yes, you can add a single App Engine app to multiple domains - even in multiple Apps accounts.

Answer 3

You can have multiple versions running at the same time as stated here:

You could create two different apps that run simultaneously; they would each share the same database and memcache.

In the app.yml file just specify version: 1 and version: 2

They would have two different urls:

• http://1.latest.myapp.appspot.com
• http://2.latest.myapp.appspot.com

Using Domain masking, you could then direct from:

• www.myapp.com => http://1.latest.myapp.appspot.com
• www.myapp2.com => http://2.latest.myapp.appspot.com

Answer 4

Kyle's solution would work, but App Engine was never designed to be used in this way. So if you architect your app(s) to rely on this kind of setup and Google clamps down for whatever reason then you'd be screwed.

Answer 5

You can have multitenancy using the Namespace Java API