Change project from Google App Engine Flexible to Standard

Question

I have a Java8 project currently configured to be deployed to GAE Flexible. Having Java8 now available in GAE Standard I would like to change to this (for cost and maintenance reasons plus quicker deploy).

Can anyone point me to the settings to change? Currently seeing Dev App Server does not support App Engine Flexible Environment applications. when running mvn appengine:run. I already checked the app.yaml, appengine-web.xml.

Answer 1

As Dan mentioned, the documentation highlights a lot of the differences.

As for your error, it's likely caused by your application still configured like a Flex app. Make sure you don't have this part:

runtime: python
env: flex

The key here is that the process is less like "migration" and more like "redeploying" or "redesigning" when moving from or to GAE (Google App Engine) standard. The safest way to simply take your code and just deploy to app engine standard from scratch (no existing configuration, just read GAE standard docs and start from there).

GAE standard gives you a lot of builtin access to our resources like Datastore and Cloud SQL, while most of the resource can be accessed from GAE Flex and even GCE (Google Compute Engine) through the use of libraries, it's just a lot easier on GAE standard. So I would recommend looking through the Standard -> Flex migration docs](https://cloud.google.com/appengine/docs/flexible/java/migrating) to get an idea on which APIs are available and how they have changed.