Ok, so you’re working with Google App Engine, cool.

It comes time to deploy your application, and of course you’ve created several application copies in your GAE account to have DEV, QA and PROD versions of your app. But how do you manage the app.yaml file which holds the application identifier? (this determines which version is uploaded).

Here’s a simple solution; I have an “upload DEV.bat” file in my root folder that has this simple code:

copy appDEV.yaml app.yaml
appcfg.py update .

When I double click on this file to update my DEV app the script just copies the DEV yaml file to app.yaml and then performs the GAE update. You could replicate this file for every environment you have. Presto.