This is a very simple project than takes a war file and uploads it to Google App Engine
It's designed to be drop-in deploy stage in your build pipeline. The input is a war file and one property file dropped into the artifacts folder.
For example:
artifacts/foo.war
artifacts/deploy.properties
And deploy.properties contains
deploy.name=foo-appid
deploy.war=foo.war
Then just setup your build pipeline to trigger this project and supply your deploy.username
and deploy.password
as properties.
If you want more control then use the appcfg task directly.