Sample project to connect a GAE app to Firebase.
Requires billing enabled (for Sockets). Requires manual instance scaling (for background threads).
Store firebase secrets in GaeFirebase/src/webapp/secrets.properties
firebaseSecret=<Firebase Secret>
Put Google service account secret in GaeFirebase/src/main/webapp/application_default_credentials.json
Assumes that there is a file named gae-service-account.json located in src/main/webapp/
$ cd GaeFirebase
$ mvn appengine:devserver
$ cd GaeFirebase
$ mvn appengine:update