Firebase Node.js admin SDK timeouts when trying to access Realtime DB - node.js

Question

Using the Node.js admin SDK with Firebase Functions I get a timeout whenever I try to access the Realtime Database. This occurs only when testing a function locally (firebase serve --only functions,hosting) and when the default app is initialized using the functions.config().firebase.
This is a new behavior that started just a couple a days ago. However, if I try to initialize the default app with the serviceAccount.json file everything works as expected.
I'm using firebase-admin version 4.2.1 and firebase-functions version 0.5.9.
I wrote a straight forward http triggered function that fails due to timeout:
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
const db = admin.database();
exports.testDbConnection = functions.https.onRequest((req, res) => {
return admin.database().ref().once('value')
.then(function(snapshot) {
res.json(snapshot);
}).catch(function(error) {
res.json(error);
});
});

Answer 1

from the documentation
Always end an HTTP function with send(), redirect(), or end(). Otherwise, your function might to continue to run and be forcibly terminated by the system
see https://firebase.google.com/docs/functions/http-events#terminate_http_functions

Answer 2

This might depend on the firebase-tools version that you are using, but looks familiar to this Github issue
The solution for it is to either upgrade to the latest version of the CLI or use the workaround solution:
Go to https://cloud.google.com/console/iam-admin/serviceaccounts
Click “Create service account”, give it a name (e.g. emulator), give it the Project>Owner role.Check “Furnish a new private key”, pick “JSON”.
Save the file somewhere on your computer
Run export GOOGLE_APPLICATION_CREDENTIALS="absolute/path/to/file.json"
Run firebase serve --only functions