It's the firebase API template in Nodejs server side, and also continuous fetching iot sensor data from the firebase.

nodejs_firebase_iot_fetch_data.js

/*
 * author : jiankaiwang
 * platform : nodejs
 * feature : the firebase API template in NodeJS server side
 * description : continuously fetch iot sensor data from the firebase
 * reference : push data into firebase (https://gist.github.com/jiankaiwang/635f40bb5609033e922337b7aa2a44e6)
 */
var firebase = require("firebase");

// firebase configuration
var config = {
    apiKey : "",
    authDomain : "",
    databaseURL : "https://xxx.firebaseio.com/"
    storageBucket : ""
}
firebase.initializeApp(config);
var db = firebase.database();

// Get the key list of the dictionary.
var getDictionaryKeyList = function(getDictObj) {
	var keyList = [];
	for(var key in getDictObj) {
		keyList.push(key);
	}
	return keyList;
}

// Get the value from the firebase.
var ref = db.ref("/cluster1/dev1");
ref.once("value", function(data) {
    // output format is json-encoded
    console.log(data.val());
    // example to get the whole key
    console.log(getDictionaryKeyList(data.val()));
    // end nodejs application
    process.exit();
});