initialize firebase app in multiple files with nodejs

Question

I want to Initialize Firebase App in multiple files to organize my methods properly, but I not sure which is the best way to do so.

Below is the file system structure:

/functions
 |-keys
 |-methods
 |  |-email.js
 |  |-logger.js
 |-node_modules
 |-index.js
 |-package.json
 |-package-lock.json

In my index.js, I initialize 2 projects where 1 is for production and another is for OTE.:

const functions = require('firebase-functions');
var firebaseAdmin = require('firebase-admin');

var productionServiceAccount = require('./keys/production-key.json');
var oteServiceAccount = require("./keys/ote-key.json");

var prodServer = firebaseAdmin.initializeApp({
    credential: firebaseAdmin.credential.cert(productionServiceAccount),
    databaseURL: 'https://production-panel.firebaseio.com'
}, "prod");
var oteServer = firebaseAdmin.initializeApp({
    credential: firebaseAdmin.credential.cert(oteServiceAccount),
    databaseURL: "https://ote-panel.firebaseio.com"
}, "ote");

console.log("prodServer: ", prodServer.name, "oteServer: ", oteServer.name)

var mailer = require('./methods/email.js') //import code from method folder
var logger = require('./methods/logger.js') //import code from method folder

Below is how i handle the request whether use prod or OTE project:

let admin = req.headers.env == 'prod' ? prodServer : oteServer

Now the problem is my ./methods/logger.js want to read/write log into DB as well, but I don't know how/what to do.

Below is the `logger.js` code:
var exports = {}

exports.log = function(item, ref, env) {
    let admin = env == 'prod' ? prodServer : oteServer //<--problem here

    return admin.database().ref(ref).push(item)
}

module.exports = exports

Should I initialize firebase project again or import it from index.js?

-If initialize firebase project again it will say the project "name" has been used.

-If import it from index.js, then I have to export it from index.js, which when I deploy it to Firebase Function, it will become an onCall Methods..?

-If I move the initialize to another file (./method/initFirebase.js) and import it to index.js when I deploy it to Firebase Function, will it automatically initialize the firebase app?

Please advise. Thank you.

Answer 1

You can create one additional file like you said initFirebase.js and put your initilization and export code there.

const prodServer = firebaseAdmin.initializeApp({
    credential: firebaseAdmin.credential.cert(productionServiceAccount),
    databaseURL: 'https://production-panel.firebaseio.com',
}, 'prod');
const oteServer = firebaseAdmin.initializeApp({
    credential: firebaseAdmin.credential.cert(oteServiceAccount),
    databaseURL: 'https://ote-panel.firebaseio.com',
}, 'ote');
module.exports = {
    firebaseApp: env === 'prod' ? prodServer : oteServer,
};

And from all other file import firebase app

const firebaseApp = require('../YOUR_initFirebase.js')

So you dont need to worry about environment in each of the files and it is working for me on google cloud functions.