Deploying express and node js app to google app engine - node.js

Question

I have tested my whole app locally and it works perfectly, but the moment I deploy it to google app engine, The entire Oauth2 process by logging in with google stops working. I do not know what the problem is.
One use case I am testing write now is to have a ejs file with a link that says login. If you click on that link it should use google oauth2 to log you in and the page that is shown is your display name (obtained from your google account) after you log in. When I refresh this site, this display name disappears signifying that it has logged out (for some reason) even though it is supposed to stay logged in. On my localhost copy, it works completely, it stays logged in and the display name stays in tact.
const express = require('express');
const Datastore = require('#google-cloud/datastore');
const bodyParser = require('body-parser');
const passport = require('passport');
const session = require('express-session');
const GoogleStrategy = require('passport-google-oauth20').Strategy;
const app = express();
const datastore = Datastore();
app.enable('trust proxy');
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.use(require('cookie-parser')());
const projectId = 'ece6102-guestbookapp';
const GOOGLE_CLIENT_ID = "";
const GOOGLE_CLIENT_SECRET = "";
const Logging = require('#google-cloud/logging');
function getLogEntries () {
// Instantiates a client
const logging = Logging();
const options = {
pageSize: 10,
filter: 'resource.type="cloud_function"'
};
// Retrieve the latest Cloud Function log entries
// See https://googlecloudplatform.github.io/gcloud-node/#/docs/logging
return logging.getEntries(options)
.then(([entries]) => {
console.log('Entries:');
entries.forEach((entry) => console.log(entry));
return entries;
});
}
passport.serializeUser(function(user, done) {
done(null, user);
});
passport.deserializeUser(function(obj, done) {
done(null, obj);
});
// Use the GoogleStrategy within Passport.
// Strategies in Passport require a `verify` function, which accept
// credentials (in this case, an accessToken, refreshToken, and Google
// profile), and invoke a callback with a user object.
passport.use(new GoogleStrategy({
clientID: GOOGLE_CLIENT_ID,
clientSecret: GOOGLE_CLIENT_SECRET,
callbackURL: "/auth/google/callback",
//NOTE :
//Carefull ! and avoid usage of Private IP, otherwise you will get the device_id device_name issue for Private IP during authentication
//The workaround is to set up thru the google cloud console a fully qualified domain name such as http://mydomain:3000/
//then edit your /etc/hosts local file to point on your private IP.
//Also both sign-in button + callbackURL has to be share the same url, otherwise two cookies will be created and lead to lost your session
//if you use it.
passReqToCallback : true
},
function(request, accessToken, refreshToken, profile, done) {
console.log("Calling into this");
// asynchronous verification, for effect...
process.nextTick(function () {
// To keep the example simple, the user's Google profile is returned to
// represent the logged-in user. In a typical application, you would want
// to associate the Google account with a user record in your database,
// and return that user instead.
return done(null, profile);
});
}
));
function insertMessage (message, guestbook, user) {
let mess = 'An anonymous person wrote:';
if (user) {
mess = user.displayName + ' wrote:';
}
return datastore.save({
key: datastore.key(guestbook),
data: {
timestamp: new Date(),
username: mess,
message: message
}
});
}
function getMessages (guestbook) {
const query = datastore.createQuery(guestbook)
.order('timestamp', { descending: true })
.limit(10);
return datastore.runQuery(query)
.then((results) => {
return results[0];
})
.catch((error) => {
});
}
app.set('views', './views');
app.set('view engine', 'ejs');
app.use(express.static('public'));
app.use( session({
secret: 'cookie_secret',
resave: true,
saveUninitialized: true
}));
app.use( passport.initialize());
app.use( passport.session());
app.get('/', (req, res) => {
console.log(req.query);
res.render('index', {
user: req.user
});
// if ('book' in req.query) {
// getMessages(req.query['book']).then((results) => {
// res.render('index', {
// messages: results,
// guestbookname: req.query['book'],
// user: req.user
// });
// });
// } else {
// getMessages('message').then((results) => {
// res.render('index', {
// messages: results,
// guestbookname: 'message',
// user: req.user
// });
// });
// }
});
app.post('/addEntry', (req, res) => {
console.log(req.user);
insertMessage(req.body.entry, req.body.book, req.user)
.then(() => getMessages())
.then((messages) => {
res.redirect('/?book=' + req.body.book);
});
});
app.get('/auth/google', passport.authenticate('google', { scope: [
'https://www.googleapis.com/auth/plus.login']
}));
app.get('/auth/google/callback', passport.authenticate('google'), (req, res) => {
res.redirect('/');
});
app.get('/auth/logout', (req, res) => {
req.logout();
res.redirect('/');
});
const server = app.listen(8080, () => {
const host = server.address().address;
const port = server.address().port;
console.log(`Example app listening at http://${host}:${port}`);
});
This is a copy of the code I have written and some pics as to what its supposed to do:
This the the first image with the login button
This is the second image after logging in