Google callback url giving back 400 when deployed in heroku - node.js

Question

I developed an app using MEAN framework and used passportjs's google strategy to authenticate. The local run runs fine, but when I deploy the same to heroku, since Heroku runs its app on a random port. I am not sure what google callback url I need to add in my google console's "Authorized redirect URIs".
passport.use(new GoogleStrategy({
clientID: config.googleAuth.clientID,
clientSecret: config.googleAuth.clientSecret,
callbackURL: config.googleAuth.callbackURL
}, function (token, refreshToken, profile, done) {
console.log(token, refreshToken, profile, done);
var query = {
'google.id' : profile.id
};
User.findOne(query, function (err, user) {
if(user){
console.log("User found in the database");
done(null, user);
}
else{
var newUser = new User;
newUser.displayName = profile.displayName;
newUser.image = profile.photos[0].value;
newUser.google = {};
newUser.google.id = profile.id;
newUser.google.token = token;
newUser.save();
console.log("saved user to the database");
done(null, newUser);
}
});
}));
The above shown code is my google strategy. I am using passport-google-oauth lib for authentication.
module.exports = {
development: {
rootPath: rootPath,
db: 'xxx',
port: process.env.PORT || 3030,
googleAuth: {
clientID: 'xxx',
clientSecret: 'xxx',
callbackURL: 'http://localhost:3030/auth/google/callback'
}
},
production: {
rootPath: rootPath,
db: 'xxx',
port: process.env.PORT || 80,
googleAuth: {
clientID: 'xxx',
clientSecret: 'xxxx',
callbackURL: 'https://<myheroku-app>:<heroku-port-no>/auth/google/callback'
}
}
}
The above is the details of my google strategy. The localhost part works fine if I add http://localhost:3030/auth/google/callback to the Authorized redirect URI's. But when I try to do the same for the heroku app, I get a 400 server error with Error: redirect_uri_mismatch as the error.
How do I fix this thing? I am so close to deploying this app and stuck with just this thing. Let me know if you would need any more info.

Answer 1

You need to add heroku domain name and heroku callback url see working example below:

Answer 2

You could use relative paths at callbackURL (eg callbackURL: '/auth/google/callback') to make your code less depended on specific domains, and add an additional element on googleAuth, by putting a comma after callbackURL, as:
proxy: true
After this, you can use https on google's developers console for your callbacks.