在 Heroku 上实时部署时，passport google oauth2 会导致“内部服务器错误”

Question

I am connected to mongoDB via mongoose and there is no error when using my app on localhost, however when I deployed it onto Heroku I am getting an internal server error.

Here are my js codes:

require("dotenv").config();
const express = require("express");
const bodyParser = require("body-parser");
const ejs = require("ejs");
const mongoose = require("mongoose");
const session = require("express-session");
const passport = require("passport");
const passportLocalMongoose = require("passport-local-mongoose");
const GoogleStrategy = require("passport-google-oauth20").Strategy;
const findOrCreate = require("mongoose-findorcreate");

const app = express();

app.use(express.static("public"));
app.use(bodyParser.urlencoded({extended: true}));
app.set("view engine", "ejs");

app.use(session({
  secret: varkey,
  resave: false,
  saveUninitialized: false
}));

app.use(passport.initialize());
app.use(passport.session());

mongoose.connect("mongodb+srv://admin-name:password@cluster0-7monv.mongodb.net/userDB?retryWrites=true&w=majority", {useNewUrlParser: true, useUnifiedTopology: true});
mongoose.set("useCreateIndex", true);

const userSchema = new mongoose.Schema({
  email: String,
  password: String,
  googleId: String
});

userSchema.plugin(passportLocalMongoose);
userSchema.plugin(findOrCreate);

const User = new mongoose.model("User", userSchema);

passport.use(User.createStrategy());
passport.serializeUser(function(user, done) {
  done(null, user.id);
});

passport.deserializeUser(function(id, done) {
  User.findById(id, function(err, user) {
    done(err, user);
  });
});

passport.use(new GoogleStrategy({
  clientID: process.env.GOOGLE_CLIENT_ID,
  clientSecret: process.env.GOOGLE_CLIENT_SECRET,
  callbackURL: "https://herokudomain.herokuapp.com/auth/google/callback",
},
  function(accessToken, refreshToken, profile, cb) {
    User.findOrCreate({ googleId: profile.id }, function (err, user) {
      return cb(err, user);
    });
  }
));

app.get("/auth/google", passport.authenticate("google", {scope : ["profile", "email"]}));

app.get("/auth/google/callback",
  passport.authenticate("google", { failureRedirect: "/login" }),
  function(req, res) {

    res.redirect("/");
});

And these are my html codes:

<a class="btn" href="/auth/google" role="button">Sign Up with Google</a>

The Heroku log shows this in their error log:

2020-06-09T04:05:10.523711+00:00 app[web.1]: MongoError: E11000 duplicate key error collection: userDB.users index: username_1 dup key: { username: null }
2020-06-09T04:05:10.523722+00:00 app[web.1]:     at Function.create (/app/node_modules/mongodb/lib/core/error.js:51:12)
2020-06-09T04:05:10.523722+00:00 app[web.1]:     at toError (/app/node_modules/mongodb/lib/utils.js:149:22)
2020-06-09T04:05:10.523723+00:00 app[web.1]:     at /app/node_modules/mongodb/lib/operations/common_functions.js:265:39
2020-06-09T04:05:10.523723+00:00 app[web.1]:     at handler (/app/node_modules/mongodb/lib/core/sdam/topology.js:913:24)
2020-06-09T04:05:10.523724+00:00 app[web.1]:     at /app/node_modules/mongodb/lib/cmap/connection_pool.js:356:13
2020-06-09T04:05:10.523724+00:00 app[web.1]:     at handleOperationResult (/app/node_modules/mongodb/lib/core/sdam/server.js:489:5)
2020-06-09T04:05:10.523725+00:00 app[web.1]:     at MessageStream.messageHandler (/app/node_modules/mongodb/lib/cmap/connection.js:270:5)
2020-06-09T04:05:10.523726+00:00 app[web.1]:     at MessageStream.emit (events.js:315:20)
2020-06-09T04:05:10.523726+00:00 app[web.1]:     at processIncomingData (/app/node_modules/mongodb/lib/cmap/message_stream.js:144:12)
2020-06-09T04:05:10.523726+00:00 app[web.1]:     at MessageStream._write (/app/node_modules/mongodb/lib/cmap/message_stream.js:42:5)
2020-06-09T04:05:10.523727+00:00 app[web.1]:     at writeOrBuffer (_stream_writable.js:352:12)
2020-06-09T04:05:10.523727+00:00 app[web.1]:     at MessageStream.Writable.write (_stream_writable.js:303:10)
2020-06-09T04:05:10.523728+00:00 app[web.1]:     at TLSSocket.ondata (_stream_readable.js:712:22)
2020-06-09T04:05:10.523728+00:00 app[web.1]:     at TLSSocket.emit (events.js:315:20)
2020-06-09T04:05:10.523729+00:00 app[web.1]:     at addChunk (_stream_readable.js:302:12)
2020-06-09T04:05:10.523729+00:00 app[web.1]:     at readableAddChunk (_stream_readable.js:278:9)

While the web app returns an "internal server error" page. It seems like they are saying that my database has a duplicate but I've cleared out my database and there is nothing in there anymore.

Please help me, I'm rather new to programming so I'm still learning how to read error codes and understand them so that I can debug myself.

I've seen similar questions and tried solutions that were offered but none of them work in my case that is why I decided to open this question.

Answer 1

Why you are having the error:

From the error logs:

2020-06-09T04:05:10.523711+00:00 app[web.1]: MongoError: E11000 duplicate key error collection: userDB.users index: username_1 dup key: { username: null }
...

I can deduce that you have a unique index on a username field in the users collection and because you have an existing document where the username field is empty(null), MongoDB is preventing you from inserting another document with empty username value.

From the code you posted, I can see the User schema does not include a username field, perhaps you used to have it in the schema before. You should note that depending on how you clear the data in the database, the indexes might or might not be cleared, in this case, the index on the username field wasn't cleared.

The fix:

Drop the index on the username property. Run db.users.dropIndex("username_1") in the mongo CLI to do that. You can run db.users.getIndexes() afterwards to be sure that indexes only exist where you need them.

Answer 2

Since according to MongoDB it thinks that username is unique not letting null value get into the database second time. You need to send the username when you fetch profile from google. My code is the following

    (accessToken, refreshToken, profile, cb) => {
        console.log(profile);
        //install and require find or create to make following function work
        User.findOrCreate({
            googleId: profile.id,
            username: profile.emails[0].value
        }, (err, user) => {
            return cb(err, user);
        });
    }
));