Discord OAuth2 login with koa

Question

I'm trying to use the koa and passport to login to discord.

I used the examples of koa-passport and passport-discord, but somehow I can't get it to work. It seems that most of it works (I get the accessToken, refreshToken and the profile info), but the redirect after the authentication never happens, the page just shows Not Found.

Using express, everything works.

I think the error is somewhere here, but I tried everything and couldn't get it to work.

router.get('/auth/discord/callback', passport.authenticate('discord', {
  scope: scopes,
  failureRedirect: '/'
}, (err, profile, info) => {
  console.log(err, profile, info);
}), (ctx, next) => {
  console.log('test'); // never executed
});

In koa, the second middleware doesn't get executed, whereas in express it does. But looking at the koa-router docs, it looks like it should.

This is my complete code:

server.js

const Koa = require('koa')
const app = new Koa()
const scopes = ['identify', 'guilds'];

// trust proxy
app.proxy = true

// sessions
const session = require('koa-session')
app.keys = ['your-session-secret']
app.use(session({}, app))

// body parser
const bodyParser = require('koa-bodyparser')
app.use(bodyParser())

// authentication
require('./auth')
const passport = require('koa-passport')
app.use(passport.initialize())
app.use(passport.session())

// routes
const fs = require('fs')
const Router = require('koa-router');

const router = new Router();

app.use((ctx, next) => {
  console.log('url', ctx.url);
  next();
});

router.get('/', function (ctx) {
  ctx.type = 'html'
  ctx.body = fs.createReadStream('server/views/login.html')
})

router.get('/logout', function (ctx) {
  ctx.logout()
  ctx.redirect('/')
})

router.get('/auth/discord', passport.authenticate('discord', {
  scope: scopes
}));
router.get('/auth/discord/callback', passport.authenticate('discord', {
  scope: scopes,
  failureRedirect: '/'
}, (err, profile, info) => {
  console.log(err, profile, info);
}), (ctx, next) => {
  console.log('test'); // never executed
});

// Require authentication for now
app.use(function (ctx, next) {
  if (ctx.isAuthenticated()) {
    return next()
  } else {
    ctx.redirect('/')
  }
})

router.get('/app', function (ctx) {
  ctx.type = 'html'
  ctx.body = fs.createReadStream('server/views/app.html')
})

app.use(router.routes());

// start server
const port = process.env.PORT || 3000
app.listen(port, () => console.log('Server listening on', port))

auth.js

const passport = require('koa-passport')
const configWeb = require('../config_web.json');
const scopes = ['identify', 'guilds'];

passport.serializeUser(function (user, done) {
  done(null, user.id)
})

passport.deserializeUser(async function (id, done) {
  try {
    done(null, {
      id: 1,
      username: 'test'
    })
  } catch (err) {
    done(err)
  }
})

var DiscordStrategy = require('passport-discord').Strategy;

passport.use(new DiscordStrategy({
    clientID: configWeb.discordClientID,
    clientSecret: configWeb.discordClientSecret,
    callbackURL: 'http://localhost:3000/auth/discord/callback',
    scopes: scopes
  },
  function (accessToken, refreshToken, profile, done) {
    console.log(accessToken, refreshToken, profile);
    return done(null, profile);
  }));

Thanks for your help!

Answer 1

I have been trying to use the same modules as you, and thank you for sharing your code as it has helped me fill in the gaps between the documentation for all of these modules.

After playing around with it myself, I think the problem is in this route here:

router.get('/auth/discord/callback', passport.authenticate('discord', {
  scope: scopes,
  failureRedirect: '/'
}, (err, profile, info) => {
  console.log(err, profile, info);
}), (ctx, next) => {
  console.log('test'); // never executed
});

By following this SO answer, I tried changing that route to work like this:

router.get('/auth/discord/callback', async ctx => {
    return passport.authenticate('discord', {scope: scopes, failureRedirect: '/'},
    function(err, user, info, status) {
        console.log('test'); // This gets executed.
        // And now the ctx object is in-scope to be used from the passport callback.
        ctx.redirect('/');
    })(ctx);
});