auth.js

// http://passportjs.org/

var passport = require('koa-passport')

var user = { id: 1, username: 'test' }

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

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

var LocalStrategy = require('passport-local').Strategy
passport.use(new LocalStrategy(function(username, password, done) {
  // retrieve user ...
  if (username === 'test' && password === 'test') {
    done(null, user)
  } else {
    done(null, false)
  }
}))

var DoubanStrategy = require('passport-douban').Strategy
passport.use(new DoubanStrategy({
    clientID: '01b42bcb7d5ef3de051c8362781cdb9a',
    clientSecret: '8c6cb3c773a5017d',
    callbackURL: 'http://localhost:' + (process.env.PORT || 3000) + '/auth/douban/callback'
  },
  function(accessToken, refreshToken, profile, done) {
    // retrieve user ...
    done(null, user)
  }
))