JWT Example

config.js

module.exports = {
  secret: 'hellowthisismyskret',
  port: process.env.PORT || 9001,
  users: [['test', 'tester'], ['daniel', 'wordpass']]
}

index.js

const jwt = require('jsonwebtoken')
const config = require('./config')
const app = require('express')()

const tokenMiddleware = (req, res, next) => {
  const authHeader = req.headers['authorization']
  let token
  if (authHeader && authHeader.startsWith('Bearer ')) token = authHeader.slice(7, authHeader.length)
  if (token) {
    jwt.verify(token, config.secret, {}, (err, decoded) => {
      if (err) return next(err)
      req.decoded = decoded
      return next()
    })
  } else {
    return next(new Error('Could not find token'))
  }
}

const loginController = (req, res) => {
  const {
    username = '',
    password = ''
  } = req.query
  const requestedUser = config.users.find(usr => usr[0] === username)
  if (requestedUser && requestedUser[1] === password) {
    const token = jwt.sign({ username }, config.secret, {
      expiresIn: '12s'
    })
    res.json({ token })
  } else {
    next(new Error('No user found with those credentials'))
  }
}

app.get('/', (req, res) => res.send('hello world'))
app.get('/api/login', loginController)
app.get('/api/test', tokenMiddleware, (req, res) => {
  res.send({ decoded: req.decoded.username })
})
app.use('/api', (err, req, res, next) => {
  if (err) res.status(403).send({ error: err.toString()})
})

app.listen(config.port, () => console.log(`Now listening on port ${config.port}`))