Example of expressjs middleware

server-with-container.js

const express = require('express')
const morgan = require('morgan')
const helmet = require('helmet')
const bodyparser = require('body-parser')
const cors = require('cors')
const spdy = require('spdy')
const _api = require('../api/booking')

const start = (container) => {
  return new Promise((resolve, reject) => {
    
    // here we grab our dependencies needed for the server
    const {repo, port, ssl} = container.resolve('serverSettings')

    if (!repo) {
      reject(new Error('The server must be started with a connected repository'))
    }
    if (!port) {
      reject(new Error('The server must be started with an available port'))
    }

    const app = express()
    app.use(morgan('dev'))
    app.use(bodyparser.json())
    app.use(cors())
    app.use(helmet())
    app.use((err, req, res, next) => {
      if (err) {
        reject(new Error('Something went wrong!, err:' + err))
        res.status(500).send('Something went wrong!')
      }
      next()
    })
    
    // here is where we register the container as middleware
    app.use((req, res, next) => {
      req.container = container.createScope()
      next()
    })
    
    // here we inject the repo to the API, since the repo is need it for all of our functions
    // and we are using inversion of control to make it available
    const api = _api.bind(null, {repo: container.resolve('repo')})
    api(app)

    if (process.env.NODE === 'test') {
      const server = app.listen(port, () => resolve(server))
    } else {
      const server = spdy.createServer(ssl, app)
        .listen(port, () => resolve(server))
    }
  })
}

module.exports = Object.assign({}, {start})