Is there a way to bootstrap an Express app? - express

I'm building an app in Express but I'd like it to call out to S3 to retrieve some keys before the server actually starts up. Is this possible in Express? If I google bootstrap Express I get hits for setting up Express with twitter Bootstrap.
I have used Sails.js before and you could specify bootstrap configurations in a bootstrap.js file so I guess I'm looking for something similar. Otherwise are there alternatives?
I have a index.js file and a separate bin/www file which calls the index.js file. I'd like the bootstrapping done in index.js so that it's included as part of the tests. Right now I 'initialize' the bootstrap but as it's asynchronous the server is already up and running before the bootstrap has complete (or errored out) i.e.
import express from 'express';
import {initializeFromS3} from './services/initializerService';
import healthCheckRouter from './routes/healthCheckRouter';
import bodyParser from 'body-parser';
initializeFromS3(); // Calls out to S3 and does some bootstrapping of configurations
const app = express();
app.use(bodyParser.json()); // to support JSON-encoded bodies
app.use(bodyParser.urlencoded({ // to support URL-encoded bodies
extended: true
}));
// ---------------------------- Routes ----------------------------
app.use('/', express.static('dist/client/'));
app.use('/health-check', healthCheckRouter);
export default app;

Posting my solution for anyone who comes across the same and has a mind blank. I kept the bin/www and index.js files separately but had the express object returned from index.js via a method. Solution below thanks to the friendly people of Github.
Index.js file:
import express from 'express';
import {initialize} from './services/appService';
import healthCheckRouter from './routes/healthCheckRouter';
import loginRouter from './routes/loginRouter';
export function getExpress() {
return initialize()
.then(() => {
const app = express();
// ---------------------------- Routes ----------------------------
app.use('/', express.static('dist/client/'));
app.use('/login', loginRouter);
app.use('/health-check', healthCheckRouter);
return app;
})
}
bin/www file:
import winston from 'winston';
import bodyParser from 'body-parser';
import {getExpress} from '../index';
getExpress()
.then(app => {
app.use(bodyParser.json()); // to support JSON-encoded bodies
app.use(bodyParser.urlencoded({ // to support URL-encoded bodies
extended: true
}));
const port = 3002;
app.listen(port, () => {
winston.info(`Server listening on port ${port}!`);
});
})
.catch(err => {
winston.error('Error starting server', err);
});
Integration tests:
import request from 'supertest';
import {getExpress} from '../../index'
describe('/login integration test', () => {
let app = null;
beforeEach(done => {
getExpress()
.then(res => {
app = res;
done();
});
});
describe('GET /login', () => {
it('should return 400 error if \'app\' is not provided as a query string', done => {
request(app)
.get('/login')
.expect(400, done);
});
});
});

Related

Access privateRuntimeConfig in express server

I've installed the express-nuxt template and I was wondering how could I get access to the privateRuntimeConfig inside nuxt.config.js from express (API folder). One approach I thought about was to put the vars inside a .env file and then installing the dotenv package for the express server, but I think that using just Nuxt could be better.
We have done precisely this by importing the Nuxt config into the file that configures the Express app, and using defu to combine public and private runtime configs, as Nuxt itself does:
// nuxt.config.js
export default {
publicRuntimeConfig: {},
privateRuntimeConfig: { redis: { url: process.env['REDIS_URL'] } }
};
// api/index.js
import express from 'express';
import defu from 'defu';
import { createClient as createRedisClient } from 'redis';
const app = express();
import nuxtConfig from '../nuxt.config.js';
let runtimeConfig;
app.use((req, res, next) => {
if (!runtimeConfig) {
// Load Nuxt config once, at runtime
runtimeConfig = defu(nuxtConfig.privateRuntimeConfig, nuxtConfig.publicRuntimeConfig);
}
next();
});
// Subsequent middlewares will then be able to read from `runtimeConfig`
app.use((req, res, next) => {
const redisClient = createRedisClient({ url: runtimeConfig.redis.url });
next();
});
export default app;

TypeError: bodyParser.json is not a function in nuxt.js

I have received an error message stating: TypeError: bodyParser.json is not a function. My nuxt.config.js file has the following details regarding bodyparser (I originally had const bodyParser = require('body-parser') but an error appeared telling me that I had to use 'import' instead of 'require' so I changed it to 'import('body-parser'):
const bodyParser = import('body-parser')
export default {
serverMiddleware: [
bodyParser.json(),
'~/api'
]
}
In my index.js file under the api folder, I have the following code:
const express = require('express')
const bodyParser = require('body-parser')
const router = express.Router()
const app = express()
router.use((req, res, next) => {
Object.setPrototypeOf(req, app.request)
Object.setPrototypeOf(res, app.response)
req.res = res
res.req = req
next()
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: true }))
})
router.post('/track-data', (req, res) => {
console.log('Stored data!', req.body.data)
res.status(200).json({ message: 'Success!' })
})
module.exports = {
path: '/api',
handler: router
}
Does anyone know how to get this to run? Everytime I enter 'npm run dev' in the terminal, I get the error 'TypeError: bodyParser.json is not a function'.
I had a slightly similar issue and could solve it with this code, first i imported express in the config file, before i did it like you, with bodyParser, but got a deprecated warning, then i use it in the api folder, in the index file, like so:
// nuxt.config.js
import express from 'express';
export default {
ssr: true,
.......,
.......,
serverMiddleware: [
express.json(),
// Api middleware
{ path: '/api', handler: '~/api/index.js' },
]
}
// ~/api/index.js
// Router setup for serverMiddleware
router.use((req, res, next) => {
Object.setPrototypeOf(req, app.request);
Object.setPrototypeOf(res, app.response);
req.res = res;
res.req = req;
next();
});
export default {
path: '/api',
handler: router
};
hope it helps ! 👍
I'm not familiar with nuxtjs specifically, but after looking at the nuxtjs module export docs it looks like your require inside your index.js should be a path to the file, rather than just the string body-parser which I have to imagine just gets processed something like an npm module if no path is supplied.
Additionally, at least in NodeJS and per the MDN docs on export and import, the syntax to import something that's exported with export default is import { destructuredModuleName } from 'string/representing/relative/or/absolute/path/to/module'
or
import * as whatYouWantToCallTheObject from 'string/representing/relative/or/absolute/path/to/module' would give you a more traditional module object with properties/methods matching properties on the exported module.
This should fix it:
import bodyParser from 'body-parser'
You actually used the import() as a dynamic import. It returned a promise which didn't have the json property. Therefore, the error was displayed.

Why Morgan Logger server middleware doesn't work in separate file?

I am following this tutorial in my nextjs app for adding a new middleware for logging so I have the following code in my server.js:
// create a write stream (in append mode)
const accessLogStream = fs.createWriteStream(path.join(__dirname, 'access.log'), { flags: 'a' })
// setup the logger
server.use(morgan('combined', { stream: accessLogStream }))
And it is working without a problem.
But I want to have the logic in a separate file in the middleware directory so I have :
middlewares/logger/index.js
import morgan from "morgan";
import fs from 'fs';
import path from 'path';
export default (req, res, next) => {
var accessLogStream = fs.createWriteStream(path.join(__dirname, 'access.log'), { flags: 'a' })
return morgan('combined', { stream: accessLogStream });
};
and in my server.js I will have: (after importing and initializing stuff)
server.use(logger);
server.use(othermiddlewareone);
server.use(othermiddlewaretwo);
The other middlewares are working fine but this one breaks. Do you know why is that?
I changed the middleware like this and now it is working fine :)
import type { Request, Response, Next } from './types';
import morgan from "morgan";
import fs from 'fs';
import path from 'path';
const accessLogStream = fs.createWriteStream(path.join(__dirname, 'server.log'), { flags: 'a' })
const logger = morgan('combined', { stream: accessLogStream })
export default async (req: Request, res: Response, next: Next) => {
logger(req, res, function (err) {
return next();
})
};

error hanlders not working properly in express together with nuxtjs

I am using Nuxtjs as a middleware in expressjs, and I have problems with handling errors in express server part.
When browser goes to 'localhost:3000', it will throw res.status is not a function error. when I comment that code block, everything is good expect that I cannot handle with uncaught server errors...
Any ideas?
import dotenv from 'dotenv'
dotenv.config({ silent: process.env.NODE_ENV === 'production', path: 'server/.env' })
import express from 'express'
import { ready } from 'consola'
import { Nuxt, Builder } from 'nuxt'
import cors from 'cors'
import { json, urlencoded } from 'body-parser'
import cookieParser from 'cookie-parser'
import passport from 'passport'
import './utils/auth'
import router from './routes'
const app = express()
app.use(json({ limit: '50mb' }))
app.use(urlencoded({ limit: '50mb', extended: true }))
app.use(cookieParser())
app.use(cors())
app.use(passport.initialize())
app.use('/api', router)
app.use('/api/*', (req, res) => {
res.status(404).end()
})
// error handlers
// it is problematic
// app.use((err, req, res) => {
// res.status(err.status || 500).end()
// })
let config = require('../nuxt.config.js')
config.dev = !(process.env.NODE_ENV === 'production')
async function start() {
const nuxt = new Nuxt(config)
if (config.dev) {
const builder = new Builder(nuxt)
await builder.build()
}
app.use(nuxt.render)
const host = process.env.HOST || '127.0.0.1'
const port = process.env.PORT || 3000
app.set('port', port)
app.listen(port, host)
ready({
message: `Server listening on http://${host}:${port}`,
badge: true,
})
}
start()
Without testing this code myself, I had a similar issue with my custom error handler and realized at one point I removed the next argument and it was failing. Can't say it will fix the issue because you are getting an error about res. I read through this page a few times and noticed a few mistakes I was making because I was using async functions.
Error Handling Guide may provide some help if you look over it carefully, but more specifically my comment about next is found under the title Writing error handlers
I wanted to say it might be arrow functions, but I don't see why that would break the logic here.

ExpressJS with NuxtJS middleware passing post data to page

Can someone help me understand how to pass data from post request to the nuxt page that is loaded. I dont know how to send the data to the page that will be loaded.
I want to be able to process the POST request, then send that data for usage on the following page. I am open to suggestions but I can't find proper documentation, tutorials or examples to accomplish this task.
I don't want to use axios here (with JSON type response), because I would prefer to send POST data and load new page. Therefor if page is reloaded, POST data must be submitted again.
const express = require('express')
const bodyParser = require('body-parser')
const { Nuxt, Builder } = require('nuxt')
const app = express()
const host = process.env.HOST || '127.0.0.1'
const port = process.env.PORT || 3000
// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: false }))
// parse application/json
app.use(bodyParser.json())
app.set('port', port)
// Import and Set Nuxt.js options
let config = require('../nuxt.config.js')
config.dev = !(process.env.NODE_ENV === 'production')
async function start() {
// Init Nuxt.js
const nuxt = new Nuxt(config)
// Build only in dev mode
if (config.dev) {
const builder = new Builder(nuxt)
await builder.build()
}
// Routes added
app.post('/events/booking', function (req, res, next) {
console.log('REQUEST:', req.body)
res.set('eventId', req.body.eventId)
res.set('moreData', ['some', 'more', 'data'])
next()
})
// Give nuxt middleware to express
app.use(nuxt.render)
// Listen the server
app.listen(port, host)
console.log('Server listening on http://' + host + ':' + port) // eslint-disable-line no-console
}
start()
I believe the source of your issue is the disconnect between Nuxt's implementation of Express, the deprecation/version-conflicts of bodyParser middleware and/or the Node event system.
I would personally take a step back by removing the custom express routing, handle the body parsing yourself in the middleware and take advantage of the Vuex store.
store/index.js
export const state = () => ({
postBody: null,
postError: null
})
export const mutations = {
postBody: (state, postBody) => {
state.postBody = postBody;
},
postError: (state, postError) => {
state.postError = postError;
},
}
export const getters = {
postBody: state => state.postBody,
postError: state => state.postError,
}
middleware/index.js
export default ({req, store}) => {
if (process.server && req && req.method === 'POST') {
return new Promise((resolve, reject) => {
req.on('data', data => resolve(store.commit('postBody', JSON.parse(data))));
req.on('error', data => reject(store.commit('postError', JSON.parse(data))));
})
}
}
pages/index.vue
<template>
<div>
<h1>Test page</h1>
<div v-if="postBody">
<h2>post body</h2>
<p>{{postBody}}</p>
</div>
<div v-if="postError">
<h2>post error</h2>
<p>{{postError}}</p>
</div>
<div v-if="!postError && !postBody">
Please post JSON data to this URL to see a response
</div>
</div>
</template>
<script>
import { mapGetters } from 'vuex'
export default {
middleware: 'post-data',
computed: mapGetters({
postBody: 'postBody',
postError: 'postError'
})
}
</script>
Below is a live and working example project of the above. POST JSON data using a client app (Postman, web form, etc) to see the posted data rendered on the page.
Live Code: https://glitch.com/edit/#!/terrific-velociraptor
Live Example: https://terrific-velociraptor.glitch.me/