Auth0 Webtask App

Prototype that demonstrates authentication to a static web page. The main page is rendered using React, but the data is behind an authentication layer. Authentication is done via the Auth0 Lock app which verifies the login details with it's own database and sends back an auth token. This is then used in a Webtask serverless function to make the API call to JSON Placeholder and then sends back the data to be rendered.

Below is the code used in the Webtask function:

const app = new (require('express'))();
const wt = require('webtask-tools');
const request = require('request');
const bodyParser = require('body-parser');

//we'll use jsonplaceholder to get our fake data
const apiBaseUrl = 'https://jsonplaceholder.typicode.com';

//our custom api error responses
const RESPONSE = {
  ERROR: {
    statusCode: 400,
    message: 'Error from Webtask: Something went wrong. Please try again later.'
  },
  UNAUTHORIZED: {
    status: 401,
    message: 'Error from Webtask: You\'re not currently authorized to view this content. Please login.'
  }
};

//https://stackoverflow.com/questions/38306569/what-does-body-parser-do-with-express
//parse the body of the request otherwise it won't work
app.use(bodyParser.json());

app.get('/users', (req, res) => {
    const requestUrl = `${apiBaseUrl}/users`;

    //request the data from jsonplaceholder user endpoint and send it back to the client
    request(requestUrl, (error, response, body) => {
      if(error){
        res.writeHead(400, { 'Content-Type': 'application/json'});
        res.end(JSON.stringify(RESPONSE.ERROR));
      } else {
        res.writeHead(200, { 'Content-Type': 'application/json'});
        res.end(body);
      }
    });

});

//here we are exporting our express app using the wt helper
//library and using auth0 to secure the apps endpoints
module.exports = wt.fromExpress(app).auth0({
  //implementing a custom login error function which will send
  //the user an appropriate message if the request is not authorized
  loginError: (error, ctx, req, res) => {
        res.writeHead(401, { 'Content-Type': 'application/json'});
        res.end(JSON.stringify(RESPONSE.UNAUTHORIZED));
  }
});

Build Steps

npm install npm start