No "Access-Control-Allow-Origin" react to express docker app

I am using docker to run a front end handling application and node / express api. The reactive app runs on localhost:3000

, and the api runs on localhost:9000

. They are fully functional and functional applications. However, when I try to make a rest call from the React app before http://localhost:9000/api/whatever

, I get the following error:

XMLHttpRequest cannot load http://localhost:9000/api/schedule. No
Access-Control-Allow-Origin' header is present on the requested 
resource. Origin 'http://localhost:3000' is therefore not allowed access.`

      

This is my server.js file for my express api:

const express = require('express');
const port = process.env.PORT || 9000;

const app = express();

require('./app/routes')(app);
app.use(function(req, res, next) {
    // Website you wish to allow to connect
    res.setHeader('Access-Control-Allow-Origin', 'http://localhost:3000');

    // Request methods you wish to allow
    res.setHeader('Access-Control-Allow-Methods', 'GET');

    // Request headers you wish to allow
    res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');

    // Set to true if you need the website to include cookies in the requests sent
    // to the API (e.g. in case you use sessions)
    res.setHeader('Access-Control-Allow-Credentials', true);

    // Pass to next layer of middleware
    next();
});
app.listen(port, () => {
    console.log('listening on port : ' + port);
})

      

Not sure what I'm missing here.

chrome network tab:

Request URL:http://localhost:9000/api/schedule
Request Method:GET
Status Code:200 OK
Remote Address:[::1]:9000
Response Headers
view source
Connection:keep-alive
Content-Length:86
Content-Type:application/json; charset=utf-8
Date:Mon, 10 Apr 2017 04:40:06 GMT
ETag:W/"56-l2wi6AdD2GGTOMvRjRYO96YmR0w"
X-Powered-By:Express
Request Headers
view source
Accept:application/json, text/plain, */*
Accept-Encoding:gzip, deflate, sdch, br
Accept-Language:en-US,en;q=0.8
Connection:keep-alive
Host:localhost:9000
Origin:http://localhost:3000
Referer:http://localhost:3000/
User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36

      

+3


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2 answers


I could have done this before with the following configuration:

app.use((req, res, next) => {
  const origin = req.get('origin');

  // TODO Add origin validation
  res.header('Access-Control-Allow-Origin', origin);
  res.header('Access-Control-Allow-Credentials', true);
  res.header('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept, Authorization, Cache-Control, Pragma');

  // intercept OPTIONS method
  if (req.method === 'OPTIONS') {
    res.sendStatus(204);
  } else {
    next();
  }
});

      



As you can see in my case, I have provided more methods than just GET

and added additional allowed headers (for example Authorization

, which I need in this case), please note that in your case, you only specified X-Requested-With

and Content-Type

, but you may need Origin

, if you want to check the origin.

I also intercept the request OPTIONS

to avoid sending additional data in this case.

+2


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I would recommend trying to install the dependency cors

,

https://github.com/expressjs/cors



If you need a link to handle this, you can check out your repo.

https://github.com/SgSridhar/bookmarks-api

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