create-react-app proxy request fails with 404 when backend is hosted on Azure

Question

I am having a bit of trouble setting up my create-react-app application to proxy requests to my test hosting on Microsoft azure. I have set up the proxy in my app's package.json as follows:

"proxy":{
   "/api/*":{
   "target":"https://mytestbackend.azurewebsites.net",
   "secure":false
}
}

I have set up an axios request to be sent to the backend server on azure. It is in a stand-alone .js which I call from one of my react application's events. It looks like this:

import axios from 'axios';

const login = async (username, password) => {
   console.log("Username to send is:"+username);
   console.log("password to send is:"+password);
   let response = await axios.post('/api/user/login',  {username:username,password:password});
   console.log(response);
};

export {login};

The problem can't be in my react components, because those two console.log() call show that the values entered are being recieved. If I remove the "secure":false setting from package.json, request fails with Http Error: 500. But if I use the secure setting, it fails with a 404 page. Can someone please shed a little light on what am I doing wrong? Can I only use the proxy on "localhost"? The documentation suggests otherwise. Any help is greatly appreciated.

I have verified that CORS is enabled for the domain on which the dev server is running on the Azure Management Portal. And if I do the request by using the backend's URL directly (that is, not using the create-react-app proxy), it works. The problem must be something in the way the proxy is configured.

The response text for the HTTP Errpr 500 which happens when not using secure is :

Proxy error: Could not proxy request /api/user/login from localhost:3000 to https://mytestbackend.azurewebsites.net (undefined).

Additional info: I have also tested by running my Backend locally on my development machine. The error message occurs but the "undefined" in the parenthesis says "UNABLE_TO_VERIFY_LEAF_SIGNATURE". If using "secure: false, I can call the login endpoint successfully, but calls to other endpoints which require authentication fail because the cookie is not sent by axios.

Doing: curl -v https://mytestbackend.azurewebsites.net/api/user/login

Has this output:

* SSLv3, TLS handshake, Client hello (1):
* SSLv3, TLS handshake, Server hello (2):
* SSLv3, TLS handshake, CERT (11):
* SSLv3, TLS alert, Server hello (2):
* SSL certificate problem: unable to get local issuer certificate
* Closing connection #0
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: http://curl.haxx.se/docs/sslcerts.html

curl performs SSL certificate verification by default, using a "bundle"
of Certificate Authority (CA) public keys (CA certs). If the default
bundle file isn't adequate, you can specify an alternate file
using the --cacert option.
If this HTTPS server uses a certificate signed by a CA represented in
the bundle, the certificate verification probably failed due to a
problem with the certificate (it might be expired, or the name might
not match the domain name in the URL).
If you'd like to turn off curl's verification of the certificate, use
the -k (or --insecure) option.

Answer 1

create-react-app use WebPackDevServer which uses https://github.com/chimurai/http-proxy-middleware#options

So you can use all the options from the same

Now one key header that is import in such cases of externally hosted server is host. This at times can issues if not correct, see below example

Websocket works on EC2 url but not on ElasticBeanstalk URL

Next is the cookies might be associated with localhost, i checked and they should go without any modification. But you might want to use the cookieDomainRewrite: "" option as well

So the final config I would use is below

"proxy":{
   "/api/*":{
   "target":"https://mytestbackend.azurewebsites.net",
   "secure":false,
      "headers": {
        "host": "mytestbackend.azurewebsites.net"
      },
      "cookieDomainRewrite": ""
  } 
}

Also on your client you want to use the withCredentials:true

let userinfo =await axios.get('/api/secured/userinfo',{withCredentials:true});

Answer 2

Create react app http-proxy-middleware, and should support the full set of options.

Some things I would try:

• The path to match may be /api/** instead of /api/* if you want to nest multiple levels deep (eg. for /api/user/login)

• You may need to add changeOrigin: true if you're proxying to something remotely (not on localhost)

• You will likely want to keep secure: false as you aren't running localhost with https.

So in total, I would try

"proxy":{
   "/api/**": {
     "target": "https://mytestbackend.azurewebsites.net",
     "secure": false,
     "changeOrigin": true
   }
}