fix: Stops auth dialog popping up on Chrome (#379)

* If a 401 http error is returned by jolokia/cluster then Chrome displays
  an authentication dialog, which is not required and disrupts the app. To
  stop the dialog appearing, the www-authentication header needs to be
  dropped from the http response.

* webpack.config.dev.js
 * In dev mode, adding the onProxyRes property to the proxy-middleware
   allows the www-authenticate header to be removed.

* nginx.js
 * In production mode, the response is already passed through the response
   function so detecting the status is 401, the www-authenticate header can
   be removed.

docker/nginx.js

@@ -35,6 +35,17 @@ function proxyJolokiaAgent(req) {
     for (var header in res.headersOut) {
       req.headersOut[header] = res.headersOut[header];
     }
+
+    if (res.status === 401) {
+      /*
+       * If an unauthorized response is received from the jolokia agent
+       * then want to avoid browsers like Chrome displaying a popup authentication
+       * dialog (initiated by the 401 status & the 'www-authenticate' header) by
+       * dropping the 'www-authenticate' header
+       */
+      delete req.headersOut['www-authenticate'];
+    }
+
     req.return(res.status, res.responseBody);
   }
 

packages/online-shell/webpack.config.dev.js

@@ -97,6 +97,17 @@ module.exports = () => {
           pathRewrite: { '^/master': '' },
           secure: false,
           ws: true,
+          onProxyRes: (proxyRes, req, res) => {
+            if (proxyRes.statusCode === 401) {
+              /*
+               * When both the 401 status code and the www-authenticate error are encountered
+               * Chrome (un)helpfully displays a pop-up login dialog. We want to disable that
+               * since it interferes with the probing of the jolokia connections
+               */
+              console.log('Unauthorized Error detected: removing www-authenticate header')
+              delete proxyRes.headers['www-authenticate']
+            }
+          },
         },
       ],