YARN-8797. [UI2] Improve error pages in new YARN UI. Contributed by Akhil PB.

(cherry picked from commit 94d82f416258b65c8ab7849a459af78abebdf7d0)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-ui/src/main/webapp/app/controllers/application.js

@@ -61,11 +61,14 @@ export default Ember.Controller.extend({
   }.property('currentPath'),
 
   clusterInfo: function() {
-    return this.model.clusterInfo.get('firstObject');
+    if (this.model && this.model.clusterInfo) {
+      return this.model.clusterInfo.get('firstObject');
+    }
+    return null;
   }.property('model.clusterInfo'),
 
   userInfo: function() {
-    if (this.model.userInfo) {
+    if (this.model && this.model.userInfo) {
       return this.model.userInfo.get('firstObject');
     }
     return null;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-ui/src/main/webapp/app/router.js

@@ -70,9 +70,6 @@ Router.map(function() {
     this.route('info', {path: '/:component_name/instances/:instance_name/info'});
   });
   this.route('yarn-app-attempt', { path: '/yarn-app-attempt/:app_attempt_id'});
-  this.route('error');
-  this.route('notfound', { path: '*:' });
-  this.route('notauth', { path: '*:' });
   this.route('yarn-queues', { path: '/yarn-queues/:queue_name' });
   this.route('yarn-queue-apps', { path: '/yarn-queue-apps/:queue_name' });
   this.route('yarn-tools', function() {
@@ -92,6 +89,10 @@ Router.map(function() {
   });
   this.route('yarn-flowrun-metric', { path: '/yarn-flowrun-metric/:flowrun_uid/:metric_id'});
   this.route('timeline-error', {path: 'timeline-error/:error_id'});
+
+  this.route('notauth');
+  this.route('notfound');
+  this.route('error', { path: '*:' });
 });
 
 export default Router;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-ui/src/main/webapp/app/routes/application.js

@@ -22,7 +22,9 @@ import AbstractRoute from './abstract';
 export default AbstractRoute.extend({
   model() {
     return Ember.RSVP.hash({
-      clusterInfo: this.store.findAll('ClusterInfo', {reload: true}),
+      clusterInfo: this.store.findAll('ClusterInfo', {reload: true}).catch(function() {
+        return null;
+      }),
       userInfo: this.store.findAll('cluster-user-info', {reload: true}).catch(function() {
         return null;
       })
@@ -37,7 +39,9 @@ export default AbstractRoute.extend({
      * error handler page.
      */
     error: function (error) {
-      Ember.Logger.log(error.stack);
+      if (error && error.stack) {
+        Ember.Logger.log(error.stack);
+      }
 
       if (error && error.errors[0] && parseInt(error.errors[0].status) === 404) {
         this.intermediateTransitionTo('/notfound');

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-ui/src/main/webapp/app/templates/error.hbs

@@ -16,4 +16,4 @@
   limitations under the License.
 --}}
 
-<h3 align = "center">Sorry, Error Occurred.</h3>
+<h3 align = "center">Sorry, error occurred.</h3>

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-ui/src/main/webapp/app/templates/notfound.hbs

@@ -17,4 +17,4 @@
 --}}
 
 <h2 align = "center">404, Not Found</h2>
-<h4 align = "center">Please Check your URL</h4>
+<h4 align = "center">Please check your URL</h4>