Adding in cancel notifications

static/js/services/external-notification-data.js

@@ -80,6 +80,22 @@ function(Config, Features, VulnerabilityService) {
             'placeholder': '(refs/heads/somebranch)|(refs/tags/sometag)'
           }
         ]
+      },
+      {
+        'id': 'build_cancelled',
+        'title': 'Docker Build Cancelled',
+        'icon': 'fa-minus-circle',
+        'fields': [
+          {
+            'name': 'ref-regex',
+            'type': 'regex',
+            'title': 'matching ref(s)',
+            'help_text': 'An optional regular expression for matching the git branch or tag ' +
+                         'git ref. If left blank, the notification will fire for all builds.',
+            'optional': true,
+            'placeholder': '(refs/heads/somebranch)|(refs/tags/sometag)'
+          }
+        ]
       }];
 
     for (var i = 0; i < buildEvents.length; ++i) {