Add error message to app if secret missing in quay

util/config/provider/k8sprovider.py

@@ -50,6 +50,10 @@ class KubernetesConfigProvider(BaseFileProvider):
     # in Kubernetes secrets.
     return "_".join([directory.rstrip('/'), filename])
 
+  def volume_exists(self):
+    secret = self._lookup_secret()
+    return secret is not None
+
   def volume_file_exists(self, relative_file_path):
     if '/' in relative_file_path:
       raise Exception('Expected path from get_volume_path, but found slashes')