ConfigProviders abstract over path construction

Fixes issue where certs can't be uploaded in UI in k8s

util/config/provider/k8sprovider.py

@@ -54,6 +54,19 @@ class KubernetesConfigProvider(FileConfigProvider):
       self._update_secret_file(filename, contents)
     except IOError as ioe:
       raise CannotWriteConfigException(str(ioe))
+    
+  def volume_file_exists(self, filename):
+    secret = self._lookup_secret()
+    return filename in secret
+    
+
+  def list_volume_directory(self, path):
+    secret = self._lookup_secret()
+    
+    paths = []
+    for filename in secret:
+      if filename.startswith(path):
+        paths.append(filename[len(path) + 1:])
 
   def remove_volume_file(self, filename):
     super(KubernetesConfigProvider, self).remove_volume_file(filename)
@@ -130,3 +143,6 @@ class KubernetesConfigProvider(FileConfigProvider):
 
     request = Request(method, url, data=data, headers=headers)
     return session.send(request.prepare(), verify=False, timeout=2)
+
+  def get_volume_path(self, directory, file):
+    return "_".join([directory, file])