Add response handlers to support different response types

Problem description
===================
The dynamic pollsters only support APIs that produce
JSON responses. Therefore the dynamic pollsters do not
support APIs where the response is an XML or not Restful
compliant APIs with HTTP 200 within a plain text message
on errors.

Proposal
========
To allow the dynamic pollsters to support other APIs
response formats, we propose to add a response handling
that supports multiple response types. It must be
configurable in the dynamic pollsters YAML. The default
continues to be JSON.

Change-Id: I4886cefe06eccac2dc24adbc2fad2166bcbfdd2c

1 files changed, 4 insertions, 0 deletions

diff --git a/ceilometer/declarative.py b/ceilometer/declarative.py
index ed59f9a9..d30fff52 100644
--- a/ceilometer/declarative.py
+++ b/ceilometer/declarative.py
@@ -49,6 +49,10 @@ class DynamicPollsterDefinitionException(DynamicPollsterException):
     pass
 
 
+class InvalidResponseTypeException(DynamicPollsterException):
+    pass
+
+
 class NonOpenStackApisDynamicPollsterException\
         (DynamicPollsterDefinitionException):
     pass