add Rancher SAML processor

passbook/lib/default.yml

@@ -101,3 +101,4 @@ saml_idp:
     - passbook.saml_idp.processors.salesforce
     - passbook.saml_idp.processors.shibboleth
     - passbook.saml_idp.processors.wordpress_orange
+    - passbook.saml_idp.processors.rancher

passbook/saml_idp/processors/rancher.py

@@ -0,0 +1,11 @@
+"""Rancher Processor"""
+from passbook.saml_idp.base import Processor
+
+
+class RancherProcessor(Processor):
+    """Rancher SAML 2.0 AuthnRequest to Response Handler Processor."""
+
+    def _determine_audience(self):
+        # Rancher expects an audience in this format
+        # https://<host>/v1-saml/adfs/saml/acs
+        self._audience = self._remote.acs_url.replace('acs', 'metadata')