adding neutron to sessions module

this change adds neutron to the sessions module and updates the neutron
client to use sessions and auth plugins. it also adjust the ssh_remote
module to not pass the endpoint url as this will be determined by the
session.

* adding neutron to sessions module
* updating neutron client to use sessions and auth plugin
* removing endpoint url discovery for neutron from ssh_remote
* adding neutron to session tests
* fixing neutron client tests
* fixing ssh_remote tests
* renaming token_auth function in keystone to make it more public

Change-Id: Icaa71a06d36c6828366f8d322ec3bed3e238506b
Partial-Implements: blueprint keystone-sessions

sahara/service/sessions.py

@@ -30,6 +30,7 @@ _SESSION_CACHE = None
 SESSION_TYPE_CINDER = 'cinder'
 SESSION_TYPE_GENERIC = 'generic'
 SESSION_TYPE_KEYSTONE = 'keystone'
+SESSION_TYPE_NEUTRON = 'neutron'
 SESSION_TYPE_NOVA = 'nova'
 
 
@@ -59,6 +60,7 @@ class SessionCache(object):
             SESSION_TYPE_CINDER: self.get_cinder_session,
             SESSION_TYPE_GENERIC: self.get_generic_session,
             SESSION_TYPE_KEYSTONE: self.get_keystone_session,
+            SESSION_TYPE_NEUTRON: self.get_neutron_session,
             SESSION_TYPE_NOVA: self.get_nova_session,
         }
 
@@ -120,6 +122,17 @@ class SessionCache(object):
             self._set_session(SESSION_TYPE_KEYSTONE, session)
         return session
 
+    def get_neutron_session(self):
+        session = self._sessions.get(SESSION_TYPE_NEUTRON)
+        if not session:
+            if CONF.neutron.ca_file:
+                session = keystone.Session(cert=CONF.neutron.ca_file,
+                                           verify=CONF.neutron.api_insecure)
+            else:
+                session = self.get_generic_session()
+            self._set_session(SESSION_TYPE_NEUTRON, session)
+        return session
+
     def get_nova_session(self):
         session = self._sessions.get(SESSION_TYPE_NOVA)
         if not session: