From 0832a0355381229ece235440a9c5de1301e51d07 Mon Sep 17 00:00:00 2001
From: Dave McCowan <dmccowan@cisco.com>
Date: Mon, 7 Dec 2015 14:25:24 -0500
Subject: [PATCH] Check context before returning cached value

The key manager caches the value of barbican client to be reused,
saving an extra call to keystone.  The cached value is only
applicable to the current context, so the context must be checked
before returning the cached value.

Change-Id: Ib10909a098fb2cd070129c239b6d3b95edc8fea0
Closes-Bug: #1523646
---
 cinder/keymgr/barbican.py                 | 53 +++++++++++++----------
 cinder/tests/unit/keymgr/test_barbican.py |  1 +
 2 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/cinder/keymgr/barbican.py b/cinder/keymgr/barbican.py
index 10373c2af..9f71890b5 100644
--- a/cinder/keymgr/barbican.py
+++ b/cinder/keymgr/barbican.py
@@ -49,6 +49,7 @@ class BarbicanKeyManager(key_mgr.KeyManager):
         self._base_url = CONF.keymgr.encryption_api_url
         self._parse_barbican_api_url()
         self._barbican_client = None
+        self._current_context = None
 
     def _parse_barbican_api_url(self):
         """Setup member variables to reference the Barbican URL.
@@ -84,30 +85,34 @@ class BarbicanKeyManager(key_mgr.KeyManager):
                                  or project_id is None
         """
 
-        if not self._barbican_client:
-            # Confirm context is provided, if not raise not authorized
-            if not ctxt:
-                msg = _("User is not authorized to use key manager.")
-                LOG.error(msg)
-                raise exception.NotAuthorized(msg)
-
-            if not hasattr(ctxt, 'project_id') or ctxt.project_id is None:
-                msg = _("Unable to create Barbican Client without project_id.")
-                LOG.error(msg)
-                raise exception.KeyManagerError(msg)
-
-            try:
-                auth = identity.v3.Token(
-                    auth_url=CONF.keymgr.encryption_auth_url,
-                    token=ctxt.auth_token,
-                    project_id=ctxt.project_id)
-                sess = session.Session(auth=auth)
-                self._barbican_client = barbican_client.Client(
-                    session=sess,
-                    endpoint=self._barbican_endpoint)
-            except Exception:
-                with excutils.save_and_reraise_exception():
-                    LOG.exception(_LE("Error creating Barbican client."))
+        # Confirm context is provided, if not raise not authorized
+        if not ctxt:
+            msg = _("User is not authorized to use key manager.")
+            LOG.error(msg)
+            raise exception.NotAuthorized(msg)
+
+        if not hasattr(ctxt, 'project_id') or ctxt.project_id is None:
+            msg = _("Unable to create Barbican Client without project_id.")
+            LOG.error(msg)
+            raise exception.KeyManagerError(msg)
+
+        # If same context, return cached barbican client
+        if self._barbican_client and self._current_context == ctxt:
+            return self._barbican_client
+
+        try:
+            auth = identity.v3.Token(
+                auth_url=CONF.keymgr.encryption_auth_url,
+                token=ctxt.auth_token,
+                project_id=ctxt.project_id)
+            sess = session.Session(auth=auth)
+            self._barbican_client = barbican_client.Client(
+                session=sess,
+                endpoint=self._barbican_endpoint)
+            self._current_context = ctxt
+        except Exception:
+            with excutils.save_and_reraise_exception():
+                LOG.exception(_LE("Error creating Barbican client."))
 
         return self._barbican_client
 
diff --git a/cinder/tests/unit/keymgr/test_barbican.py b/cinder/tests/unit/keymgr/test_barbican.py
index 694bee619..77e4ed903 100644
--- a/cinder/tests/unit/keymgr/test_barbican.py
+++ b/cinder/tests/unit/keymgr/test_barbican.py
@@ -78,6 +78,7 @@ class BarbicanKeyManagerTestCase(test_key_mgr.KeyManagerTestCase):
         self.create = self.mock_barbican.secrets.create
 
         self.key_mgr._barbican_client = self.mock_barbican
+        self.key_mgr._current_context = self.ctxt
 
     def _build_mock_symKey(self):
         self.mock_symKey = mock.Mock()
-- 
2.45.2