added deprecated.warn helper method

provide a convenience method for indicating in code that a config
option the operateor will have to deal with exists in their environment.

Change-Id: I17b0c120d54b1db75c6bb29d107e4a15a5202e76

4 files changed, 89 insertions, 1 deletions

diff --git a/nova/common/deprecated.py b/nova/common/deprecated.py
new file mode 100644
index 000000000..a442c1506
--- /dev/null
+++ b/nova/common/deprecated.py
@@ -0,0 +1,42 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright (c) 2012 IBM
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from nova import exception
+from nova import flags
+from nova import log as logging
+from nova.openstack.common import cfg
+
+LOG = logging.getLogger(__name__)
+
+deprecate_opts = [
+    cfg.BoolOpt('fatal_deprecations',
+                default=False,
+                help='make deprecations fatal')
+    ]
+FLAGS = flags.FLAGS
+FLAGS.register_opts(deprecate_opts)
+
+
+def warn(msg=""):
+    """
+    Warn of a deprecated config option that an operator has specified.
+    This should be added in the code where we've made a change in how
+    we use some operator changeable parameter to indicate that it will
+    go away in a future version of OpenStack.
+    """
+    LOG.warn(_("Deprecated Config: %s") % msg)
+    if FLAGS.fatal_deprecations:
+        raise exception.DeprecatedConfig(msg=msg)
diff --git a/nova/exception.py b/nova/exception.py
index 2c43d36f4..df21f0273 100644
--- a/nova/exception.py
+++ b/nova/exception.py
@@ -175,6 +175,10 @@ class DBError(NovaException):
         super(DBError, self).__init__(str(inner_exception))
 
 
+class DeprecatedConfig(NovaException):
+    message = _("Fatal call to deprecated config %(msg)")
+
+
 class DecryptionFailure(NovaException):
     message = _("Failed to decrypt text")
 
diff --git a/nova/tests/test_deprecated.py b/nova/tests/test_deprecated.py
new file mode 100644
index 000000000..e65baa53e
--- /dev/null
+++ b/nova/tests/test_deprecated.py
@@ -0,0 +1,40 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+#
+#    Copyright 2010 OpenStack LLC
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from nova.common import deprecated
+from nova import exception
+from nova import test
+
+
+class DeprecatedConfigTestCase(test.TestCase):
+    def setUp(self):
+        super(DeprecatedConfigTestCase, self).setUp()
+        self.logbuffer = ""
+
+        def local_log(msg):
+            self.logbuffer = msg
+
+        self.stubs.Set(deprecated.LOG, 'warn', local_log)
+
+    def test_deprecated(self):
+        deprecated.warn('test')
+        self.assertEqual(self.logbuffer, 'Deprecated Config: test')
+
+    def test_deprecated_fatal(self):
+        self.flags(fatal_deprecations=True)
+        self.assertRaises(exception.DeprecatedConfig,
+                          deprecated.warn, "test2")
+        self.assertEqual(self.logbuffer, 'Deprecated Config: test2')
diff --git a/nova/virt/connection.py b/nova/virt/connection.py
index c792ff966..0c7c3bd0a 100644
--- a/nova/virt/connection.py
+++ b/nova/virt/connection.py
@@ -21,6 +21,7 @@
 
 import sys
 
+from nova.common import deprecated
 from nova import exception
 from nova import flags
 from nova import log as logging
@@ -66,7 +67,8 @@ def get_connection(read_only=False):
                             * baremetal
 
     """
-    LOG.warning(_('Specifying virt driver via connection_type is deprecated'))
+    deprecated.warn(_('Specifying virt driver via connection_type is '
+                      'deprecated. Use compute_driver=classname instead.'))
 
     driver_name = known_drivers.get(FLAGS.connection_type)