Sync 'versionutils' module from oslo-incubator

The versionutils module hasn't had a sync since November of 2014.
There have been namespace changes and changes to enable moving to
the new oslo_log library.  So, we need this sync so that we can
move forward with those changes.

Current HEAD in OSLO:
---------------------
commit e589dde0721a0a67e4030813e582afec6e70d042
Date:  Wed Feb 18 03:08:12 2015 +0000
Merge "Have a little fun with release notes"

Changes merged with this patch:
---------------------
9bf01f9d - Switch from oslo.config to oslo_config
2fbf5065 - Remove oslo.log code and clean up versionutils API

Change-Id: I4344ed8fb234135a199649c5ef7620e4166fbb12

diff --git a/cinder/openstack/common/versionutils.py b/cinder/openstack/common/versionutils.py
index 39f3996ddc2402dbaf19f29f3f0ac9869e637baf..b80b69d685b2c145bd2a0df7152bb08738d73afe 100644 (file)
--- a/cinder/openstack/common/versionutils.py
+++ b/cinder/openstack/common/versionutils.py
@@ -19,15 +19,24 @@ Helpers for comparing version strings.
 
 import functools
 import inspect
+import logging
 
+from oslo.config import cfg
 import pkg_resources
 import six
 
 from cinder.openstack.common._i18n import _
-from cinder.openstack.common import log as logging
 
 
 LOG = logging.getLogger(__name__)
+CONF = cfg.CONF
+
+
+opts = [
+    cfg.BoolOpt('fatal_deprecations',
+                default=False,
+                help='Enables or disables fatal status of deprecations.'),
+]
 
 
 class deprecated(object):
@@ -127,7 +136,7 @@ class deprecated(object):
 
             @six.wraps(func_or_cls)
             def wrapped(*args, **kwargs):
-                LOG.deprecated(msg, details)
+                report_deprecated_feature(LOG, msg, details)
                 return func_or_cls(*args, **kwargs)
             return wrapped
         elif inspect.isclass(func_or_cls):
@@ -136,10 +145,10 @@ class deprecated(object):
             # TODO(tsufiev): change `functools` module to `six` as
             # soon as six 1.7.4 (with fix for passing `assigned`
             # argument to underlying `functools.wraps`) is released
-            # and added to the cinder-incubator requrements
+            # and added to the oslo-incubator requrements
             @functools.wraps(orig_init, assigned=('__name__', '__doc__'))
             def new_init(self, *args, **kwargs):
-                LOG.deprecated(msg, details)
+                report_deprecated_feature(LOG, msg, details)
                 orig_init(self, *args, **kwargs)
             func_or_cls.__init__ = new_init
             return func_or_cls
@@ -201,3 +210,44 @@ def is_compatible(requested_version, current_version, same_major=True):
         return False
 
     return current_parts >= requested_parts
+
+
+# Track the messages we have sent already. See
+# report_deprecated_feature().
+_deprecated_messages_sent = {}
+
+
+def report_deprecated_feature(logger, msg, *args, **kwargs):
+    """Call this function when a deprecated feature is used.
+
+    If the system is configured for fatal deprecations then the message
+    is logged at the 'critical' level and :class:`DeprecatedConfig` will
+    be raised.
+
+    Otherwise, the message will be logged (once) at the 'warn' level.
+
+    :raises: :class:`DeprecatedConfig` if the system is configured for
+             fatal deprecations.
+    """
+    stdmsg = _("Deprecated: %s") % msg
+    CONF.register_opts(opts)
+    if CONF.fatal_deprecations:
+        logger.critical(stdmsg, *args, **kwargs)
+        raise DeprecatedConfig(msg=stdmsg)
+
+    # Using a list because a tuple with dict can't be stored in a set.
+    sent_args = _deprecated_messages_sent.setdefault(msg, list())
+
+    if args in sent_args:
+        # Already logged this message, so don't log it again.
+        return
+
+    sent_args.append(args)
+    logger.warn(stdmsg, *args, **kwargs)
+
+
+class DeprecatedConfig(Exception):
+    message = _("Fatal call to deprecated config: %(msg)s")
+
+    def __init__(self, msg):
+        super(Exception, self).__init__(self.message % dict(msg=msg))