Add in openstack common and remove patch references.

Take some basic module from openstack oslo incubator and
use them to replace functionality that was in nova when
this patch was formed. Remove other references to make this
more of a general library from the get-go.

openstack-common.conf

@@ -0,0 +1,9 @@
+[DEFAULT]
+
+# The list of modules to copy from oslo-incubator.git
+module=excutils
+module=log
+
+# The base module to hold the copy of openstack.common
+base=taskflow
+

taskflow/openstack/common/excutils.py

@@ -0,0 +1,51 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 OpenStack Foundation.
+# Copyright 2012, Red Hat, Inc.
+#
+#    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.
+
+"""
+Exception related utilities.
+"""
+
+import contextlib
+import logging
+import sys
+import traceback
+
+from taskflow.openstack.common.gettextutils import _
+
+
+@contextlib.contextmanager
+def save_and_reraise_exception():
+    """Save current exception, run some code and then re-raise.
+
+    In some cases the exception context can be cleared, resulting in None
+    being attempted to be re-raised after an exception handler is run. This
+    can happen when eventlet switches greenthreads or when running an
+    exception handler, code raises and catches an exception. In both
+    cases the exception context will be cleared.
+
+    To work around this, we save the exception state, run handler code, and
+    then re-raise the original exception. If another exception occurs, the
+    saved exception is logged and the new exception is re-raised.
+    """
+    type_, value, tb = sys.exc_info()
+    try:
+        yield
+    except Exception:
+        logging.error(_('Original exception being dropped: %s'),
+                      traceback.format_exception(type_, value, tb))
+        raise
+    raise type_, value, tb

taskflow/openstack/common/gettextutils.py

@@ -0,0 +1,50 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2012 Red Hat, Inc.
+# All Rights Reserved.
+#
+#    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.
+
+"""
+gettext for openstack-common modules.
+
+Usual usage in an openstack.common module:
+
+    from taskflow.openstack.common.gettextutils import _
+"""
+
+import gettext
+import os
+
+_localedir = os.environ.get('taskflow'.upper() + '_LOCALEDIR')
+_t = gettext.translation('taskflow', localedir=_localedir, fallback=True)
+
+
+def _(msg):
+    return _t.ugettext(msg)
+
+
+def install(domain):
+    """Install a _() function using the given translation domain.
+
+    Given a translation domain, install a _() function using gettext's
+    install() function.
+
+    The main difference from gettext.install() is that we allow
+    overriding the default localedir (e.g. /usr/share/locale) using
+    a translation-domain-specific environment variable (e.g.
+    NOVA_LOCALEDIR).
+    """
+    gettext.install(domain,
+                    localedir=os.environ.get(domain.upper() + '_LOCALEDIR'),
+                    unicode=True)