Drop use of 'oslo' namespace package

The Oslo libraries have moved all of their code out of the 'oslo'
namespace package into per-library packages. The namespace package was
retained during kilo for backwards compatibility, but will be removed by
the liberty-2 milestone. This change removes the use of the namespace
package, replacing it with the new package names, and adds a hacking
check to prevent regressions.

The patches in the libraries will be put on hold until application
patches have landed, or L2, whichever comes first. At that point, new
versions of the libraries without namespace packages will be released as
a major version update.

Please merge this patch, or an equivalent, before L2 to avoid problems
with those library releases.

Blueprint: remove-namespace-packages
https://blueprints.launchpad.net/oslo-incubator/+spec/remove-namespace-packages

Change-Id: I7137e7199f1cd6cdeacbc6c421d294f596e2ec0e

mistral/hacking/checks.py

@@ -0,0 +1,42 @@
+# Copyright (c) 2014 OpenStack Foundation.
+#
+# 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.
+
+import re
+
+
+oslo_namespace_imports_dot = re.compile(r"import[\s]+oslo[.][^\s]+")
+oslo_namespace_imports_from_dot = re.compile(r"from[\s]+oslo[.]")
+oslo_namespace_imports_from_root = re.compile(r"from[\s]+oslo[\s]+import[\s]+")
+
+
+def check_oslo_namespace_imports(logical_line):
+    if re.match(oslo_namespace_imports_from_dot, logical_line):
+        msg = ("O323: '%s' must be used instead of '%s'.") % (
+            logical_line.replace('oslo.', 'oslo_'),
+            logical_line)
+        yield(0, msg)
+    elif re.match(oslo_namespace_imports_from_root, logical_line):
+        msg = ("O323: '%s' must be used instead of '%s'.") % (
+            logical_line.replace('from oslo import ', 'import oslo_'),
+            logical_line)
+        yield(0, msg)
+    elif re.match(oslo_namespace_imports_dot, logical_line):
+        msg = ("O323: '%s' must be used instead of '%s'.") % (
+            logical_line.replace('import', 'from').replace('.', ' import '),
+            logical_line)
+        yield(0, msg)
+
+
+def factory(register):
+    register(check_oslo_namespace_imports)

mistral/tests/config.py

@@ -14,7 +14,7 @@
 
 import os
 
-from oslo.config import cfg
+from oslo_config import cfg
 
 
 def parse_args():

mistral/tests/unit/db/v2/test_sqlite_transactions.py

@@ -16,7 +16,7 @@
 
 import eventlet
 from eventlet import semaphore
-from oslo.config import cfg
+from oslo_config import cfg
 import testtools
 
 from mistral.db.v2.sqlalchemy import api as db_api

tox.ini

@@ -49,3 +49,6 @@ show-source = true
 ignore = H803,H305,H405
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,tools,scripts
+
+[hacking]
+local-check-factory = mistral.hacking.checks.factory