enable oslo namespace check for ceilometer project

Currently, oslo team starts to drop old oslo namespace, the old import
style can work now, but not any more in next development cycle. We've
already done and will continue do the migrate jobs, but we need a way
to prevent accidently import such issue again. The hacking rules cannot
satisfy the need, so let's do the local check.

Code are basically stolen from Nova project.

Note, this patch also fixes some new introduced oslo namespace issues.

Change-Id: I98c81c47a727ed71fb75820f21276cb989d47714

HACKING.rst

@@ -0,0 +1,11 @@
+Ceilometer Style Commandments
+=============================
+
+- Step 1: Read the OpenStack Style Commandments
+  http://docs.openstack.org/developer/hacking/
+- Step 2: Read on
+
+Ceilometer Specific Commandments
+--------------------------------
+
+- [C300] Check for oslo library imports use the non-namespaced packages

ceilometer/event/storage/impl_elasticsearch.py

@@ -16,8 +16,8 @@ import operator
 
 import elasticsearch as es
 from elasticsearch import helpers
-from oslo.utils import netutils
-from oslo.utils import timeutils
+from oslo_utils import netutils
+from oslo_utils import timeutils
 import six
 
 from ceilometer.event.storage import base

ceilometer/hacking/checks.py

@@ -0,0 +1,51 @@
+# Copyright 2015 Huawei Technologies Co., Ltd.
+#
+# 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.
+
+"""
+Guidelines for writing new hacking checks
+
+ - Use only for Ceilometer specific tests. OpenStack general tests
+   should be submitted to the common 'hacking' module.
+ - Pick numbers in the range C3xx. Find the current test with
+   the highest allocated number and then pick the next value.
+ - Keep the test method code in the source file ordered based
+   on the C3xx value.
+ - List the new rule in the top level HACKING.rst file
+ - Add test cases for each new rule to ceilometer/tests/test_hacking.py
+
+"""
+
+import re
+
+
+# TODO(zqfan): When other oslo libraries switch over non-namespace'd
+# imports, we need to add them to the regexp below.
+oslo_namespace_imports = re.compile(
+    r"(from|import) oslo[.](concurrency|config|utils|i18n|serialization)")
+
+
+def check_oslo_namespace_imports(logical_line, physical_line, filename):
+    # ignore openstack.common since they are not maintained by us
+    if 'ceilometer/openstack/common/' in filename:
+        return
+
+    if re.match(oslo_namespace_imports, logical_line):
+        msg = ("C300: '%s' must be used instead of '%s'." % (
+               logical_line.replace('oslo.', 'oslo_'),
+               logical_line))
+        yield(0, msg)
+
+
+def factory(register):
+    register(check_oslo_namespace_imports)

ceilometer/publisher/direct.py

@@ -13,8 +13,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from oslo.config import cfg
-from oslo.utils import timeutils
+from oslo_config import cfg
+from oslo_utils import timeutils
 
 from ceilometer.dispatcher import database
 from ceilometer import publisher

ceilometer/tests/compute/pollsters/test_instance.py

@@ -15,7 +15,7 @@
 # under the License.
 
 import mock
-from oslo.config import fixture as fixture_config
+from oslo_config import fixture as fixture_config
 
 from ceilometer.agent import manager
 from ceilometer.compute.pollsters import instance as pollsters_instance

ceilometer/tests/gabbi/fixtures.py

@@ -24,7 +24,7 @@ from unittest import case
 import uuid
 
 from gabbi import fixture
-from oslo.config import fixture as fixture_config
+from oslo_config import fixture as fixture_config
 
 from ceilometer.publisher import utils
 from ceilometer import sample

ceilometer/tests/publisher/test_direct.py

@@ -18,7 +18,7 @@
 import datetime
 import uuid
 
-from oslo.utils import netutils
+from oslo_utils import netutils
 
 from ceilometer.event.storage import models as event
 from ceilometer.publisher import direct

ceilometer/tests/test_hacking.py

@@ -0,0 +1,90 @@
+# Copyright 2015 Huawei Technologies Co., Ltd.
+#
+# 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 textwrap
+
+import mock
+import pep8
+from testtools import testcase
+
+from ceilometer.hacking import checks
+
+
+class HackingTestCase(testcase.TestCase):
+    """Test cases for ceilometer specific hacking rules.
+
+    This class tests the hacking checks in ceilometer.hacking.checks by
+    passing strings to the check methods like the pep8/flake8 parser would.
+    The parser loops over each line in the file and then passes the parameters
+    to the check method. The parameter names in the check method dictate what
+    type of object is passed to the check method. The parameter types are::
+
+        logical_line: A processed line with the following modifications:
+            - Multi-line statements converted to a single line.
+            - Stripped left and right.
+            - Contents of strings replaced with "xxx" of same length.
+            - Comments removed.
+        physical_line: Raw line of text from the input file.
+        lines: a list of the raw lines from the input file
+        tokens: the tokens that contribute to this logical line
+        line_number: line number in the input file
+        total_lines: number of lines in the input file
+        blank_lines: blank lines before this one
+        indent_char: indentation character in this file (" " or "\t")
+        indent_level: indentation (with tabs expanded to multiples of 8)
+        previous_indent_level: indentation on previous line
+        previous_logical: previous logical line
+        filename: Path of the file being run through pep8
+
+    When running a test on a check method the return will be False/None if
+    there is no violation in the sample input. If there is an error a tuple is
+    returned with a position in the line, and a message. So to check the result
+    just assertTrue if the check is expected to fail and assertFalse if it
+    should pass.
+    """
+
+    # We are patching pep8 so that only the check under test is actually
+    # installed.
+    @mock.patch('pep8._checks',
+                {'physical_line': {}, 'logical_line': {}, 'tree': {}})
+    def _run_check(self, code, checker, filename=None):
+        pep8.register_check(checker)
+
+        lines = textwrap.dedent(code).strip().splitlines(True)
+
+        checker = pep8.Checker(filename=filename, lines=lines)
+        checker.check_all()
+        checker.report._deferred_print.sort()
+        return checker.report._deferred_print
+
+    def _assert_has_errors(self, code, checker, expected_errors=None,
+                           filename=None):
+        actual_errors = [e[:3] for e in
+                         self._run_check(code, checker, filename)]
+        self.assertEqual(expected_errors or [], actual_errors)
+
+    def test_oslo_namespace_imports_check(self):
+        codes = [
+            "from oslo.concurrency import processutils",
+            "from oslo.config import cfg",
+            "import oslo.i18n",
+            "from oslo.utils import timeutils",
+            "from oslo.serialization import jsonutils",
+        ]
+        for code in codes:
+            self._assert_has_errors(code, checks.check_oslo_namespace_imports,
+                                    expected_errors=[(1, 0, "C300")])
+            self._assert_has_errors(
+                code, checks.check_oslo_namespace_imports,
+                filename="ceilometer/openstack/common/xyz.py")

tox.ini

@@ -98,3 +98,4 @@ show-source = True
 [hacking]
 import_exceptions =
     ceilometer.i18n
+local-check-factory = ceilometer.hacking.checks.factory