Switch to hacking 2.0

In hacking 2.0, local-check-factory was removed as it is not compatible
with flake8 3.x and it is advised to use flake8's local plugins [1].
Checks specific to neutron-lib registered via local-check-factory are
converted into flake8's local plugins [2].

Note that neutron_lib.hacking.checks.factory is kept not to break hacking
checks in neutron-lib consumers. They need to be converted into the style
in hacking 2.x in each repository and then we can drop the factory here.

[1] https://docs.openstack.org/releasenotes/hacking/unreleased.html#relnotes-2-0-0
[2] https://flake8.pycqa.org/en/3.7.0/user/configuration.html#using-local-plugins

Change-Id: I90419fe0b385e7bee216a52c1169aba6d6975d56

doc/source/user/hacking.rst

@@ -3,35 +3,43 @@ Hacking Checks
 ==============
 
 The ``neutron_lib.hacking`` package implements a number of public
-`hacking checks <https://github.com/openstack-dev/hacking>`_ intended to help
+`flake8 checks <https://gitlab.com/pycqa/flake8>`__ intended to help
 adopters validate their compliance with the latest hacking standards.
 
 To adopt neutron-lib's hacking checks:
 
-#. Update your project's ``tox.ini`` to use
-   ``neutron_lib.hacking.checks.factory`` for its ``local-check-factory``.
+#. Update your project's ``tox.ini`` to include hacking checks from
+   neutron-lib. More specifically, copy hacking checks under
+   "Checks for neutron and related projects" in
+   ``[flake8.local-plugin] extension`` in neutron-lib ``tox.ini``
+   to ``[flake8.local-plugin] extension`` in your project's ``tox.ini``.
 
    For example in your ``tox.ini``::
 
-       [hacking]
-       local-check-factory = neutron_lib.hacking.checks.factory
+     [flake8:local-plugins]
+     extension =
+       # Checks from neutron-lib
+       N521 = neutron_lib.hacking.checks:use_jsonutils
+       N524 = neutron_lib.hacking.checks:check_no_contextlib_nested
+       N529 = neutron_lib.hacking.checks:no_mutable_default_args
+       N530 = neutron_lib.hacking.checks:check_neutron_namespace_imports
+       N532 = neutron_lib.hacking.translation_checks:check_log_warn_deprecated
+       N534 = neutron_lib.hacking.translation_checks:check_raised_localized_exceptions
+       N536 = neutron_lib.hacking.checks:assert_equal_none
+       N537 = neutron_lib.hacking.translation_checks:no_translate_logs
 
-   If your project needs to register additional project specific hacking
-   checks, you can define your own factory function that calls neutron-lib's
-   ``factory`` function.
+   Under certain circumstances, adopters may need to ignore specific
+   neutron-lib hacking checks temporarily. You can ignore such checks
+   just by commenting out them (hopefully with a proper reason).
 
-   For example in your project's python source::
+   If your project has its own hacking checks, you can add more rules
+   to ``[flake8.local-plugin] extension`` along with hacking checks
+   from neutron-lib.
 
-       def my_factory(register):
-           # register neutron-lib checks
-           neutron_lib_checks.factory(register)
-           # register project specific checks
-           register(my_project_check)
+   .. note::
 
-   And use your project's own factory in ``tox.ini``::
-
-       [hacking]
-       local-check-factory = myproject.mypkg.my_factory
+      The above configuration assumes hacking 2.x.
+      If your project uses hacking 1.x, see :ref:`hacking1_support` below.
 
 #. Update your project's ``tox.ini`` enable any flake8 extensions neutron-lib's
    ``tox.ini`` does. These are hacking checks otherwise disabled by default
@@ -54,12 +62,40 @@ To adopt neutron-lib's hacking checks:
    hacking checks will be communicated via openstack-discuss email list
    and `neutron meetings <https://wiki.openstack.org/wiki/Network/Meetings>`_.
 
-   Under certain circumstances, adopters may need to ignore specific
-   neutron-lib hacking checks temporarily. This can be done using the
-   ``ignore`` property in the ``[flake8]`` section of your ``tox.ini``.
-   For example, to ignore the hacking check ``N536`` your tox.ini might
-   have::
+.. _hacking1_support:
 
-      [flake8]
-      # temporarily ignore N536 while fixing failing checks
-      ignore = N536
+Hacking 1.x support
+-------------------
+
+If your project uses hacking 1.x, you need a different way to consume hacking
+checks from neutron-lib.
+
+.. warning::
+
+   hacking 1.x support is deprecated and will be dropped once all neutron
+   related projects migrate to hacking 2.x.
+
+Update your project's ``tox.ini`` to use
+``neutron_lib.hacking.checks.factory`` for its ``local-check-factory``.
+
+For example in your ``tox.ini``::
+
+    [hacking]
+    local-check-factory = neutron_lib.hacking.checks.factory
+
+If your project needs to register additional project specific hacking
+checks, you can define your own factory function that calls neutron-lib's
+``factory`` function.
+
+For example in your project's python source::
+
+    def my_factory(register):
+        # register neutron-lib checks
+        neutron_lib_checks.factory(register)
+        # register project specific checks
+        register(my_project_check)
+
+And use your project's own factory in ``tox.ini``::
+
+    [hacking]
+    local-check-factory = myproject.mypkg.my_factory

neutron_lib/hacking/checks.py

@@ -14,6 +14,8 @@
 
 import re
 
+from hacking import core
+
 from neutron_lib.hacking import translation_checks
 
 # Guidelines for writing new hacking checks
@@ -41,6 +43,7 @@ assert_is_none_re = re.compile(
     r"assertIs(Not)?\(.*,\s+None\)(( |\t)*#.*)?$|assertIs(Not)?\(None,")
 
 
+@core.flake8ext
 def use_jsonutils(logical_line, filename):
     """N521 - jsonutils must be used instead of json.
 
@@ -105,6 +108,7 @@ def _check_namespace_imports(failure_code, namespace, new_ns, logical_line,
         return (0, msg_o or msg)
 
 
+@core.flake8ext
 def check_no_contextlib_nested(logical_line, filename):
     """N524 - Use of contextlib.nested is deprecated.
 
@@ -123,6 +127,7 @@ def check_no_contextlib_nested(logical_line, filename):
         yield(0, msg)
 
 
+@core.flake8ext
 def no_mutable_default_args(logical_line):
     """N529 - Method's default argument shouldn't be mutable.
 
@@ -139,6 +144,7 @@ def no_mutable_default_args(logical_line):
 # Chances are that most projects will need to put an ignore on this rule
 # until they can fully migrate to the lib.
 
+@core.flake8ext
 def check_neutron_namespace_imports(logical_line):
     """N530 - Direct neutron imports not allowed.
 
@@ -154,6 +160,7 @@ def check_neutron_namespace_imports(logical_line):
         yield x
 
 
+@core.flake8ext
 def check_no_eventlet_imports(logical_line):
     """N535 - Usage of Python eventlet module not allowed.
 
@@ -167,6 +174,7 @@ def check_no_eventlet_imports(logical_line):
         yield logical_line.index('eventlet'), msg
 
 
+@core.flake8ext
 def assert_equal_none(logical_line):
     """N536 - Use assertIsNone."""
     if assert_equal_none_re.search(logical_line):
@@ -180,6 +188,8 @@ def assert_equal_none(logical_line):
         yield logical_line.index('assert'), msg
 
 
+# TODO(amotoki): Drop this once all neutron related projects
+# have switched to hacking 2.x
 def factory(register):
     """Hacking check factory for neutron-lib adopter compliant checks.
 
@@ -197,18 +207,3 @@ def factory(register):
     register(translation_checks.check_log_warn_deprecated)
     register(translation_checks.check_raised_localized_exceptions)
     register(assert_equal_none)
-
-
-def _neutron_lib_factory(register):
-    """Hacking check factory for neutron-lib internal project checks.
-
-    Hacking check factory for use with tox.ini. This factory registers all
-    checks that are run with the neutron-lib project itself.
-
-    :param register: The function to register the check functions with.
-    :returns: None.
-    """
-    factory(register)
-
-    # neutron-lib project specific checks below
-    register(check_no_eventlet_imports)

neutron_lib/hacking/translation_checks.py

@@ -14,6 +14,8 @@
 
 import re
 
+from hacking import core
+
 
 _all_log_levels = {'critical', 'error', 'exception', 'info',
                    'warning', 'debug'}
@@ -36,6 +38,7 @@ def _translation_checks_not_enforced(filename):
     return any(pat in filename for pat in ["/tests/", "rally-jobs/plugins/"])
 
 
+@core.flake8ext
 def check_log_warn_deprecated(logical_line, filename):
     """N532 - Use LOG.warning due to compatibility with py3.
 
@@ -50,6 +53,7 @@ def check_log_warn_deprecated(logical_line, filename):
         yield (0, msg)
 
 
+@core.flake8ext
 def check_raised_localized_exceptions(logical_line, filename):
     """N534 - Untranslated exception message.
 
@@ -72,6 +76,7 @@ def check_raised_localized_exceptions(logical_line, filename):
             yield (logical_line.index(exception_msg), msg)
 
 
+@core.flake8ext
 def no_translate_logs(logical_line, filename):
     """N537 - Don't translate logs.
 

neutron_lib/placement/client.py

@@ -117,7 +117,7 @@ class NoAuthClient(object):
                 LOG.exception('requests Timeout, let\'s retry it...')
             except requests.ConnectionError:
                 LOG.exception('Connection Error appeared')
-            except requests.RequestException as e:
+            except requests.RequestException:
                 LOG.exception('Some really weird thing happened, let\'s '
                               'retry it')
             time.sleep(self.timeout)

neutron_lib/tests/unit/hacking/test_checks.py

@@ -40,17 +40,6 @@ class HackingTestCase(base.BaseTestCase):
     def test_factory(self):
         self.assertGreater(len(self._get_factory_checks(checks.factory)), 0)
 
-    def test_neutron_lib_factory(self):
-        lib_checks = self._get_factory_checks(checks._neutron_lib_factory)
-        other_checks = self._get_factory_checks(checks.factory)
-
-        self.assertGreater(len(lib_checks), 0)
-
-        if other_checks:
-            for other_check in other_checks:
-                # lib checks are superset of all checks
-                self.assertTrue(other_check in lib_checks)
-
     def test_use_jsonutils(self):
         def __get_msg(fun):
             msg = ("N521: jsonutils.%(fun)s must be used instead of "

test-requirements.txt

@@ -2,7 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking>=1.1.0,<1.2.0 # Apache-2.0
+hacking>=2.0.0,<2.1 # Apache-2.0
 
 bandit!=1.6.0,>=1.1.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0

tox.ini

@@ -101,6 +101,20 @@ show-source = True
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build,tools
 import-order-style = pep8
 
+[flake8:local-plugins]
+extension =
+  # Checks for neutron and related projects
+  N521 = neutron_lib.hacking.checks:use_jsonutils
+  N524 = neutron_lib.hacking.checks:check_no_contextlib_nested
+  N529 = neutron_lib.hacking.checks:no_mutable_default_args
+  N530 = neutron_lib.hacking.checks:check_neutron_namespace_imports
+  N532 = neutron_lib.hacking.translation_checks:check_log_warn_deprecated
+  N534 = neutron_lib.hacking.translation_checks:check_raised_localized_exceptions
+  N536 = neutron_lib.hacking.checks:assert_equal_none
+  N537 = neutron_lib.hacking.translation_checks:no_translate_logs
+  # Checks specific to neutron-lib only
+  N535 = neutron_lib.hacking.checks:check_no_eventlet_imports
+
 [testenv:bandit]
 # B104: Possible binding to all interfaces
 # B303: Blacklist use of insecure MD2, MD4, MD5, or SHA1 hash functions
@@ -110,7 +124,6 @@ commands = bandit -r neutron_lib -x tests -n5 -s B104,B303,B311
 
 [hacking]
 import_exceptions = neutron_lib._i18n
-local-check-factory = neutron_lib.hacking.checks._neutron_lib_factory
 
 [testenv:lower-constraints]
 deps =