Use LOG.warning instead of deprecated LOG.warn

The LOG.warn method is deprecated[1] and the LOG.warning method should
be used instead.

[1] https://docs.python.org/3/library/logging.html#logging.warning

Change-Id: I43e2269d4b1c425119c86919eb869941d621c6de

HACKING.rst

@@ -26,6 +26,7 @@ Tempest Specific Commandments
 - [T116] Unsupported 'message' Exception attribute in PY3
 - [T117] Check negative tests have ``@decorators.attr(type=['negative'])``
   applied.
+- [T118] LOG.warn is deprecated. Enforce use of LOG.warning.
 
 It is recommended to use ``tox -eautopep8`` before submitting a patch.
 

tempest/cmd/verify_tempest_config.py

@@ -130,7 +130,7 @@ def verify_glance_api_versions(os, update):
             msg = ('Glance is available in the catalog, but no known version, '
                    '(v1.x or v2.x) of Glance could be found, so Glance should '
                    'be configured as not available')
-            LOG.warn(msg)
+            LOG.warning(msg)
             print_and_or_update('glance', 'service-available', False, update)
             return
 

tempest/hacking/checks.py

@@ -318,3 +318,16 @@ def negative_test_attribute_always_applied_to_negative_tests(physical_line,
                        " to all negative API tests"
                 )
             _HAVE_NEGATIVE_DECORATOR = False
+
+
+@core.flake8ext
+def no_log_warn(logical_line):
+    """Disallow 'LOG.warn('
+
+    Use LOG.warning() instead of Deprecated LOG.warn().
+    https://docs.python.org/3/library/logging.html#logging.warning
+    """
+
+    msg = ("T118: LOG.warn is deprecated, please use LOG.warning!")
+    if "LOG.warn(" in logical_line:
+        yield (0, msg)

tempest/tests/test_hacking.py

@@ -240,3 +240,9 @@ class HackingTestCase(base.TestCase):
             with_other_decorators=True,
             with_negative_decorator=False,
             expected_success=False)
+
+    def test_no_log_warn(self):
+        self.assertFalse(list(checks.no_log_warn(
+            'LOG.warning("LOG.warn is deprecated")')))
+        self.assertTrue(list(checks.no_log_warn(
+            'LOG.warn("LOG.warn is deprecated")')))

tox.ini

@@ -370,6 +370,7 @@ extension =
   T115 = checks:dont_put_admin_tests_on_nonadmin_path
   T116 = checks:unsupported_exception_attribute_PY3
   T117 = checks:negative_test_attribute_always_applied_to_negative_tests
+  T118 = checks:no_log_warn
 paths =
   ./tempest/hacking