hacking: Add check for deprecated exception types

We also move everything to a new module with no external imports so
flake8 can import it without needing to install all the dependencies of
openstacksdk.

Change-Id: I8e610bc196f530223b27a6fbb8e8ca11b6420b82
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

openstack/_hacking/checks.py

@@ -12,6 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import os
 import re
 
 from hacking import core
@@ -26,7 +27,7 @@ Guidelines for writing new hacking checks
  - Keep the test method code in the source file ordered based
    on the O3xx value.
  - List the new rule in the top level HACKING.rst file
- - Add test cases for each new rule to nova/tests/unit/test_hacking.py
+ - Add test cases for each new rule to openstack/tests/unit/test_hacking.py
 
 """
 
@@ -41,3 +42,23 @@ def assert_no_setupclass(logical_line):
     """
     if SETUPCLASS_RE.match(logical_line):
         yield (0, "O300: setUpClass not allowed")
+
+
+@core.flake8ext
+def assert_no_deprecated_exceptions(logical_line, filename):
+    """Check for use of deprecated cloud-layer exceptions
+
+    0310
+    """
+    if filename.endswith(os.path.join('openstack', 'cloud', 'exc.py')):
+        return
+
+    for exception in (
+        'OpenStackCloudTimeout',
+        'OpenStackCloudHTTPError',
+        'OpenStackCloudBadRequest',
+        'OpenStackCloudURINotFound',
+        'OpenStackCloudResourceNotFound',
+    ):
+        if re.search(fr'\b{exception}\b', logical_line):
+            yield (0, 'O310: Use of deprecated Exception class')

openstack/cloud/exc.py

@@ -37,7 +37,7 @@ class OpenStackCloudUnavailableFeature(OpenStackCloudException):
     pass
 
 
-# Backwards compat
+# Backwards compat. These are deprecated and should not be used in new code.
 OpenStackCloudTimeout = exceptions.ResourceTimeout
 OpenStackCloudHTTPError = exceptions.HttpException
 OpenStackCloudBadRequest = exceptions.BadRequestException

openstack/tests/unit/test_hacking.py

@@ -12,7 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from openstack import _hacking
+from openstack._hacking import checks
 from openstack.tests.unit import base
 
 
@@ -52,20 +52,45 @@ class HackingTestCase(base.TestCase):
 
     def test_assert_no_setupclass(self):
         self.assertEqual(
-            len(list(_hacking.assert_no_setupclass("def setUpClass(cls)"))), 1
+            len(list(checks.assert_no_setupclass("def setUpClass(cls)"))), 1
         )
 
         self.assertEqual(
-            len(list(_hacking.assert_no_setupclass("# setUpClass is evil"))), 0
+            len(list(checks.assert_no_setupclass("# setUpClass is evil"))), 0
         )
 
         self.assertEqual(
             len(
                 list(
-                    _hacking.assert_no_setupclass(
+                    checks.assert_no_setupclass(
                         "def setUpClassyDrinkingLocation(cls)"
                     )
                 )
             ),
             0,
         )
+
+    def test_assert_no_deprecated_exceptions(self):
+        self.assertEqual(
+            len(
+                list(
+                    checks.assert_no_deprecated_exceptions(
+                        "raise exc.OpenStackCloudTimeout",
+                        "openstack/cloud/compute.py",
+                    )
+                )
+            ),
+            1,
+        )
+
+        self.assertEqual(
+            len(
+                list(
+                    checks.assert_no_deprecated_exceptions(
+                        "raise exc.OpenStackCloudTimeout",
+                        "openstack/cloud/exc.py",
+                    )
+                )
+            ),
+            0,
+        )

tox.ini

@@ -159,8 +159,9 @@ exclude = .venv,.git,.tox,dist,doc,*lib/python*,*egg,build,openstack/_services_m
 
 [flake8:local-plugins]
 extension =
-  O300 = _hacking:assert_no_setupclass
-paths = ./openstack
+  O300 = checks:assert_no_setupclass
+  O310 = checks:assert_no_deprecated_exceptions
+paths = ./openstack/_hacking
 
 [doc8]
 extensions = .rst, .yaml