Add typing

Change-Id: I75d8e9603ae12aa89fe465ce438dd79fa475e48e
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

.pre-commit-config.yaml

@@ -13,7 +13,7 @@ repos:
       - id: check-yaml
         files: .*\.(yaml|yml)$
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.14.7
+    rev: v0.14.8
     hooks:
       - id: ruff-check
         args: ['--fix', '--unsafe-fixes']

oslo_metrics/__main__.py

@@ -19,11 +19,13 @@ import signal
 import socket
 import sys
 import threading
+from types import FrameType
+from typing import Any
 from wsgiref.simple_server import make_server
 from wsgiref.simple_server import WSGIRequestHandler
 
-from oslo_config import cfg
-from oslo_log import log as logging
+from oslo_config import cfg  # type: ignore
+from oslo_log import log as logging  # type: ignore
 from prometheus_client import make_wsgi_app
 
 from oslo_metrics import message_router
@@ -63,7 +65,7 @@ logging.setup(CONF, 'oslo-metrics')
 
 
 class MetricsListener:
-    def __init__(self, socket_path):
+    def __init__(self, socket_path: str) -> None:
         self.socket_path = socket_path
         self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
         self.unlink(socket_path)
@@ -72,14 +74,14 @@ class MetricsListener:
         self.start = True
         self.router = message_router.MessageRouter()
 
-    def unlink(self, socket_path):
+    def unlink(self, socket_path: str) -> None:
         try:
             os.unlink(socket_path)
         except OSError:
             if os.path.exists(socket_path):
                 raise
 
-    def serve(self):
+    def serve(self) -> None:
         while self.start:
             readable, writable, exceptional = select.select(
                 [self.socket], [], [], 1
@@ -95,7 +97,7 @@ class MetricsListener:
             except TimeoutError:
                 pass
 
-    def stop(self):
+    def stop(self) -> None:
         self.socket.close()
         self.start = False
 
@@ -103,20 +105,24 @@ class MetricsListener:
 class _SilentHandler(WSGIRequestHandler):
     """WSGI handler that does not log requests."""
 
-    def log_message(self, format, *args):
+    def log_message(self, format: str, *args: Any) -> None:
         """Log nothing."""
 
 
 httpd = None
 
 
-def handle_sigterm(_signum, _frame):
+def handle_sigterm(_signum: int, _frame: FrameType | None) -> None:
+    if httpd is None:
+        # this should never happen
+        raise RuntimeError('httpd is uninitialized')
+
     LOG.debug("Caught sigterm")
     shutdown_thread = threading.Thread(target=httpd.shutdown)
     shutdown_thread.start()
 
 
-def main():
+def main() -> None:
     cfg.CONF(sys.argv[1:])
     socket_path = cfg.CONF.oslo_metrics.metrics_socket_file
     m = MetricsListener(socket_path)
@@ -129,18 +135,21 @@ def main():
     mt.start()
 
     app = make_wsgi_app()
+
+    global httpd
+    if cfg.CONF.oslo_metrics.wsgi_silent_server:
+        httpd = make_server(
+            '',
+            CONF.oslo_metrics.prometheus_port,
+            app,
+            handler_class=_SilentHandler,
+        )
+    else:
+        httpd = make_server('', CONF.oslo_metrics.prometheus_port, app)
+
+    signal.signal(signal.SIGTERM, handle_sigterm)
+
     try:
-        global httpd
-        if cfg.CONF.oslo_metrics.wsgi_silent_server:
-            httpd = make_server(
-                '',
-                CONF.oslo_metrics.prometheus_port,
-                app,
-                handler_class=_SilentHandler,
-            )
-        else:
-            httpd = make_server('', CONF.oslo_metrics.prometheus_port, app)
-        signal.signal(signal.SIGTERM, handle_sigterm)
         httpd.serve_forever()
     except KeyboardInterrupt:
         pass

oslo_metrics/message_router.py

@@ -13,7 +13,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from oslo_log import log as logging
+from oslo_log import log as logging  # type: ignore
 from oslo_utils import importutils
 
 from oslo_metrics import message_type
@@ -25,7 +25,7 @@ MODULE_LISTS = ["oslo_metrics.metrics.oslo_messaging"]
 
 
 class MessageRouter:
-    def __init__(self):
+    def __init__(self) -> None:
         self.modules = {}
         for m_str in MODULE_LISTS:
             mod = importutils.try_import(m_str, False)
@@ -33,14 +33,14 @@ class MessageRouter:
                 LOG.error("Failed to load module %s", m_str)
             self.modules[m_str.split('.')[-1]] = mod
 
-    def process(self, raw_string):
+    def process(self, raw_string: bytes) -> None:
         try:
             metric = message_type.Metric.from_json(raw_string.decode())
             self.dispatch(metric)
         except Exception as e:
             LOG.error("Failed to parse: %s", e)
 
-    def dispatch(self, metric):
+    def dispatch(self, metric: message_type.Metric) -> None:
         if metric.module not in self.modules:
             LOG.error("Failed to lookup modules by %s", metric.module)
             return

oslo_metrics/message_type.py

@@ -14,22 +14,28 @@
 # under the License.
 
 import json
+from typing import Any, TypedDict
 
 
 class UnSupportedMetricActionError(Exception):
-    def __init__(self, message=None):
+    def __init__(self, message: str | None = None) -> None:
         self.message = message
 
 
 class MetricValidationError(Exception):
-    def __init__(self, message=None):
+    def __init__(self, message: str | None = None) -> None:
         self.message = message
 
 
+class _MetricActionDict(TypedDict, total=False):
+    action: str
+    value: str
+
+
 class MetricAction:
     actions = ['inc', 'observe']
 
-    def __init__(self, action, value):
+    def __init__(self, action: str, value: str) -> None:
         if action not in self.actions:
             raise UnSupportedMetricActionError(
                 f"{action} action is not supported"
@@ -38,7 +44,7 @@ class MetricAction:
         self.value = value
 
     @classmethod
-    def validate(cls, metric_action_dict):
+    def validate(cls, metric_action_dict: _MetricActionDict) -> None:
         if "value" not in metric_action_dict:
             raise MetricValidationError("action need 'value' field")
         if "action" not in metric_action_dict:
@@ -49,18 +55,22 @@ class MetricAction:
             )
 
     @classmethod
-    def from_dict(cls, metric_action_dict):
+    def from_dict(
+        cls, metric_action_dict: _MetricActionDict
+    ) -> 'MetricAction':
         return cls(metric_action_dict["action"], metric_action_dict["value"])
 
 
 class Metric:
-    def __init__(self, module, name, action, **labels):
+    def __init__(
+        self, module: str, name: str, action: MetricAction, **labels: str
+    ) -> None:
         self.module = module
         self.name = name
         self.action = action
         self.labels = labels
 
-    def to_json(self):
+    def to_json(self) -> str:
         raw = {
             "module": self.module,
             "name": self.name,
@@ -73,7 +83,7 @@ class Metric:
         return json.dumps(raw)
 
     @classmethod
-    def from_json(cls, encoded):
+    def from_json(cls, encoded: str) -> 'Metric':
         metric_dict = json.loads(encoded)
         cls._validate(metric_dict)
         return Metric(
@@ -84,7 +94,7 @@ class Metric:
         )
 
     @classmethod
-    def _validate(cls, metric_dict):
+    def _validate(cls, metric_dict: dict[str, Any]) -> None:
         if "module" not in metric_dict:
             raise MetricValidationError("module should be specified")
 

oslo_metrics/tests/test_message_process.py

@@ -13,13 +13,14 @@
 """
 test_message_process
 --------------------
+
 Check that messages are processed correctly
 """
 
 from unittest import mock
 
 from oslo_metrics import message_router
-from oslotest import base
+from oslotest import base  # type: ignore
 import prometheus_client
 
 

oslo_metrics/tests/test_message_validation.py

@@ -12,13 +12,16 @@
 
 """
 test_message_validation
---------------------
+-----------------------
+
 Check that messages validation is working properly
 """
 
 import json
+from typing import Any
+
 from oslo_metrics import message_type
-from oslotest import base
+from oslotest import base  # type: ignore
 
 
 class TestMetricValidation(base.BaseTestCase):
@@ -29,11 +32,14 @@ class TestMetricValidation(base.BaseTestCase):
         try:
             func(*args, **kwargs)
             self.assertFail()
-        except Exception as e:
+        except (
+            message_type.MetricValidationError,
+            message_type.UnSupportedMetricActionError,
+        ) as e:
             self.assertEqual(message, e.message)
 
     def test_message_validation(self):
-        metric = {}
+        metric: dict[str, Any] = {}
         message = "module should be specified"
         self.assertRaisesWithMessage(
             message, message_type.Metric.from_json, json.dumps(metric)

pyproject.toml

@@ -37,6 +37,20 @@ Repository = "https://opendev.org/openstack/oslo.metrics"
 [tool.setuptools]
 packages = ["oslo_metrics"]
 
+[tool.mypy]
+python_version = "3.10"
+show_column_numbers = true
+show_error_context = true
+strict = true
+exclude = '(?x)(doc | examples | releasenotes)'
+
+[[tool.mypy.overrides]]
+module = ["oslo_metrics.tests.*"]
+disallow_untyped_calls = false
+disallow_untyped_defs = false
+disallow_subclassing_any = false
+disallow_any_generics = false
+
 [tool.ruff]
 line-length = 79
 

tox.ini

@@ -7,17 +7,30 @@ allowlist_externals =
   find
 deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
 commands =
   find . -type f -name "*.pyc" -delete
   stestr run --slowest {posargs}
 
 [testenv:pep8]
-skip_install = true
+description =
+  Run style checks.
 deps =
   pre-commit
+  {[testenv:mypy]deps}
 commands =
   pre-commit run -a
+  {[testenv:mypy]commands}
+
+[testenv:mypy]
+description =
+  Run type checks.
+deps =
+  {[testenv]deps}
+  mypy
+commands =
+  mypy --cache-dir="{envdir}/mypy_cache" {posargs:oslo_metrics}
 
 [testenv:venv]
 commands = {posargs}
@@ -49,6 +62,7 @@ enable-extensions = H904
 
 [hacking]
 import_exceptions =
+  typing
 
 [testenv:releasenotes]
 allowlist_externals =