opentelemetry-instrumentation-system-metrics: fix running on Google Cloud Run

CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- `opentelemetry-instrumentation-system-metrics`: fix loading on Google Cloud Run
+  ([#3533](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3533))
 - `opentelemetry-instrumentation-fastapi`: fix wrapping of middlewares
   ([#3012](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3012))
 - `opentelemetry-instrumentation-urllib3`: proper bucket boundaries in stable semconv http duration metrics

instrumentation/opentelemetry-instrumentation-system-metrics/src/opentelemetry/instrumentation/system_metrics/__init__.py

@@ -395,7 +395,10 @@ def _instrument(self, **kwargs: Any):
                 self._meter, callbacks=[self._get_cpu_utilization]
             )
 
-        if "process.context_switches" in self._config:
+        if (
+            "process.context_switches" in self._config
+            and self._can_read_context_switches()
+        ):
             self._meter.create_observable_counter(
                 name="process.context_switches",
                 callbacks=[self._get_context_switches],
@@ -482,7 +485,10 @@ def _instrument(self, **kwargs: Any):
                 unit="1",
             )
 
-        if "process.runtime.context_switches" in self._config:
+        if (
+            "process.runtime.context_switches" in self._config
+            and self._can_read_context_switches()
+        ):
             self._meter.create_observable_counter(
                 name=f"process.runtime.{self._python_implementation}.context_switches",
                 callbacks=[self._get_runtime_context_switches],
@@ -493,6 +499,14 @@ def _instrument(self, **kwargs: Any):
     def _uninstrument(self, **kwargs: Any):
         pass
 
+    def _can_read_context_switches(self) -> bool:
+        """On Google Cloud Run psutil is not able to read context switches, catch it before creating the observable instrument"""
+        try:
+            self._proc.num_ctx_switches()
+            return True
+        except NotImplementedError:
+            return False
+
     def _get_open_file_descriptors(
         self, options: CallbackOptions
     ) -> Iterable[Observation]:

instrumentation/opentelemetry-instrumentation-system-metrics/tests/test_system_metrics.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# pylint: disable=protected-access
+# pylint: disable=protected-access,too-many-lines
 
 import sys
 from collections import namedtuple
@@ -235,14 +235,28 @@ def _assert_metrics(self, observer_name, reader, expected):
                                 assertions += 1
         self.assertEqual(len(expected), assertions)
 
-    def _test_metrics(self, observer_name, expected):
+    @staticmethod
+    def _setup_instrumentor() -> InMemoryMetricReader:
         reader = InMemoryMetricReader()
         meter_provider = MeterProvider(metric_readers=[reader])
 
         system_metrics = SystemMetricsInstrumentor()
         system_metrics.instrument(meter_provider=meter_provider)
+        return reader
+
+    def _test_metrics(self, observer_name, expected):
+        reader = self._setup_instrumentor()
         self._assert_metrics(observer_name, reader, expected)
 
+    def _assert_metrics_not_found(self, observer_name):
+        reader = self._setup_instrumentor()
+        seen_metrics = set()
+        for resource_metrics in reader.get_metrics_data().resource_metrics:
+            for scope_metrics in resource_metrics.scope_metrics:
+                for metric in scope_metrics.metrics:
+                    seen_metrics.add(metric.name)
+        self.assertNotIn(observer_name, seen_metrics)
+
     # This patch is added here to stop psutil from raising an exception
     # because we're patching cpu_times
     # pylint: disable=unused-argument
@@ -855,6 +869,14 @@ def test_context_switches(self, mock_process_num_ctx_switches):
         ]
         self._test_metrics("process.context_switches", expected)
 
+    @mock.patch("psutil.Process.num_ctx_switches")
+    def test_context_switches_not_implemented_error(
+        self, mock_process_num_ctx_switches
+    ):
+        mock_process_num_ctx_switches.side_effect = NotImplementedError
+
+        self._assert_metrics_not_found("process.context_switches")
+
     @mock.patch("psutil.Process.num_threads")
     def test_thread_count(self, mock_process_thread_num):
         mock_process_thread_num.configure_mock(**{"return_value": 42})
@@ -947,6 +969,16 @@ def test_runtime_context_switches(self, mock_process_num_ctx_switches):
             f"process.runtime.{self.implementation}.context_switches", expected
         )
 
+    @mock.patch("psutil.Process.num_ctx_switches")
+    def test_runtime_context_switches_not_implemented_error(
+        self, mock_process_num_ctx_switches
+    ):
+        mock_process_num_ctx_switches.side_effect = NotImplementedError
+
+        self._assert_metrics_not_found(
+            f"process.runtime.{self.implementation}.context_switches",
+        )
+
     @mock.patch("psutil.Process.num_threads")
     def test_runtime_thread_count(self, mock_process_thread_num):
         mock_process_thread_num.configure_mock(**{"return_value": 42})