Remove custom arguments in object.__new__ of BaseInstrumentor (#1439)

* Add a test case to reproduce the issue

* Fix the class initialization when parameters are provided

* Update CHANGELOG.md

* Fix linting issues

* Additional test case which inits SystemMetricsInstrumentor twice

* Updated linting following update to black style

* Moved changelog entry to unreleased section

---------

Co-authored-by: Srikanth Chekuri <[email protected]>
Co-authored-by: Diego Hurtado <[email protected]>
Co-authored-by: Leighton Chen <[email protected]>

Author: 4 people

CHANGELOG.md

@@ -24,6 +24,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Fix Flask instrumentation to only close the span if it was created by the same thread.
   ([#1654](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1654))
+- `opentelemetry-instrumentation-system-metrics` Fix initialization of the instrumentation class when configuration is provided
+  ([#1438](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1439))
 
 ## Version 1.16.0/0.37b0 (2023-02-17)
 

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

@@ -61,11 +61,31 @@ def setUp(self):
         )
         self._patch_net_connections.start()
 
+        # Reset the singleton class on each test run
+        SystemMetricsInstrumentor._instance = None
+
     def tearDown(self):
         super().tearDown()
         self._patch_net_connections.stop()
         SystemMetricsInstrumentor().uninstrument()
 
+    def test_system_metrics_instrumentor_initialization(self):
+        try:
+            SystemMetricsInstrumentor()
+            SystemMetricsInstrumentor(config={})
+        except Exception as error:  # pylint: disable=broad-except
+            self.fail(f"Unexpected exception {error} raised")
+
+        SystemMetricsInstrumentor._instance = None
+
+        try:
+            SystemMetricsInstrumentor(config={})
+            SystemMetricsInstrumentor()
+        except Exception as error:  # pylint: disable=broad-except
+            self.fail(f"Unexpected exception {error} raised")
+
+        SystemMetricsInstrumentor().instrument()
+
     def test_system_metrics_instrument(self):
         reader = InMemoryMetricReader()
         meter_provider = MeterProvider(metric_readers=[reader])
@@ -103,6 +123,35 @@ def test_system_metrics_instrument(self):
             self.assertIn(observer, observer_names)
             observer_names.remove(observer)
 
+    def test_runtime_metrics_instrument(self):
+        runtime_config = {
+            "runtime.memory": ["rss", "vms"],
+            "runtime.cpu.time": ["user", "system"],
+            "runtime.gc_count": None,
+        }
+
+        reader = InMemoryMetricReader()
+        meter_provider = MeterProvider(metric_readers=[reader])
+        runtime_metrics = SystemMetricsInstrumentor(config=runtime_config)
+        runtime_metrics.instrument(meter_provider=meter_provider)
+
+        metric_names = []
+        for resource_metrics in reader.get_metrics_data().resource_metrics:
+            for scope_metrics in resource_metrics.scope_metrics:
+                for metric in scope_metrics.metrics:
+                    metric_names.append(metric.name)
+        self.assertEqual(len(metric_names), 3)
+
+        observer_names = [
+            f"runtime.{self.implementation}.memory",
+            f"runtime.{self.implementation}.cpu_time",
+            f"runtime.{self.implementation}.gc_count",
+        ]
+
+        for observer in metric_names:
+            self.assertIn(observer, observer_names)
+            observer_names.remove(observer)
+
     def _assert_metrics(self, observer_name, reader, expected):
         assertions = 0
         # pylint: disable=too-many-nested-blocks

opentelemetry-instrumentation/src/opentelemetry/instrumentation/instrumentor.py

@@ -47,7 +47,7 @@ class BaseInstrumentor(ABC):
 
     def __new__(cls, *args, **kwargs):
         if cls._instance is None:
-            cls._instance = object.__new__(cls, *args, **kwargs)
+            cls._instance = object.__new__(cls)
 
         return cls._instance