Merge branch 'main' into reinit_metrics_on_fork

Author: MikeGoldsmith

CHANGELOG.md

@@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - `opentelemetry-sdk`: Add fork-safety to metrics `SynchronousMeasurementConsumer` by registering a post-fork child hook, lazily reinitializing metric reader storages on first use in the child process, and clearing asynchronous instruments to avoid duplicated state after `fork()`
   ([#4767](https://github.com/open-telemetry/opentelemetry-python/pull/4767))
+- `opentelemetry-sdk`: Add `service` resource detector support to declarative file configuration via `detection_development.detectors[].service`
+  ([#5003](https://github.com/open-telemetry/opentelemetry-python/pull/5003))
 
 ## Version 1.41.0/0.62b0 (2026-04-09)
 

eachdist.ini

@@ -35,6 +35,7 @@ packages=
     opentelemetry-exporter-opencensus
     opentelemetry-exporter-prometheus
     opentelemetry-distro
+    opentelemetry-proto-json
     opentelemetry-semantic-conventions
     opentelemetry-test-utils
     tests

opentelemetry-sdk/benchmarks/trace/test_benchmark_trace.py

@@ -80,7 +80,7 @@ def tracer_configurator(tracer_scope):
                 for i in range(num_tracer_configurator_rules)
             ],
             default_config=_TracerConfig(is_enabled=True),
-        )(tracer_scope=tracer_scope)
+        )(tracer_scope)
 
     tracer_provider._set_tracer_configurator(
         tracer_configurator=tracer_configurator

opentelemetry-sdk/src/opentelemetry/sdk/_configuration/_resource.py

@@ -16,6 +16,8 @@
 
 import fnmatch
 import logging
+import os
+import uuid
 from typing import Callable, Optional
 from urllib import parse
 
@@ -28,6 +30,8 @@
 from opentelemetry.sdk._configuration.models import Resource as ResourceConfig
 from opentelemetry.sdk.resources import (
     _DEFAULT_RESOURCE,
+    OTEL_SERVICE_NAME,
+    SERVICE_INSTANCE_ID,
     SERVICE_NAME,
     ProcessResourceDetector,
     Resource,
@@ -152,6 +156,15 @@ def _run_detectors(
     is updated in-place; later detectors overwrite earlier ones for the
     same key.
     """
+    if detector_config.service is not None:
+        attrs: dict[str, object] = {
+            SERVICE_INSTANCE_ID: str(uuid.uuid4()),
+        }
+        service_name = os.environ.get(OTEL_SERVICE_NAME)
+        if service_name:
+            attrs[SERVICE_NAME] = service_name
+        detected_attrs.update(attrs)
+
     if detector_config.host is not None:
         detected_attrs.update(_HostResourceDetector().detect().attributes)
 

opentelemetry-sdk/tests/_configuration/test_resource.py

@@ -33,6 +33,7 @@
     HOST_NAME,
     PROCESS_PID,
     PROCESS_RUNTIME_NAME,
+    SERVICE_INSTANCE_ID,
     SERVICE_NAME,
     TELEMETRY_SDK_LANGUAGE,
     TELEMETRY_SDK_NAME,
@@ -307,6 +308,79 @@ def test_attributes_list_invalid_pair_skipped(self):
         self.assertTrue(any("no-equals" in msg for msg in cm.output))
 
 
+class TestServiceResourceDetector(unittest.TestCase):
+    @staticmethod
+    def _config_with_service() -> ResourceConfig:
+        return ResourceConfig(
+            detection_development=ExperimentalResourceDetection(
+                detectors=[ExperimentalResourceDetector(service={})]
+            )
+        )
+
+    def test_service_detector_adds_instance_id(self):
+        resource = create_resource(self._config_with_service())
+        self.assertIn(SERVICE_INSTANCE_ID, resource.attributes)
+
+    def test_service_instance_id_is_unique_per_call(self):
+        r1 = create_resource(self._config_with_service())
+        r2 = create_resource(self._config_with_service())
+        self.assertNotEqual(
+            r1.attributes[SERVICE_INSTANCE_ID],
+            r2.attributes[SERVICE_INSTANCE_ID],
+        )
+
+    def test_service_detector_reads_otel_service_name_env_var(self):
+        with patch.dict(os.environ, {"OTEL_SERVICE_NAME": "my-service"}):
+            resource = create_resource(self._config_with_service())
+        self.assertEqual(resource.attributes[SERVICE_NAME], "my-service")
+
+    def test_service_detector_no_env_var_leaves_default_service_name(self):
+        with patch.dict(os.environ, {}, clear=True):
+            resource = create_resource(self._config_with_service())
+        self.assertEqual(resource.attributes[SERVICE_NAME], "unknown_service")
+
+    def test_explicit_service_name_overrides_env_var(self):
+        """Config attributes win over the service detector's env-var value."""
+        config = ResourceConfig(
+            attributes=[
+                AttributeNameValue(name="service.name", value="explicit-svc")
+            ],
+            detection_development=ExperimentalResourceDetection(
+                detectors=[ExperimentalResourceDetector(service={})]
+            ),
+        )
+        with patch.dict(os.environ, {"OTEL_SERVICE_NAME": "env-svc"}):
+            resource = create_resource(config)
+        self.assertEqual(resource.attributes[SERVICE_NAME], "explicit-svc")
+
+    def test_service_detector_not_run_when_absent(self):
+        resource = create_resource(ResourceConfig())
+        self.assertNotIn(SERVICE_INSTANCE_ID, resource.attributes)
+
+    def test_service_detector_not_run_when_detection_development_is_none(self):
+        resource = create_resource(ResourceConfig(detection_development=None))
+        self.assertNotIn(SERVICE_INSTANCE_ID, resource.attributes)
+
+    def test_service_detector_also_includes_sdk_defaults(self):
+        resource = create_resource(self._config_with_service())
+        self.assertEqual(resource.attributes[TELEMETRY_SDK_LANGUAGE], "python")
+        self.assertIn(TELEMETRY_SDK_VERSION, resource.attributes)
+
+    def test_included_filter_limits_service_attributes(self):
+        config = ResourceConfig(
+            detection_development=ExperimentalResourceDetection(
+                detectors=[ExperimentalResourceDetector(service={})],
+                attributes=IncludeExclude(included=["service.instance.id"]),
+            )
+        )
+        with patch.dict(os.environ, {"OTEL_SERVICE_NAME": "my-service"}):
+            resource = create_resource(config)
+        self.assertIn(SERVICE_INSTANCE_ID, resource.attributes)
+        # service.name comes from the filter-excluded detector output, but the
+        # default "unknown_service" is still added by create_resource directly
+        self.assertEqual(resource.attributes[SERVICE_NAME], "unknown_service")
+
+
 class TestHostResourceDetector(unittest.TestCase):
     @staticmethod
     def _config_with_host() -> ResourceConfig:

opentelemetry-sdk/tests/trace/test_trace.py

@@ -2231,6 +2231,7 @@ def test_parent_child_span_exception(self):
         exception_type = exception.__class__.__name__
         exception_message = exception.args[0]
 
+        child_span = None
         try:
             with tracer.start_as_current_span(
                 "parent",
@@ -2245,6 +2246,8 @@ def test_parent_child_span_exception(self):
         except Exception:  # pylint: disable=broad-exception-caught
             pass
 
+        self.assertIsNotNone(child_span)
+
         self.assertTrue(child_span.status.is_ok)
         self.assertIsNone(child_span.status.description)
         self.assertTupleEqual(child_span.events, ())
@@ -2275,6 +2278,7 @@ def test_child_parent_span_exception(self):
 
         exception = Exception("exception")
 
+        child_span = None
         try:
             with tracer.start_as_current_span(
                 "parent",
@@ -2290,6 +2294,8 @@ def test_child_parent_span_exception(self):
         except Exception:  # pylint: disable=broad-exception-caught
             pass
 
+        self.assertIsNotNone(child_span)
+
         self.assertTrue(child_span.status.is_ok)
         self.assertIsNone(child_span.status.description)
         self.assertTupleEqual(child_span.events, ())