opentelemetry-sdk: sketch of an OpAMP integration

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

@@ -491,6 +491,18 @@ def _import_id_generator(id_generator_name: str) -> IdGenerator:
     raise RuntimeError(f"{id_generator_name} is not an IdGenerator")
 
 
+def _import_opamp() -> callable[[...], None]:
+    # this in development, at the moment we are looking for a callable that takes
+    # the resource and instantiate an OpAMP agent.
+    # Since configuration is not specified every implementors may have its own.
+    # Refer to opentelemetry-opamp-client package on how to setup the OpAMP agent.
+    _, opamp_init_func = _import_config_components(
+        ["init_function"], "_opentelemetry_opamp"
+    )[0]
+
+    return opamp_init_func
+
+
 def _initialize_components(
     auto_instrumentation_version: str | None = None,
     trace_exporter_names: list[str] | None = None,
@@ -543,6 +555,17 @@ def _initialize_components(
     # from the env variable else defaults to "unknown_service"
     resource = Resource.create(resource_attributes)
 
+    # OpAMP is a system created to configure OpenTelemetry SDKs with a remote config.
+    # This is different than other init helpers because setting up OpAMP requires distro
+    # provided code as it's not strictly specified. We call OpAMP init before other code
+    # because people may want to have it blocking to get an updated config before setting
+    # up the rest of the SDK.
+    try:
+        _init_opamp = _import_opamp()
+        _init_opamp(resource=resource)
+    except RuntimeError:
+        _logger.debug("No OpAMP init function found")
+
     _init_tracing(
         exporters=span_exporters,
         id_generator=id_generator,

opentelemetry-sdk/tests/test_configurator.py

@@ -1438,3 +1438,33 @@ def f(x):
         self.assertEqual(logging.config.dictConfig.__name__, "dictConfig")
         self.assertEqual(logging.basicConfig.__name__, "basicConfig")
         self.assertEqual(logging.config.fileConfig.__name__, "fileConfig")
+
+
+class TestOpAMPInit(TestCase):
+    @patch("opentelemetry.sdk._configuration.entry_points")
+    @patch("opentelemetry.sdk._configuration.Resource")
+    def test_init_function_found(self, mock_resource, mock_entry_points):
+        init_function = mock.Mock()
+        mock_entry_points.configure_mock(
+            return_value=[IterEntryPoint("init_function", init_function)]
+        )
+
+        _initialize_components(id_generator=1)
+
+        mock_entry_points.assert_has_calls(
+            [mock.call(group="_opentelemetry_opamp", name="init_function")]
+        )
+        init_function.assert_called_once_with(
+            resource=mock_resource.create.return_value
+        )
+
+    @patch("opentelemetry.sdk._configuration.entry_points")
+    def test_init_function_not_found(self, mock_entry_points):
+        mock_entry_points.configure_mock(return_value=[])
+
+        with self.assertLogs(level="DEBUG") as cm:
+            _initialize_components(id_generator=1)
+        self.assertIn(
+            "DEBUG:opentelemetry.sdk._configuration:No OpAMP init function found",
+            cm.output,
+        )