opentelemetry-sdk: activate instrumentors from declarative config

.changelog/5372.added

@@ -0,0 +1 @@
+`opentelemetry-sdk`: Add support for activating instrumentors from a declarative configuration file via the `instrumentation/development.python` section. Instrumentors can declare a `configuration` attribute to have their options validated through the same type-coercion pipeline used for SDK component configuration.

docs/examples/declarative-config/README.rst

@@ -16,14 +16,15 @@ The source files of this example are available :scm_web:`here
 <docs/examples/declarative-config/>`.
 
 Install the SDK with the ``file-configuration`` extra (it pulls in ``pyyaml``
-and ``jsonschema``), the auto-instrumentation entry point, and the OTLP/HTTP
-exporter:
+and ``jsonschema``), the auto-instrumentation entry point, the OTLP/HTTP
+exporter, and the ``requests`` instrumentation used by this example:
 
 .. code-block:: sh
 
     pip install "opentelemetry-sdk[file-configuration]" \
         opentelemetry-distro \
-        opentelemetry-exporter-otlp-proto-http
+        opentelemetry-exporter-otlp-proto-http \
+        opentelemetry-instrumentation-requests
 
 Start an OTLP-capable backend locally so there is somewhere to send data. Write
 the following file:
@@ -74,7 +75,10 @@ auto-instrumentation apply it. No configuration code lives in ``app.py``:
     export OTEL_CONFIG_FILE=$(pwd)/otel-config.yaml
     opentelemetry-instrument python app.py
 
-You should see the exported span in the Collector's debug output.
+You should see the exported span in the Collector's debug output. The
+``instrumentation/development.python`` section in ``otel-config.yaml``
+activates the ``requests`` instrumentation so outgoing HTTP calls made by
+``app.py`` are automatically traced without any code changes.
 
 Environment variable substitution
 ----------------------------------

docs/examples/declarative-config/otel-config.yaml

@@ -32,3 +32,8 @@ logger_provider:
         exporter:
           otlp_http:
             endpoint: http://localhost:4318/v1/logs
+
+instrumentation/development:
+  python:
+    requests:
+      enabled: true

docs/sdk/configuration.rst

@@ -95,6 +95,31 @@ OTLP/HTTP. The source is available :scm_web:`here
                   - name: api-key
                     value: ${OTLP_API_KEY}
 
+Instrumentation
+---------------
+
+The ``instrumentation/development.python`` section activates Python
+instrumentors by their ``opentelemetry_instrumentor`` entry-point name. Set
+``enabled: false`` to suppress an instrumentor without removing its entry, and
+pass any other keys as keyword arguments to ``instrument()``:
+
+.. code-block:: yaml
+
+    instrumentation/development:
+      python:
+        requests:
+          enabled: true
+        urllib3:
+          enabled: true
+          max_spans_per_request: 10
+
+If the instrumentor class declares a ``configuration`` class attribute pointing
+to a dataclass, the options are validated and type-coerced through the same
+pipeline used for SDK component configuration before being forwarded to
+``instrument()``. Instrumentors that are already active (for example because
+``opentelemetry-instrument`` ran before the file was applied) are silently
+skipped.
+
 Environment variable substitution
 ----------------------------------
 

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

@@ -11,12 +11,11 @@
 
 from __future__ import annotations
 
-import dataclasses
-import enum
-import types
-import typing
 from collections.abc import Mapping
-from typing import Any, TypeVar, get_args, get_origin
+from dataclasses import fields, is_dataclass
+from enum import Enum
+from types import UnionType
+from typing import Any, TypeVar, Union, get_args, get_origin, get_type_hints
 
 _T = TypeVar("_T")
 
@@ -27,7 +26,7 @@ def _unwrap_optional(type_hint: Any) -> Any:
     Returns the unwrapped type, or the original hint if not a union with None.
     """
     origin = get_origin(type_hint)
-    if origin is types.UnionType or origin is typing.Union:
+    if origin is UnionType or origin is Union:
         non_none = [t for t in get_args(type_hint) if t is not type(None)]
         if len(non_none) == 1:
             return non_none[0]
@@ -58,15 +57,15 @@ def _convert_value(value: Any, type_hint: Any) -> Any:
     # Direct dataclass type — recurse
     if (
         isinstance(unwrapped, type)
-        and dataclasses.is_dataclass(unwrapped)
+        and is_dataclass(unwrapped)
         and isinstance(value, dict)
     ):
         return _dict_to_dataclass(value, unwrapped)
 
     # Enum type — coerce string/value to the Enum member
     if (
         isinstance(unwrapped, type)
-        and issubclass(unwrapped, enum.Enum)
+        and issubclass(unwrapped, Enum)
         and not isinstance(value, unwrapped)
     ):
         return unwrapped(value)
@@ -90,22 +89,28 @@ def _dict_to_dataclass(data: Mapping[str, Any], cls: type[_T]) -> _T:
     Raises:
         TypeError: If ``cls`` is not a dataclass type.
     """
-    if not dataclasses.is_dataclass(cls):
+    if not is_dataclass(cls):
         raise TypeError(f"{cls.__name__} is not a dataclass")
 
     # Annotated as ``dict[str, Any]`` so astroid stops tracing into
-    # ``typing.get_type_hints`` — under pylint 3.x that path leads into
+    # ``get_type_hints`` — under pylint 3.x that path leads into
     # Python 3.14's ``annotationlib`` (which uses t-strings) and crashes.
-    hints: dict[str, Any] = dict(
-        typing.get_type_hints(cls, include_extras=False)
-    )
-    known_fields = {f.name for f in dataclasses.fields(cls)}
+    hints: dict[str, Any] = dict(get_type_hints(cls, include_extras=False))
+    known_fields = {f.name for f in fields(cls)}
     kwargs: dict[str, Any] = {}
 
     for key, value in data.items():
-        if key in known_fields:
-            type_hint = hints.get(key)
-            kwargs[key] = _convert_value(value, type_hint)
+        # The OTel configuration schema uses "/" as a namespace separator for
+        # development/experimental features (e.g. "otlp_file/development",
+        # "instrumentation/development").  Python identifiers cannot contain
+        # "/", so the corresponding dataclass fields use "_" instead (e.g.
+        # "otlp_file_development").  Without this normalisation the key would
+        # not match any known field and would fall through to
+        # additional_properties, causing the factory lookup to fail silently.
+        field_key = key.replace("/", "_")
+        if field_key in known_fields:
+            type_hint = hints.get(field_key)
+            kwargs[field_key] = _convert_value(value, type_hint)
         else:
             # Unknown key — @_additional_properties decorator will capture it.
             kwargs[key] = value

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

@@ -10,7 +10,7 @@
 
 from __future__ import annotations
 
-import logging
+from logging import getLogger
 
 from opentelemetry.sdk._configuration._logger_provider import (
     configure_logger_provider,
@@ -23,9 +23,12 @@
 from opentelemetry.sdk._configuration._tracer_provider import (
     configure_tracer_provider,
 )
+from opentelemetry.sdk._configuration.instrumentation import (
+    configure_instrumentation,
+)
 from opentelemetry.sdk._configuration.models import OpenTelemetryConfiguration
 
-_logger = logging.getLogger(__name__)
+_logger = getLogger(__name__)
 
 
 def configure_sdk(config: OpenTelemetryConfiguration) -> None:
@@ -62,3 +65,4 @@ def configure_sdk(config: OpenTelemetryConfiguration) -> None:
     configure_meter_provider(config.meter_provider, resource)
     configure_logger_provider(config.logger_provider, resource)
     configure_propagator(config.propagator)
+    configure_instrumentation(config.instrumentation_development)

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

@@ -0,0 +1,78 @@
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+
+from __future__ import annotations
+
+from dataclasses import fields, is_dataclass
+from inspect import isclass
+from logging import getLogger
+
+from opentelemetry.sdk._configuration._common import load_entry_point
+from opentelemetry.sdk._configuration._conversion import _dict_to_dataclass
+from opentelemetry.sdk._configuration._exceptions import ConfigurationError
+from opentelemetry.sdk._configuration.models import ExperimentalInstrumentation
+
+_logger = getLogger(__name__)
+
+
+def configure_instrumentation(
+    configuration: ExperimentalInstrumentation | None,
+) -> None:
+    """Activate instrumentors listed under ``instrumentation/development.python``.
+
+    For each entry in ``configuration.python`` the matching
+    ``opentelemetry_instrumentor`` entry point is loaded.  If the instrumentor
+    class exposes a ``configuration`` attribute that is a dataclass type, the
+    raw options are validated through ``_dict_to_dataclass`` before being
+    forwarded to ``instrument()``.  An ``enabled: false`` value suppresses
+    instrumentation without raising.
+
+    If an instrumentor is already active (e.g. ``opentelemetry-instrument``
+    ran before the SDK was configured from the file) its ``instrument()`` call
+    is skipped to avoid a double-instrumentation warning.
+
+    Absent or unknown entry points are logged as warnings; runtime errors from
+    an instrumentor are logged as exceptions.  Neither stops the remaining
+    instrumentors from being applied.
+    """
+    if configuration is None or configuration.python is None:
+        return
+
+    for name, options in configuration.python.items():
+        options = dict(options)
+        if not options.pop("enabled", True):
+            _logger.debug(
+                "Instrumentation '%s' is disabled in declarative config; skipping",
+                name,
+            )
+            continue
+
+        try:
+            cls = load_entry_point("opentelemetry_instrumentor", name)
+            configuration_cls = getattr(cls, "configuration", None)
+            if isclass(configuration_cls) and is_dataclass(configuration_cls):
+                configuration_obj = _dict_to_dataclass(
+                    options, configuration_cls
+                )
+                options = {
+                    f.name: value
+                    for f in fields(configuration_obj)
+                    if (value := getattr(configuration_obj, f.name))
+                    is not None
+                }
+            instance = cls()
+            if getattr(instance, "is_instrumented_by_opentelemetry", False):
+                _logger.debug("Skipping '%s': already instrumented", name)
+            else:
+                instance.instrument(**options)
+                _logger.debug("Instrumented '%s' via declarative config", name)
+        except ConfigurationError as exc:
+            _logger.warning(
+                "Skipping instrumentation '%s' in declarative config: %s",
+                name,
+                exc,
+            )
+        except Exception:  # pylint: disable=broad-except
+            _logger.exception(
+                "Failed to instrument '%s' via declarative config", name
+            )