feat: add experimental logger configurator (#4980)

* feat: add experimental LoggerConfigurator

* update SDK configuration to utilize logger configurator

* generalize rule based configurator

* add safe logger configurator application

* add unit tests

* update CHANGELOG.md

* update type annotation for active loggers

* Address PR comments.

---------

Co-authored-by: Riccardo Magliocchetti <riccardo.magliocchetti@gmail.com>

Author: herin049

CHANGELOG.md

@@ -69,6 +69,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#5007](https://github.com/open-telemetry/opentelemetry-python/pull/5007))
 - Redo OTLPMetricExporter unit tests of `max_export_batch_size` to use real `export`
   ([#5036](https://github.com/open-telemetry/opentelemetry-python/pull/5036))
+- `opentelemetry-sdk`: Implement experimental Logger configurator
+  ([#4980](https://github.com/open-telemetry/opentelemetry-python/pull/4980))
 
 ## Version 1.40.0/0.61b0 (2026-03-04)
 

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

@@ -42,6 +42,7 @@
     LoggingHandler,
     LogRecordProcessor,
 )
+from opentelemetry.sdk._logs._internal import _LoggerConfiguratorT
 from opentelemetry.sdk._logs.export import (
     BatchLogRecordProcessor,
     LogRecordExporter,
@@ -52,6 +53,7 @@
     OTEL_EXPORTER_OTLP_METRICS_PROTOCOL,
     OTEL_EXPORTER_OTLP_PROTOCOL,
     OTEL_EXPORTER_OTLP_TRACES_PROTOCOL,
+    OTEL_PYTHON_LOGGER_CONFIGURATOR,
     OTEL_PYTHON_METER_CONFIGURATOR,
     OTEL_PYTHON_TRACER_CONFIGURATOR,
     OTEL_TRACES_SAMPLER,
@@ -177,6 +179,10 @@ def _get_meter_configurator() -> str | None:
     return environ.get(OTEL_PYTHON_METER_CONFIGURATOR, None)
 
 
+def _get_logger_configurator() -> str | None:
+    return environ.get(OTEL_PYTHON_LOGGER_CONFIGURATOR, None)
+
+
 def _get_exporter_entry_point(
     exporter_name: str, signal_type: Literal["traces", "metrics", "logs"]
 ):
@@ -297,6 +303,7 @@ def _init_metrics(
     set_meter_provider(provider)
 
 
+# pylint: disable-next=too-many-locals
 def _init_logging(
     exporters: dict[str, Type[LogRecordExporter]],
     resource: Resource | None = None,
@@ -305,8 +312,11 @@ def _init_logging(
     log_record_processors: Sequence[LogRecordProcessor] | None = None,
     export_log_record_processor: _ConfigurationExporterLogRecordProcessorT
     | None = None,
+    logger_configurator: _LoggerConfiguratorT | None = None,
 ):
-    provider = LoggerProvider(resource=resource)
+    provider = LoggerProvider(
+        resource=resource, _logger_configurator=logger_configurator
+    )
     set_logger_provider(provider)
 
     exporter_args_map = exporter_args_map or {}
@@ -377,6 +387,27 @@ def overwritten_config_fn(*args, **kwargs):
     logging.basicConfig = wrapper(logging.basicConfig)
 
 
+def _import_logger_configurator(
+    logger_configurator_name: str | None,
+) -> _LoggerConfiguratorT | None:
+    if not logger_configurator_name:
+        return None
+
+    try:
+        _, logger_configurator_impl = _import_config_components(
+            [logger_configurator_name.strip()],
+            "_opentelemetry_logger_configurator",
+        )[0]
+    except Exception as exc:  # pylint: disable=broad-exception-caught
+        _logger.warning(
+            "Using default logger configurator. Failed to load logger configurator, %s: %s",
+            logger_configurator_name,
+            exc,
+        )
+        return None
+    return logger_configurator_impl
+
+
 def _import_tracer_configurator(
     tracer_configurator_name: str | None,
 ) -> _TracerConfiguratorT | None:
@@ -540,6 +571,7 @@ def _initialize_components(
     | None = None,
     tracer_configurator: _TracerConfiguratorT | None = None,
     meter_configurator: _MeterConfiguratorT | None = None,
+    logger_configurator: _LoggerConfiguratorT | None = None,
 ):
     # pylint: disable=too-many-locals
     if trace_exporter_names is None:
@@ -576,6 +608,11 @@ def _initialize_components(
         meter_configurator = _import_meter_configurator(
             meter_configurator_name
         )
+    if logger_configurator is None:
+        logger_configurator_name = _get_logger_configurator()
+        logger_configurator = _import_logger_configurator(
+            logger_configurator_name
+        )
 
     # if env var OTEL_RESOURCE_ATTRIBUTES is given, it will read the service_name
     # from the env variable else defaults to "unknown_service"
@@ -613,6 +650,7 @@ def _initialize_components(
         exporter_args_map=exporter_args_map,
         log_record_processors=log_record_processors,
         export_log_record_processor=export_log_record_processor,
+        logger_configurator=logger_configurator,
     )
 
 

opentelemetry-sdk/src/opentelemetry/sdk/_logs/_internal/__init__.py

@@ -26,7 +26,16 @@
 from os import environ
 from threading import Lock
 from time import time_ns
-from typing import Any, Callable, Tuple, Union, cast, overload  # noqa
+from typing import (  # noqa
+    Any,
+    Callable,
+    Sequence,
+    Tuple,
+    Union,
+    cast,
+    overload,
+)
+from weakref import WeakSet
 
 from typing_extensions import deprecated
 
@@ -51,7 +60,10 @@
 )
 from opentelemetry.sdk.resources import Resource
 from opentelemetry.sdk.util import ns_to_iso_str
-from opentelemetry.sdk.util.instrumentation import InstrumentationScope
+from opentelemetry.sdk.util._configurator import RuleBasedConfigurator
+from opentelemetry.sdk.util.instrumentation import (
+    InstrumentationScope,
+)
 from opentelemetry.semconv._incubating.attributes import code_attributes
 from opentelemetry.semconv.attributes import exception_attributes
 from opentelemetry.trace import (
@@ -63,6 +75,8 @@
 _DEFAULT_OTEL_ATTRIBUTE_COUNT_LIMIT = 128
 _ENV_VALUE_UNSET = ""
 
+_logger = logging.getLogger(__name__)
+
 
 class BytesEncoder(json.JSONEncoder):
     def default(self, o):
@@ -637,6 +651,15 @@ def flush(self) -> None:
             thread.start()
 
 
+@dataclass
+class _LoggerConfig:
+    is_enabled: bool = True
+
+    @classmethod
+    def default(cls) -> _LoggerConfig:
+        return _LoggerConfig()
+
+
 class Logger(APILogger):
     def __init__(
         self,
@@ -648,6 +671,7 @@ def __init__(
         instrumentation_scope: InstrumentationScope,
         *,
         logger_metrics: LoggerMetrics,
+        _logger_config: _LoggerConfig,
     ):
         super().__init__(
             instrumentation_scope.name,
@@ -659,6 +683,17 @@ def __init__(
         self._multi_log_record_processor = multi_log_record_processor
         self._instrumentation_scope = instrumentation_scope
         self._logger_metrics = logger_metrics
+        self._logger_config = _logger_config
+
+    def _is_enabled(self) -> bool:
+        return self._logger_config.is_enabled
+
+    def _set_logger_config(self, logger_config: _LoggerConfig) -> None:
+        self._logger_config = logger_config
+
+    @property
+    def instrumentation_scope(self):
+        return self._instrumentation_scope
 
     @property
     def resource(self):
@@ -681,6 +716,8 @@ def emit(
         """Emits the :class:`ReadWriteLogRecord` by setting instrumentation scope
         and forwarding to the processor.
         """
+        if not self._is_enabled():
+            return
         # If a record is provided, use it directly
         if record is not None:
             if not isinstance(record, ReadWriteLogRecord):
@@ -715,6 +752,22 @@ def emit(
         self._multi_log_record_processor.on_emit(writable_record)
 
 
+_LoggerConfiguratorT = Callable[[InstrumentationScope], _LoggerConfig]
+_RuleBasedLoggerConfigurator = RuleBasedConfigurator[_LoggerConfig]
+
+
+def _default_logger_configurator(
+    _logger_scope: InstrumentationScope,
+) -> _LoggerConfig:
+    return _LoggerConfig.default()
+
+
+def _disable_logger_configurator(
+    _logger_scope: InstrumentationScope,
+) -> _LoggerConfig:
+    return _LoggerConfig(is_enabled=False)
+
+
 class LoggerProvider(APILoggerProvider):
     def __init__(
         self,
@@ -725,6 +778,7 @@ def __init__(
         | None = None,
         *,
         meter_provider: MeterProvider | None = None,
+        _logger_configurator: _LoggerConfiguratorT | None = None,
     ):
         if resource is None:
             self._resource = Resource.create({})
@@ -738,11 +792,16 @@ def __init__(
         )
         disabled = environ.get(OTEL_SDK_DISABLED, "")
         self._disabled = disabled.lower().strip() == "true"
+        self._logger_configurator = (
+            _logger_configurator or _default_logger_configurator
+        )
         self._at_exit_handler = None
         if shutdown_on_exit:
             self._at_exit_handler = atexit.register(self.shutdown)
         self._logger_cache = {}
         self._logger_cache_lock = Lock()
+        self._active_loggers: WeakSet[Logger] = WeakSet()
+        self._active_loggers_lock = Lock()
 
     @property
     def resource(self):
@@ -755,16 +814,14 @@ def _get_logger_no_cache(
         schema_url: str | None = None,
         attributes: _ExtendedAttributes | None = None,
     ) -> Logger:
+        scope = InstrumentationScope(name, version, schema_url, attributes)
+
         return Logger(
             self._resource,
             self._multi_log_record_processor,
-            InstrumentationScope(
-                name,
-                version,
-                schema_url,
-                attributes,
-            ),
+            scope,
             logger_metrics=self._logger_metrics,
+            _logger_config=self._apply_logger_configurator(scope),
         )
 
     def _get_logger_cached(
@@ -797,9 +854,16 @@ def get_logger(
                 schema_url=schema_url,
                 attributes=attributes,
             )
-        if attributes is None:
-            return self._get_logger_cached(name, version, schema_url)
-        return self._get_logger_no_cache(name, version, schema_url, attributes)
+        logger = (
+            self._get_logger_cached(name, version, schema_url)
+            if attributes is None
+            else self._get_logger_no_cache(
+                name, version, schema_url, attributes
+            )
+        )
+        with self._active_loggers_lock:
+            self._active_loggers.add(logger)
+        return logger
 
     def add_log_record_processor(
         self, log_record_processor: LogRecordProcessor
@@ -812,6 +876,38 @@ def add_log_record_processor(
             log_record_processor
         )
 
+    def _set_logger_configurator(
+        self, *, logger_configurator: _LoggerConfiguratorT
+    ):
+        """Set a new LoggerConfigurator for this LoggerProvider.
+
+        Setting a new LoggerConfigurator will result in the configurator being called
+        for each outstanding Logger and for any newly created loggers thereafter.
+        Therefore, it is important that the provided function returns quickly.
+        """
+        self._logger_configurator = logger_configurator
+        with self._active_loggers_lock:
+            for logger in self._active_loggers:
+                # pylint: disable-next=protected-access
+                logger._set_logger_config(
+                    self._apply_logger_configurator(
+                        logger.instrumentation_scope
+                    )
+                )
+
+    def _apply_logger_configurator(
+        self, instrumentation_scope: InstrumentationScope
+    ) -> _LoggerConfig:
+        try:
+            return self._logger_configurator(instrumentation_scope)
+        # pylint: disable-next=broad-exception-caught
+        except Exception:
+            _logger.exception(
+                "logger configurator failed for scope '%s', using default config",
+                instrumentation_scope.name,
+            )
+            return _LoggerConfig.default()
+
     def shutdown(self) -> None:
         """Shuts down the log processors."""
         self._multi_log_record_processor.shutdown()

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

@@ -826,3 +826,15 @@ def channel_credential_provider() -> grpc.ChannelCredentials:
 This is an experimental environment variable and the name of this variable and its behavior can
 change in a non-backwards compatible way.
 """
+
+OTEL_PYTHON_LOGGER_CONFIGURATOR = "OTEL_PYTHON_LOGGER_CONFIGURATOR"
+"""
+.. envvar:: OTEL_PYTHON_LOGGER_CONFIGURATOR
+
+The :envvar:`OTEL_PYTHON_LOGGER_CONFIGURATOR` environment variable allows users to set a
+custom Logger Configurator function.
+Default: opentelemetry.sdk._logs._internal._default_logger_configurator
+
+This is an experimental environment variable and the name of this variable and its behavior can
+change in a non-backwards compatible way.
+"""

opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/__init__.py

@@ -63,9 +63,9 @@
     SdkConfiguration,
 )
 from opentelemetry.sdk.resources import Resource
+from opentelemetry.sdk.util._configurator import RuleBasedConfigurator
 from opentelemetry.sdk.util.instrumentation import (
     InstrumentationScope,
-    _InstrumentationScopePredicateT,
 )
 from opentelemetry.util._once import Once
 from opentelemetry.util.types import (
@@ -414,9 +414,7 @@ def _get_exemplar_filter(exemplar_filter: str) -> ExemplarFilter:
 
 
 _MeterConfiguratorT = Callable[[InstrumentationScope], _MeterConfig]
-_MeterConfiguratorRulesT = Sequence[
-    tuple[_InstrumentationScopePredicateT, _MeterConfig]
-]
+_RuleBasedMeterConfigurator = RuleBasedConfigurator[_MeterConfig]
 
 
 def _default_meter_configurator(
@@ -431,27 +429,6 @@ def _disable_meter_configurator(
     return _MeterConfig(is_enabled=False)
 
 
-class _RuleBasedMeterConfigurator:
-    def __init__(
-        self,
-        *,
-        rules: _MeterConfiguratorRulesT,
-        default_config: _MeterConfig,
-    ):
-        self._rules = rules
-        self._default_config = default_config
-
-    def __call__(self, meter_scope: InstrumentationScope) -> _MeterConfig:
-        for predicate, meter_config in self._rules:
-            if predicate(meter_scope):
-                return meter_config
-        # by default return default config
-        return self._default_config
-
-    def update_rules(self, rules: _MeterConfiguratorRulesT) -> None:
-        self._rules = rules
-
-
 class MeterProvider(APIMeterProvider):
     r"""See `opentelemetry.metrics.MeterProvider`.