Adds support OTEL_SDK_DISABLED environment variable (#3648)

* Adds support OTEL_SDK_DISABLED environment variable

* Pass schema_url and version to NoOpMeter and NoOpLogger, implement comments from review

* Add CHANGELOG entry

* Fix lint error

* Suppress lint errors due to returning a NoOpTracer when SDK is disabled

---------

Co-authored-by: Leighton Chen <lechen@microsoft.com>
Co-authored-by: Diego Hurtado <ocelotl@users.noreply.github.com>

CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#3751](https://github.com/open-telemetry/opentelemetry-python/pull/3751))
 - bump mypy to 0.982
   ([#3776](https://github.com/open-telemetry/opentelemetry-python/pull/3776))
+- Add support for OTEL_SDK_DISABLED environment variable
+  ([#3648](https://github.com/open-telemetry/opentelemetry-python/pull/3648))
 - Fix ValueError message for PeriodicExportingMetricsReader
   ([#3769](https://github.com/open-telemetry/opentelemetry-python/pull/3769))
 

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

@@ -37,6 +37,7 @@
 from opentelemetry.sdk.environment_variables import (
     OTEL_ATTRIBUTE_COUNT_LIMIT,
     OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT,
+    OTEL_SDK_DISABLED,
 )
 from opentelemetry.sdk.resources import Resource
 from opentelemetry.sdk.util import ns_to_iso_str
@@ -607,6 +608,8 @@ def __init__(
         self._multi_log_record_processor = (
             multi_log_record_processor or SynchronousMultiLogRecordProcessor()
         )
+        disabled = environ.get(OTEL_SDK_DISABLED, "")
+        self._disabled = disabled.lower().strip() == "true"
         self._at_exit_handler = None
         if shutdown_on_exit:
             self._at_exit_handler = atexit.register(self.shutdown)
@@ -621,6 +624,9 @@ def get_logger(
         version: Optional[str] = None,
         schema_url: Optional[str] = None,
     ) -> Logger:
+        if self._disabled:
+            _logger.warning("SDK is disabled.")
+            return NoOpLogger(name, version=version, schema_url=schema_url)
         return Logger(
             self._resource,
             self._multi_log_record_processor,

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

@@ -12,6 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+OTEL_SDK_DISABLED = "OTEL_SDK_DISABLED"
+"""
+.. envvar:: OTEL_SDK_DISABLED
+
+The :envvar:`OTEL_SDK_DISABLED` environment variable disables the SDK for all signals
+Default: "false"
+"""
+
 OTEL_RESOURCE_ATTRIBUTES = "OTEL_RESOURCE_ATTRIBUTES"
 """
 .. envvar:: OTEL_RESOURCE_ATTRIBUTES

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

@@ -14,6 +14,7 @@
 
 from atexit import register, unregister
 from logging import getLogger
+from os import environ
 from threading import Lock
 from time import time_ns
 from typing import Optional, Sequence
@@ -32,6 +33,7 @@
 )
 from opentelemetry.metrics import UpDownCounter as APIUpDownCounter
 from opentelemetry.metrics import _Gauge as APIGauge
+from opentelemetry.sdk.environment_variables import OTEL_SDK_DISABLED
 from opentelemetry.sdk.metrics._internal.exceptions import MetricsTimeoutError
 from opentelemetry.sdk.metrics._internal.instrument import (
     _Counter,
@@ -394,6 +396,8 @@ def __init__(
         self._measurement_consumer = SynchronousMeasurementConsumer(
             sdk_config=self._sdk_config
         )
+        disabled = environ.get(OTEL_SDK_DISABLED, "")
+        self._disabled = disabled.lower().strip() == "true"
 
         if shutdown_on_exit:
             self._atexit_handler = register(self.shutdown)
@@ -512,6 +516,10 @@ def get_meter(
         schema_url: Optional[str] = None,
     ) -> Meter:
 
+        if self._disabled:
+            _logger.warning("SDK is disabled.")
+            return NoOpMeter(name, version=version, schema_url=schema_url)
+
         if self._shutdown:
             _logger.warning(
                 "A shutdown `MeterProvider` can not provide a `Meter`"

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

@@ -49,6 +49,7 @@
     OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT,
     OTEL_EVENT_ATTRIBUTE_COUNT_LIMIT,
     OTEL_LINK_ATTRIBUTE_COUNT_LIMIT,
+    OTEL_SDK_DISABLED,
     OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT,
     OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT,
     OTEL_SPAN_EVENT_COUNT_LIMIT,
@@ -62,7 +63,7 @@
     InstrumentationInfo,
     InstrumentationScope,
 )
-from opentelemetry.trace import SpanContext
+from opentelemetry.trace import NoOpTracer, SpanContext
 from opentelemetry.trace.status import Status, StatusCode
 from opentelemetry.util import types
 from opentelemetry.util._decorator import _agnosticcontextmanager
@@ -1176,6 +1177,8 @@ def __init__(
             sampler = sampling._get_from_env_or_default()
         self.sampler = sampler
         self._span_limits = span_limits or SpanLimits()
+        disabled = environ.get(OTEL_SDK_DISABLED, "")
+        self._disabled = disabled.lower().strip() == "true"
         self._atexit_handler = None
 
         if shutdown_on_exit:
@@ -1191,6 +1194,9 @@ def get_tracer(
         instrumenting_library_version: typing.Optional[str] = None,
         schema_url: typing.Optional[str] = None,
     ) -> "trace_api.Tracer":
+        if self._disabled:
+            logger.warning("SDK is disabled.")
+            return NoOpTracer()
         if not instrumenting_module_name:  # Reject empty strings too.
             instrumenting_module_name = ""
             logger.error("get_tracer called with missing module name.")

opentelemetry-sdk/tests/logs/test_logs.py

@@ -15,12 +15,14 @@
 # pylint: disable=protected-access
 
 import unittest
-from unittest.mock import patch
+from unittest.mock import Mock, patch
 
 from opentelemetry.sdk._logs import LoggerProvider
 from opentelemetry.sdk._logs._internal import (
+    NoOpLogger,
     SynchronousMultiLogRecordProcessor,
 )
+from opentelemetry.sdk.environment_variables import OTEL_SDK_DISABLED
 from opentelemetry.sdk.resources import Resource
 
 
@@ -61,6 +63,11 @@ def test_get_logger(self):
             logger._instrumentation_scope.schema_url, "schema_url"
         )
 
+    @patch.dict("os.environ", {OTEL_SDK_DISABLED: "true"})
+    def test_get_logger_with_sdk_disabled(self):
+        logger = LoggerProvider().get_logger(Mock())
+        self.assertIsInstance(logger, NoOpLogger)
+
     @patch.object(Resource, "create")
     def test_logger_provider_init(self, resource_patch):
         logger_provider = LoggerProvider()

opentelemetry-sdk/tests/metrics/test_metrics.py

@@ -19,6 +19,7 @@
 from unittest.mock import MagicMock, Mock, patch
 
 from opentelemetry.metrics import NoOpMeter
+from opentelemetry.sdk.environment_variables import OTEL_SDK_DISABLED
 from opentelemetry.sdk.metrics import (
     Counter,
     Histogram,
@@ -465,6 +466,11 @@ def test_create_observable_up_down_counter(self):
         )
         self.assertEqual(observable_up_down_counter.name, "name")
 
+    @patch.dict("os.environ", {OTEL_SDK_DISABLED: "true"})
+    def test_get_meter_with_sdk_disabled(self):
+        meter_provider = MeterProvider()
+        self.assertIsInstance(meter_provider.get_meter(Mock()), NoOpMeter)
+
 
 class InMemoryMetricExporter(MetricExporter):
     def __init__(self):

opentelemetry-sdk/tests/trace/test_trace.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 # pylint: disable=too-many-lines
+# pylint: disable=no-member
 
 import shutil
 import subprocess
@@ -33,6 +34,7 @@
     OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT,
     OTEL_EVENT_ATTRIBUTE_COUNT_LIMIT,
     OTEL_LINK_ATTRIBUTE_COUNT_LIMIT,
+    OTEL_SDK_DISABLED,
     OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT,
     OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT,
     OTEL_SPAN_EVENT_COUNT_LIMIT,
@@ -162,6 +164,13 @@ def test_tracer_provider_accepts_concurrent_multi_span_processor(self):
             span_processor, tracer_provider._active_span_processor
         )
 
+    @mock.patch.dict("os.environ", {OTEL_SDK_DISABLED: "true"})
+    def test_get_tracer_with_sdk_disabled(self):
+        tracer_provider = trace.TracerProvider()
+        self.assertIsInstance(
+            tracer_provider.get_tracer(Mock()), trace_api.NoOpTracer
+        )
+
 
 class TestTracerSampling(unittest.TestCase):
     def tearDown(self):