Remove importlib-metadata dependency (open-telemetry#5203)

aabmass · herin049 · xrmx · web-flow · commit 1a33c692f024 · 2026-05-14T15:31:10.000Z
* Remove importlib-metadata dependency Remove the third-party importlib-metadata dependency in favor of the standard library's importlib.metadata, which is stable and available natively since Python >= 3.10. Implements a unified, branchless caching wrapper in `opentelemetry-api` that: - Bypasses standard `entry_points()` version-specific return type differences (SelectableGroups vs EntryPoints) by building a flat `EntryPoints` sequence directly from the low-level `distributions()` API. - Caches all resolved entry points in-memory on the first call to avoid severe startup performance degradation caused by repeated filesystem scans in standard library `importlib.metadata` (resulting in a 37x speedup on subsequent lookups and a 2x faster cold start). - Cleans up obsolete `importlib-metadata` and `zipp` requirements across 19 test and documentation configurations. Assisted-by: Gemini * Refactor importlib.metadata caching wrapper to address PR comments - Leverage stdlib `entry_points()` directly instead of the custom `distributions()` loop, ensuring standard library's `sys.path` shadowing resolution (uniqueness filtering) is perfectly preserved. - Map Python 3.10/3.11 `SelectableGroups` (dict-like object) to `EntryPoints` (sequence) using a compatibility helper `_as_entry_points`. - Cache the result of the no-argument stdlib `entry_points()` call via `@cache` to eliminate redundant disk-scanning on repeated lookups. - Add a compatibility unit test for `_as_entry_points` with dict-like input. Assisted-by: Gemini * Apply suggestion from @herin049 Co-authored-by: Lukas Hering <40302054+herin049@users.noreply.github.com> * Add Sphinx RST module docstring to _importlib_metadata.py Assisted-by: Gemini * Undo rename of _original_entry_points_cached and document test behavior - Revert the caching function name back to _original_entry_points_cached to avoid unnecessary churn. - Add a docstring to test_as_entry_points_selectable_groups_compat explaining the normalization of Python 3.10 SelectableGroups vs 3.11+. Assisted-by: Gemini --------- Co-authored-by: Lukas Hering <40302054+herin049@users.noreply.github.com> Co-authored-by: Riccardo Magliocchetti <riccardo.magliocchetti@gmail.com>
diff --git a/.changelog/3234.removed b/.changelog/3234.removed
@@ -0,0 +1 @@
+`opentelemetry-api`: remove third-party importlib-metadata in favor of standard library since Python >= 3.10 is now required
diff --git a/codegen/opentelemetry-codegen-json/test-requirements.txt b/codegen/opentelemetry-codegen-json/test-requirements.txt
@@ -1,12 +1,10 @@
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.5.0
 protobuf==6.31.1
 pytest==7.4.4
 tomli==2.0.1
 typing_extensions==4.12.0
-zipp==3.19.2
 grpcio==1.78.0
 grpcio-tools==1.78.0
 -e codegen/opentelemetry-codegen-json
diff --git a/docs/getting_started/tests/requirements.txt b/docs/getting_started/tests/requirements.txt
@@ -5,7 +5,6 @@ charset-normalizer==2.0.12
 click==8.1.7
 Flask==2.3.3
 idna==3.7
-importlib-metadata==6.8.0
 iniconfig==2.0.0
 itsdangerous==2.1.2
 Jinja2==3.1.5
@@ -20,7 +19,6 @@ typing_extensions==4.12.0
 urllib3==1.26.19
 Werkzeug==3.0.6
 wrapt==1.15.0
-zipp==3.19.2
 -e opentelemetry-semantic-conventions
 -e opentelemetry-proto
 -e exporter/opentelemetry-exporter-otlp-proto-common
diff --git a/exporter/opentelemetry-exporter-opencensus/test-requirements.txt b/exporter/opentelemetry-exporter-opencensus/test-requirements.txt
@@ -1,6 +1,5 @@
 asgiref==3.7.2
 grpcio==1.75.1
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 opencensus-proto==0.1.0
 packaging==24.0
@@ -11,7 +10,6 @@ pytest==7.4.4
 tomli==2.0.1
 typing_extensions==4.12.0
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e opentelemetry-sdk
 -e tests/opentelemetry-test-utils
diff --git a/exporter/opentelemetry-exporter-otlp-json-common/test-requirements.txt b/exporter/opentelemetry-exporter-otlp-json-common/test-requirements.txt
@@ -1,5 +1,4 @@
 asgiref==3.7.2
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -9,7 +8,6 @@ pytest==7.4.4
 tomli==2.0.1
 typing_extensions==4.12.0
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e opentelemetry-sdk
 -e opentelemetry-semantic-conventions
diff --git a/exporter/opentelemetry-exporter-otlp-proto-common/test-requirements.txt b/exporter/opentelemetry-exporter-otlp-proto-common/test-requirements.txt
@@ -1,5 +1,4 @@
 asgiref==3.7.2
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -9,7 +8,6 @@ pytest==7.4.4
 tomli==2.0.1
 typing_extensions==4.12.0
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e opentelemetry-sdk
 -e opentelemetry-semantic-conventions
diff --git a/exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.latest.txt b/exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.latest.txt
@@ -33,6 +33,10 @@ asgiref==3.7.2
     # via
     #   -c dev-requirements.txt
     #   opentelemetry-test-utils
+certifi==2026.4.22
+    # via requests
+charset-normalizer==3.4.7
+    # via requests
 colorama==0.4.6
     # via
     #   -r exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.in
@@ -43,8 +47,8 @@ googleapis-common-protos==1.74.0
     # via opentelemetry-exporter-otlp-proto-grpc
 grpcio==1.80.0
     # via opentelemetry-exporter-otlp-proto-grpc
-importlib-metadata==8.7.1
-    # via opentelemetry-api
+idna==3.14
+    # via requests
 iniconfig==2.3.0
     # via
     #   -r exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.in
@@ -66,6 +70,10 @@ pytest==7.4.4
     # via
     #   -c dev-requirements.txt
     #   -r exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.in
+requests==2.32.3
+    # via
+    #   -c dev-requirements.txt
+    #   opentelemetry-test-utils
 tomli==2.4.1 ; python_full_version < '3.11'
     # via pytest
 typing-extensions==4.15.0
@@ -77,5 +85,5 @@ typing-extensions==4.15.0
     #   opentelemetry-exporter-otlp-proto-grpc
     #   opentelemetry-sdk
     #   opentelemetry-semantic-conventions
-zipp==3.23.0
-    # via importlib-metadata
+urllib3==2.7.0
+    # via requests
diff --git a/exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.oldest.txt b/exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.oldest.txt
@@ -33,6 +33,10 @@ asgiref==3.7.2
     # via
     #   -c dev-requirements.txt
     #   opentelemetry-test-utils
+certifi==2017.4.17
+    # via requests
+charset-normalizer==2.0.0
+    # via requests
 colorama==0.4.6
     # via
     #   -r exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.in
@@ -47,8 +51,8 @@ grpcio==1.66.2 ; python_full_version == '3.13.*'
     # via opentelemetry-exporter-otlp-proto-grpc
 grpcio==1.75.1 ; python_full_version >= '3.14'
     # via opentelemetry-exporter-otlp-proto-grpc
-importlib-metadata==6.0.0
-    # via opentelemetry-api
+idna==2.5
+    # via requests
 iniconfig==2.0.0
     # via
     #   -r exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.in
@@ -70,6 +74,10 @@ pytest==7.4.4
     # via
     #   -c dev-requirements.txt
     #   -r exporter/opentelemetry-exporter-otlp-proto-grpc/test-requirements.in
+requests==2.32.3
+    # via
+    #   -c dev-requirements.txt
+    #   opentelemetry-test-utils
 tomli==1.0.0 ; python_full_version < '3.11'
     # via pytest
 typing-extensions==4.6.0 ; python_full_version < '3.14'
@@ -86,5 +94,5 @@ typing-extensions==4.12.0 ; python_full_version >= '3.14'
     #   opentelemetry-exporter-otlp-proto-grpc
     #   opentelemetry-sdk
     #   opentelemetry-semantic-conventions
-zipp==0.5.0
-    # via importlib-metadata
+urllib3==1.21.1
+    # via requests
diff --git a/exporter/opentelemetry-exporter-otlp-proto-http/test-requirements.txt b/exporter/opentelemetry-exporter-otlp-proto-http/test-requirements.txt
@@ -3,7 +3,6 @@ certifi==2024.7.4
 charset-normalizer==3.3.2
 googleapis-common-protos==1.70.0
 idna==3.7
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -17,7 +16,6 @@ tomli==2.0.1
 typing_extensions==4.12.0
 urllib3==2.2.2
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e tests/opentelemetry-test-utils
 -e exporter/opentelemetry-exporter-otlp-proto-common
diff --git a/exporter/opentelemetry-exporter-otlp/test-requirements.txt b/exporter/opentelemetry-exporter-otlp/test-requirements.txt
@@ -1,5 +1,4 @@
 asgiref==3.7.2
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -8,7 +7,6 @@ pytest==7.4.4
 tomli==2.0.1
 typing_extensions==4.12.0
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e tests/opentelemetry-test-utils
 -e exporter/opentelemetry-exporter-otlp-proto-common
diff --git a/exporter/opentelemetry-exporter-prometheus/test-requirements.txt b/exporter/opentelemetry-exporter-prometheus/test-requirements.txt
@@ -1,5 +1,4 @@
 asgiref==3.7.2
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -9,7 +8,6 @@ pytest==7.4.4
 tomli==2.0.1
 typing_extensions==4.10.0
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e opentelemetry-sdk
 -e tests/opentelemetry-test-utils
diff --git a/exporter/opentelemetry-exporter-zipkin-json/test-requirements.txt b/exporter/opentelemetry-exporter-zipkin-json/test-requirements.txt
@@ -2,7 +2,6 @@ asgiref==3.7.2
 certifi==2024.7.4
 charset-normalizer==3.3.2
 idna==3.7
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -13,7 +12,6 @@ tomli==2.0.1
 typing_extensions==4.10.0
 urllib3==2.2.2
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e opentelemetry-sdk
 -e opentelemetry-semantic-conventions
diff --git a/exporter/opentelemetry-exporter-zipkin-proto-http/test-requirements.txt b/exporter/opentelemetry-exporter-zipkin-proto-http/test-requirements.txt
@@ -2,7 +2,6 @@ asgiref==3.7.2
 certifi==2024.7.4
 charset-normalizer==3.3.2
 idna==3.7
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -14,7 +13,6 @@ tomli==2.0.1
 typing_extensions==4.10.0
 urllib3==2.2.2
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e exporter/opentelemetry-exporter-zipkin-json
 -e opentelemetry-sdk
diff --git a/exporter/opentelemetry-exporter-zipkin/test-requirements.txt b/exporter/opentelemetry-exporter-zipkin/test-requirements.txt
@@ -1,5 +1,4 @@
 asgiref==3.7.2
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -8,7 +7,6 @@ pytest==7.4.4
 tomli==2.0.1
 typing_extensions==4.10.0
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e exporter/opentelemetry-exporter-zipkin-json
 -e exporter/opentelemetry-exporter-zipkin-proto-http
diff --git a/opentelemetry-api/pyproject.toml b/opentelemetry-api/pyproject.toml
@@ -26,9 +26,6 @@ classifiers = [
 ]
 dependencies = [
     "typing-extensions >= 4.5.0",
-    # FIXME This should be able to be removed after 3.12 is released if there is a reliable API
-    # in importlib.metadata.
-    "importlib-metadata >= 6.0, < 8.8.0",
 ]
 dynamic = [
     "version",
diff --git a/opentelemetry-api/src/opentelemetry/util/_importlib_metadata.py b/opentelemetry-api/src/opentelemetry/util/_importlib_metadata.py
@@ -1,12 +1,18 @@
 # Copyright The OpenTelemetry Authors
 # SPDX-License-Identifier: Apache-2.0
 
-from functools import cache
+"""
+Caching and compatibility wrapper for standard library ``importlib.metadata``.
+
+This module caches ``entry_points()`` to avoid reloading entry points from disk on every call.
+It also normalizes minor differences across python versions 3.10+. References to issues:
 
-# FIXME: Use importlib.metadata (not importlib_metadata)
-# when support for 3.11 is dropped if the rest of
-# the supported versions at that time have the same API.
-from importlib_metadata import (  # type: ignore
+- https://github.com/open-telemetry/opentelemetry-python/pull/4735
+- https://github.com/open-telemetry/opentelemetry-python/pull/5203
+"""
+
+from functools import cache
+from importlib.metadata import (
     Distribution,
     EntryPoint,
     EntryPoints,
@@ -15,20 +21,23 @@
     requires,
     version,
 )
-from importlib_metadata import (
-    entry_points as original_entry_points,
-)
+from importlib.metadata import entry_points as original_entry_points
+from typing import Any
+
+
+def _as_entry_points(eps: Any) -> EntryPoints:
+    if isinstance(eps, EntryPoints):
+        return eps
+    # Handle Python 3.10 SelectableGroups (dict-like)
+    return EntryPoints(ep for group_eps in eps.values() for ep in group_eps)
 
 
 @cache
-def _original_entry_points_cached():
-    return original_entry_points()
+def _original_entry_points_cached() -> EntryPoints:
+    return _as_entry_points(original_entry_points())
 
 
 def entry_points(**params) -> EntryPoints:
-    """Replacement for importlib_metadata.entry_points that caches getting all the entry points.
-
-    That part can be very slow, and OTel uses this function many times."""
     return _original_entry_points_cached().select(**params)
 
 
diff --git a/opentelemetry-api/test-requirements.txt b/opentelemetry-api/test-requirements.txt
@@ -1,5 +1,4 @@
 asgiref==3.7.2
-importlib-metadata==8.7.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
diff --git a/opentelemetry-api/tests/util/test__importlib_metadata.py b/opentelemetry-api/tests/util/test__importlib_metadata.py
@@ -7,6 +7,7 @@
 from opentelemetry.util._importlib_metadata import (
     EntryPoint,
     EntryPoints,
+    _as_entry_points,
     version,
 )
 from opentelemetry.util._importlib_metadata import (
@@ -100,3 +101,19 @@ def test_uniform_behavior(self):
         self.assertEqual(len(entry_points), 0)
 
         self.assertIsInstance(version("opentelemetry-api"), str)
+
+    def test_as_entry_points_selectable_groups_compat(self):
+        """Test that _as_entry_points correctly normalizes dict-like SelectableGroups
+        (returned by importlib.metadata.entry_points() in Python 3.10) into EntryPoints.
+
+        On Python 3.11+, entry_points() returns EntryPoints directly, which is
+        handled by the fast-path in _as_entry_points.
+        """
+        ep1 = EntryPoint(name="foo", value="bar:baz", group="gp")
+        ep2 = EntryPoint(name="foo2", value="bar2:baz2", group="gp")
+        selectable_groups = {"gp": [ep1, ep2]}
+
+        normalized = _as_entry_points(selectable_groups)
+        self.assertIsInstance(normalized, EntryPoints)
+        self.assertEqual(len(normalized), 2)
+        self.assertEqual(list(normalized), [ep1, ep2])
diff --git a/opentelemetry-sdk/test-requirements.txt b/opentelemetry-sdk/test-requirements.txt
@@ -1,6 +1,5 @@
 asgiref==3.7.2
 flaky==3.7.0
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
diff --git a/opentelemetry-semantic-conventions/test-requirements.txt b/opentelemetry-semantic-conventions/test-requirements.txt
@@ -1,5 +1,4 @@
 asgiref==3.7.2
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
diff --git a/propagator/opentelemetry-propagator-b3/test-requirements.txt b/propagator/opentelemetry-propagator-b3/test-requirements.txt
@@ -1,5 +1,4 @@
 asgiref==3.7.2
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -8,7 +7,6 @@ pytest==7.4.4
 tomli==2.0.1
 typing_extensions==4.10.0
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e opentelemetry-sdk
 -e opentelemetry-semantic-conventions
diff --git a/propagator/opentelemetry-propagator-jaeger/test-requirements.txt b/propagator/opentelemetry-propagator-jaeger/test-requirements.txt
@@ -1,5 +1,4 @@
 asgiref==3.7.2
-importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.6.0
@@ -8,7 +7,6 @@ pytest==7.4.4
 tomli==2.0.1
 typing_extensions==4.10.0
 wrapt==1.16.0
-zipp==3.19.2
 -e opentelemetry-api
 -e opentelemetry-sdk
 -e opentelemetry-semantic-conventions
diff --git a/shim/opentelemetry-opencensus-shim/test-requirements.txt b/shim/opentelemetry-opencensus-shim/test-requirements.txt
diff --git a/shim/opentelemetry-opentracing-shim/test-requirements.txt b/shim/opentelemetry-opentracing-shim/test-requirements.txt
diff --git a/tests/opentelemetry-test-utils/test-requirements.txt b/tests/opentelemetry-test-utils/test-requirements.txt
diff --git a/uv.lock b/uv.lock

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+`opentelemetry-api`: remove third-party importlib-metadata in favor of standard library since Python >= 3.10 is now required