feat(config): add service resource detector support for declarative config by MikeGoldsmith · Pull Request #5003 · open-telemetry/opentelemetry-python

MikeGoldsmith · 2026-03-20T13:52:55Z

Description

Implements service resource detector support in create_resource() for the declarative configuration pipeline, as part of the ongoing work tracked in the following PRs:

What's included

Wires detection_development.detectors[].service via _run_detectors():
- Sets service.instance.id to a random UUID on every process start
- Reads OTEL_SERVICE_NAME env var for service.name if set (mirrors other SDK behaviour)
Explicit config attributes always take priority over detector-provided values
service.name=unknown_service default is set at the lowest priority so any detector or explicit attribute can override it
9 new tests covering instance ID uniqueness, env var reading, explicit attribute override, opt-in behaviour, and attribute filtering

Type of change

Bug fix (non-breaking change which fixes an issue)
New feature (non-breaking change which adds functionality)
Breaking change (fix or feature that would cause existing functionality to not work as expected)
This change requires a documentation update

How Has This Been Tested?

9 unit tests in tests/_configuration/test_resource.py
Includes explicit tests that the detector does not run when detection_development or detectors is absent

Does This PR Require a Contrib Repo Change?

Yes.
No.

Checklist:

Followed the style guidelines of this project
Changelogs have been updated
Unit tests have been added
Documentation has been updated

Assisted-by: Claude Sonnet 4.6

Implements create_resource() and create_propagator()/configure_propagator() for the declarative file configuration. Resource creation does not read OTEL_RESOURCE_ATTRIBUTES or run any detectors (matches Java/JS SDK behavior). Propagator configuration always calls set_global_textmap to override Python's default tracecontext+baggage, setting a noop CompositePropagator when no propagator is configured. Assisted-by: Claude Sonnet 4.6

Assisted-by: Claude Sonnet 4.6

- _resource.py: refactor _coerce_attribute_value to dispatch table to avoid too-many-return-statements; fix short variable names k/v -> attr_key/attr_val; fix return type of _sdk_default_attributes to dict[str, str] to satisfy pyright - _propagator.py: rename short variable names e -> exc, p -> propagator - test_resource.py: move imports to top level; split TestCreateResource (25 methods) into three focused classes to satisfy too-many-public-methods - test_propagator.py: add pylint disable for protected-access Assisted-by: Claude Sonnet 4.6

- replace _sdk_default_attributes() with _DEFAULT_RESOURCE from resources module - move _coerce_bool into dispatch tables for both scalar and array bool types, fixing a bug where bool_array with string values like "false" would coerce incorrectly via plain bool() (non-empty string -> True) - add test for bool_array with string values to cover the bug Assisted-by: Claude Sonnet 4.6

… into mike/config-resource-propagator

…erge - collapse _SCALAR_COERCIONS and _ARRAY_COERCIONS into a single _COERCIONS dict using an _array() factory, reducing _coerce_attribute_value to two lines - process attributes_list before attributes so explicit attributes naturally overwrite list entries without needing an explicit guard Assisted-by: Claude Sonnet 4.6

Assisted-by: Claude Sonnet 4.6

…e-propagator

Adds _run_detectors() stub and _filter_attributes() to create_resource(), providing the shared scaffolding for detector PRs to build on. Detectors are opt-in: nothing runs unless explicitly listed under detection_development.detectors in the config. The include/exclude attribute filter mirrors other SDK behaviour. Assisted-by: Claude Sonnet 4.6

Merges service.name=unknown_service into base before running detectors, so detectors (e.g. service) can override it. Previously it was added to config_attrs and merged last, which would have silently overridden any detector-provided service.name. Assisted-by: Claude Sonnet 4.6

Assisted-by: Claude Sonnet 4.6

Adds service detector support to _run_detectors(): sets a random UUID for service.instance.id and reads OTEL_SERVICE_NAME for service.name if set. Explicit config attributes still take priority (merged last). Assisted-by: Claude Sonnet 4.6

Assisted-by: Claude Sonnet 4.6

…Detector Assisted-by: Claude Sonnet 4.6

Assisted-by: Claude Sonnet 4.6

aabmass · 2026-04-03T19:43:25Z

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

    """
+    if detector_config.service is not None:
+        attrs: dict[str, object] = {
+            SERVICE_INSTANCE_ID: str(uuid.uuid4()),


Sets service.instance.id to a random UUID on every process start

I can't remember if this is in the spec already. Feel free to resolve if it is or doesn't need more discussion

Yes, this is in the spec. The semantic conventions for service.instance.id specify it should be a unique identifier for each instance, with a UUID being the recommended value. The opentelemetry-configuration schema also describes the service detector as populating service.instance.id.

aabmass · 2026-04-03T19:48:02Z

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

+        attrs: dict[str, object] = {
+            SERVICE_INSTANCE_ID: str(uuid.uuid4()),
+        }
+        service_name = os.environ.get(OTEL_SERVICE_NAME)


How does this work along with the OTELResourceDetector?

opentelemetry-python/opentelemetry-sdk/src/opentelemetry/sdk/resources/__init__.py

Line 360 in e301732

service_name = environ.get(OTEL_SERVICE_NAME)

create_resource intentionally does not invoke OTELResourceDetector and does not read OTEL_RESOURCE_ATTRIBUTES — Declarative config's WYSIWYG semantics mean env vars don't bleed in unless explicitly configured. The one env var the service detector does read is OTEL_SERVICE_NAME, which is intentional per the opentelemetry-configuration schema ("populates service.name based on the OTEL_SERVICE_NAME environment variable"). Java's implementation does the same. JS diverges by only setting service.instance.id and leaving OTEL_SERVICE_NAME to a separate env detector, which may be a bug there (I'm also helping out there so can fix it there too).

Assisted-by: Claude Sonnet 4.6

MikeGoldsmith added 11 commits March 13, 2026 13:04

update changelog with PR number

8232012

Assisted-by: Claude Sonnet 4.6

fix linter

8232d48

Merge branch 'main' of github.com:open-telemetry/opentelemetry-python…

6ed3425

… into mike/config-resource-propagator

use Callable type annotation on _array helper

8ba91d8

Assisted-by: Claude Sonnet 4.6

Merge remote-tracking branch 'upstream/main' into mike/config-resourc…

516aecc

…e-propagator

MikeGoldsmith force-pushed the mike/config-resource-detector-service branch from b62c43c to a2b7031 Compare March 20, 2026 14:26

MikeGoldsmith added a commit to MikeGoldsmith/opentelemetry-python that referenced this pull request Mar 20, 2026

add changelog entry for service resource detector (open-telemetry#5003)

6fd726b

Assisted-by: Claude Sonnet 4.6

MikeGoldsmith added 3 commits March 20, 2026 18:22

remove unused logging import from _propagator.py

7f51034

Assisted-by: Claude Sonnet 4.6

add changelog entry for service resource detector (open-telemetry#5003)

2306b93

Assisted-by: Claude Sonnet 4.6

MikeGoldsmith force-pushed the mike/config-resource-detector-service branch from 6fd726b to 2306b93 Compare March 20, 2026 19:46

merge upstream/main and fix pylint no-self-use in TestServiceResource…

72c9db8

…Detector Assisted-by: Claude Sonnet 4.6

MikeGoldsmith marked this pull request as ready for review March 29, 2026 16:33

MikeGoldsmith requested a review from a team as a code owner March 29, 2026 16:33

tammy-baylis-swi approved these changes Mar 30, 2026

View reviewed changes

MikeGoldsmith mentioned this pull request Mar 31, 2026

ci: add GHA to add PRs to project board when marked ready for review #5026

Open

1 task

merge upstream/main

4de33e5

Assisted-by: Claude Sonnet 4.6

github-project-automation bot added this to Python PR digest Apr 1, 2026

MikeGoldsmith moved this to Approved PRs in Python PR digest Apr 1, 2026

Merge branch 'main' into mike/config-resource-detector-service

9e41d24

aabmass reviewed Apr 3, 2026

View reviewed changes

merge upstream/main

f63e2d9

Assisted-by: Claude Sonnet 4.6

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feat(config): add service resource detector support for declarative config#5003

feat(config): add service resource detector support for declarative config#5003
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Description

What's included

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How Has This Been Tested?

Does This PR Require a Contrib Repo Change?

Checklist:

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MikeGoldsmith commented Mar 20, 2026 •

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