opentelemetry-sdk: add ServiceInstanceIdResourceDetector for populating service.instance.id

[herin049]

Description

Creates a new ServiceInstanceIdResourceDetector for populating the service.instance.id resource attribute with a unique v4 UUID per the OTel spec:

Implementations, such as SDKs, are recommended to generate a random Version 1 or Version 4 RFC 4122 UUID, but are free to use an inherent unique ID as the source of this value if stability is desirable. In that case, the ID SHOULD be used as source of a UUID Version 5 and SHOULD use the following UUID as the namespace: 4d63009a-8d0f-11ee-aad7-4c796ed8e320.

In order to provide maximal flexibility, I have implemented these additions by creating an additional resource detector which must be enabled manually. If the SIG is ok with adding this resource attribute by default, I am open to instead adding this attribute directly in the existing OTELResourceDetector resource detector.

Fixes #5257

Type of change

Please delete options that are not relevant.

• 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?

uv run tox -e py314-test-opentelemetry-sdk

Does This PR Require a Contrib Repo Change?

• Yes. - Link to PR:
• No.

Checklist:

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

[aabmass]

🎉

[aabmass]

Let's give a short chance for anyone else to comment, otherwise please move to "Ready to Merge"

[Copilot]

Pull request overview

Adds an opt-in SDK resource detector to populate the OpenTelemetry service.instance.id resource attribute (via resource detector entry points), plus tests and a changelog entry.

Changes:

• Introduce ServiceInstanceIdResourceDetector that sets service.instance.id to a UUID.
• Register the detector under the opentelemetry_resource_detector entry point as service_instance (opt-in via OTEL_EXPERIMENTAL_RESOURCE_DETECTORS).
• Add unit tests covering UUID format and detector enablement, and add a changelog note.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
opentelemetry-sdk/src/opentelemetry/sdk/resources/__init__.py	Adds the new ServiceInstanceIdResourceDetector implementation.
opentelemetry-sdk/pyproject.toml	Registers the detector as an entry point (service_instance).
opentelemetry-sdk/tests/resources/test_resources.py	Adds tests for UUID validity and opt-in activation via env var.
.changelog/5259.added	Records the new feature in the changelog.

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[emdneto]

I'm fine with it, but I would prefer to be enabled by default in the Otel detector. Any thoughts?

[herin049]

Let's give a short chance for anyone else to comment, otherwise please move to "Ready to Merge"

@aabmass Good thing I looked over this again... I realized I made a very silly mistake 🤣

As implemented the service.instance.id will be different across different providers, which is certainly not correct. I also need to add logic so that service.instance.id changes upon process fork. Also, do we think that #5280 is going in the right direction, if so we can merge this in first and I can update the other PR have this new detector return True for is_process_sensitive()?

[herin049]

I'm fine with it, but I would prefer to be enabled by default in the Otel detector. Any thoughts?

@emdneto I can enable this by default, but I wanted to keep it separate from OTELResourceDetector assuming that the changes in #5280 get merged so that just this detector can be re-ran individually on process fork. Wdyt?

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.