Initial cut at modelling service entities based on SIG discussions.

[jsuereth]

Fixes #2880

Changes

• Updates the service entity to consist of three components and describes each
• Adds a service specific markdown file for resource modelling
• Migrates existing attributes to appropriate entities in service.

Important

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Merge requirement checklist

• CONTRIBUTING.md guidelines followed.
• Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• Links to the prototypes or existing instrumentations (when adding or changing conventions)

[joaopgrassi]

I asked AI about how our model relates to k8s constructs. Here's the overview (which nicely aligns with our vision/goal/discussions so far)

OpenTelemetry Attribute	Kubernetes Construct	Description
service.name	Deployment or Service	Represents the logical name of the application or microservice. Typically aligns with a Kubernetes Deployment or Service name.
service.namespace	Namespace	Groups related services together. Aligns with Kubernetes namespaces for logical organization and isolation.
service.instance.id	Container ID	Uniquely identifies a specific instance of the service. Maps to the container runtime ID for the service's container.
service.version	Container Image Tag	Tracks the version of the service. Maps to the container image tag specified in the Deployment spec or Pod template.

[ymotongpoo]

I just took a glance for the update. I'll add more comments if I have any findings.

[joaopgrassi]

Looks great! Just a few, not blocking comments.

[joaopgrassi]

Suggested change

	aabcd-1231`"]
	http-server-1231`"]

[joaopgrassi]

Suggested change

	aabcd-1234`"]
	http-server-1234`"]

[trask]

is it ok that the Identity for service is only unique within another Entity (service.namespace)?

it wasn't clear to me from reading https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/entities/data-model.md#minimally-sufficient-identity

[jsuereth]

Yes. For any entity, we only guarantee global-uniqueness (i.e within some other entity).

E.g a process Identity is only unique within the context of some host.

That said, there's a balance to be had here of not requiring a bajillion entities on Resource to have a fully unique identity. Given, today, not all services have a namespace, I think it's reasonable to have it optional, and if you want to engage with namespace, you provide all of service.namespace, service + instance entities.