Add oracle_cloud.realm vendor attribute

[geekdave]

Fixes #3121

Changes

Add oracle_cloud.realm vendor-specific attribute for Oracle Cloud Infrastructure (OCI) realm identifier.

Note

This will be used in the already-created Oracle Cloud resource detection processor, part of the collector-contrib project. See: open-telemetry/opentelemetry-collector-contrib#44408

I went back and forth about whether this realm attribute should be placed at:

a) the root of the vendor-prefixed hierarchy such as oracle_cloud.realm or
b) in service-specific properties like oracle_cloud.oracle_cloud_oke.realm and oracle_cloud.oracle_cloud_compute.realm

I asked about this in #otel-semantic-conventions and got this feedback from @thompson-tomo :

In the case here I lean towards having a single attribute based on the assumption that a realm is more like cloud.region hence a signal would only be describing a single realm

I am open to more feedback on this. But realm is a concept that applies to nearly all OCI services, so I think it makes sense to place it at the root.

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]
• [N/A] Links to the prototypes or existing instrumentations (when adding or changing conventions)

[github-actions]

This PR contains changes to area(s) that do not have an active SIG/project and will be auto-closed:

• oracle-cloud

Such changes may be rejected or put on hold until a new SIG/project is established.

Please refer to the Semantic Convention Areas
document to see the current active SIGs and also to learn how to kick start a new one.

[geekdave]

cc @dashpole . Not sure what to do about the above error. Do we need to start a new SIG/project?

[dashpole]

@jsuereth I Don't see a SIG/project associated with most cloud providers. How can we add oracle-cloud? Do we need a new SIG?

[geekdave]

Paused, pending creation of oracle_cloud approvers group. Proposal: open-telemetry/community#3185

[thompson-tomo]

@geekdave thoughts on having the attribute named oracle_cloud.realm.id/key that way we could at a later date add additional oracle_cloud.realm.* attributes if the need arises.

Also it might be a good idea to associate the new attribute with an entity. Based on https://opentelemetry.io/docs/specs/semconv/how-to-write-conventions/resource-and-entities/#when-to-define-an-is-a-relationship-vs-extending-descriptive-attributes my suggestion would be to extend the existing cloud entity with the additional attribute as i don't see us generating metrics specific to an Oracle cloud location which doesn't apply to all cloud locations.

For this cloud entity I would see the identifying attributes being cloud.availability_zone + cloud.provider but that would likely be separate pr to define those roles.

[github-actions]

This PR has been labeled as stale due to lack of activity. It will be automatically closed if there is no further activity over the next 7 days.

[trask]

Closing and re-opening to see if it picks up new CODEOWNERS

[geekdave]

@thompson-tomo thanks for the suggestion! I attended the semconf SIG meeting via Zoom this morning and we discussed this topic. The consensus was that it's OK to leave realm as a simple attribute that represents the entire identity, similar to how availability_zone works now.