Remove prefix in yaml, add policy check to block future usages (and minor cleanups)

[lmolkova]

Changes

Related to #1292 - this PR does not block anyone from using prefix, only changes the current pattern.

• Changes all attribute definitions to use fully qualified attribute names and removes all prefixes
• Add rego policy to detect and fail when prefix is used.
• Removes (ignored) allow_custom_values on enums

Merge requirement checklist

• [x] CONTRIBUTING.md guidelines followed.
• [x] 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]
• [x] schema-next.yaml updated with changes to existing conventions.

[trisch-me]

prefix is used in embed functionality, i.e. if I'm embedding geo.lat into client the resolved attribute should have full name as client.geo.lat

[lmolkova]

@trisch-me great point. This would be a blocker to #1292 and tooling changes https://github.com/open-telemetry/weaver/issues/263.

I still want to proceed with this PR since it does not stop someone from using prefix now (when necessary) or tooling from introducing any changes that can still leverage the prefix.

[trisch-me]

actually it does break it - as soon as prefix will be added because someone needs it the resolved registry with current weaver will double the prefix, so it will be prefix.prefix.attribute. I think this PR should go along together with weaver PR to NOT include prefix into resolved name anymore

[lmolkova]

actually it does break it - as soon as prefix will be added because someone needs it the resolved registry with current weaver will double the prefix, so it will be prefix.prefix.attribute.

whoever adds it, would remove it from the attribute id to not break things - nothing depends on prefix location today.

[trisch-me]

whoever adds it, would remove it from the attribute id to not break things

but then it is inconsistent. If we have decided to be explicit and provide prefix always in the id we need to update instrumentation as well so in case prefix would be there it will not break. Therefore I propose to merge this PR only together with/after weaver PR.

If you want I can create a PR in weaver which does this job but I'm against merging this PR until tooling is ready.

[lmolkova]

but then it is inconsistent. If we have decided to be explicit and provide prefix always in the id we need to update instrumentation as well so in case prefix would be there it will not break.

it's already inconsistent. Check out deprecated attributes in the registry. All the tooling is agnostic to where the prefix is today. Instrumentations use fully qualified name (prefix + id) since that's how tooling resolves name - the id/prefix is in most cases are not even visible beyond weaver/build-tools.

I'm ok waiting for the tooling changes. I'm trying to explain that this PR does not change status quo.

[trisch-me]

Instrumentations use fully qualified name (prefix + id) this is where I see things are breaking. Because if someone adds a prefix back because it's needed for other functionality, all id's in that group will be wrong or should be updated again to not have prefix in them. So better to remove dependency on prefix for name resolution

[lmolkova]

discussed at the tooling wg call

• it's important to make a consistent choice and, if the decision is to stop using prefix, to stop using it everywhere.
• we can prohibit using prefix with rego policy - added one in this PR
• schema and tooling updates can happen after migration to weaver.

@trisch-me I want to double-check if you're ok with it. The embed design does not seem depend on the prefix anymore (#1264), but If it we end up needing it, we can always roll back this PR (partially or fully) - this is another benefit of enforcing it in the policy for now and not (yet) in the tooling.