core-logs: add LogRecordBuilder

[iRevive]

The spec: https://opentelemetry.io/docs/specs/otel/logs/api/#emit-a-logrecord

[iRevive]

That's the unfortunate part.

The spec explicitly says the API must accept the Context:

The Context associated with the LogRecord. When implicit Context is supported, then this parameter SHOULD be optional and if unspecified then MUST use current Context. When only explicit Context is supported, this parameter SHOULD be required.

[iRevive]

@NthPortal could you please take a look at it once you have a moment?

[NthPortal]

I'm so sorry for taking so long.

I'm a bit concerned that this part of the spec is listed as having the "Development" status, but this code does seem to follow the spec.

my only concern is that it seems to be missing a way to add an EventName

[iRevive]

I'm a bit concerned that this part of the spec is listed as having the "Development" status, but this code does seem to follow the spec.

That's a fair concern. If I understand correctly, only the attribute-conversion API is under development.

The API SHOULD provide functionality for users to convert Standard Attributes so they can be used, or directly accept them, in the log signal. This allows the reuse of Standard Attributes across signals.

The log record builder API accepts logs attributes, which is basically Map[String, AnyValue], while we use standard attributes Map[String, Attribute[_]].

otel-java uses standard attributes in the LogRecordBuilder API as well: https://github.com/open-telemetry/opentelemetry-java/blob/v1.52.0/api/all/src/main/java/io/opentelemetry/api/logs/LogRecordBuilder.java#L98-L105.

And there is a problem. Even if we define LogsAttributes = Map[String, AnyValue], we cannot translate them directly into the standard attributes, and as a result, we cannot reliably use otel-java as a backend.

I think at this point we should follow oteljava route.

my only concern is that it seems to be missing a way to add an EventName

Hm, indeed. Let me add this one.

[iRevive]

Done. I added the withEventName method