Add delcarative config support for specifying internal telemetry version

[jack-berg]

A variety of SDK components now follow the pattern for configuring internal telemetry:

Builder setInternalTelemetryVersion(InternalTelemetryVersion);
Builder setMeterProvider(Supplier<MeterProvider>);

For example,

opentelemetry-java/exporters/otlp/all/src/main/java/io/opentelemetry/exporter/otlp/http/trace/OtlpHttpSpanExporterBuilder.java

Lines 206 to 230 in 452506e

	/**
	* Sets the {@link MeterProvider} supplier to use to collect metrics related to export. If not
	* set, uses {@link GlobalOpenTelemetry#getMeterProvider()}.
	*
	* @since 1.32.0
	*/
	public OtlpHttpSpanExporterBuilder setMeterProvider(
	Supplier<MeterProvider> meterProviderSupplier) {
	requireNonNull(meterProviderSupplier, "meterProviderSupplier");
	delegate.setMeterProvider(meterProviderSupplier);
	return this;
	}
	/**
	* Sets the {@link InternalTelemetryVersion} defining which self-monitoring metrics this exporter
	* collects.
	*
	* @since 1.51.0
	*/
	public OtlpHttpSpanExporterBuilder setInternalTelemetryVersion(
	InternalTelemetryVersion schemaVersion) {
	requireNonNull(schemaVersion, "schemaVersion");
	delegate.setInternalTelemetryVersion(schemaVersion);
	return this;
	}

However, we lack controls for specifying the internal telemetry version using autoconfiguration mechanisms based on env vars and declarative config.

Let's add support to specify this in declarative config.

For example, I should be able to specify that I prefer InternalTelemetryVersion.LATEST with something like:

resource: ...
tracer_provider: ...
meter_provider: ...
logger_provider: ...
intstrumentation/development:
  java:
    sdk_internal:
      telemetry_version: latest

[jack-berg]

cc'ing people who have been interested in declarative config: @trask, @zeitlinger, @jaydeluca

And people who have been interested in internal telemetry: @anuraaga, @JonasKunz

[trask]

the internal in sdk_internal makes me think that I shouldn't use it

[jack-berg]

Maybe just sdk, or otel_sdk

[jkwatson]

how about otel_sdk.internal_telemetry_version ?

[zeitlinger]

Why is this in instrumentation at all - as the only sdk setting?

[jack-berg]

Its in a grey area. Its both instrumentation and an SDK setting. Its a bit easier to add to instrumentation than SDK because instrumentation is designed to have an open ended schema while SDK locks things down (for the most part with additionalProperties: false).