Schema for the instrumentation section of declarative config (maybe including vendor specific)

[zeitlinger]

Is your feature request related to a problem? Please describe.

Based on #14014 (comment)

Describe the solution you'd like

Describe alternatives you've considered

No response

Additional context

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[jack-berg]

• We need some way to express the schema of one (or more) instrumentation libraries
  • Naively, can hand write POJO classes annotated with jackson's @JsonProperty annotations
  • A better solution would be to integrate with @jaydeluca's metadata tooling, such that:
    • The schema of each instrumentation library's config is represented in YAML
    • Tooling can generate POJO classes annotated with jackson's @JsonProperty
    • Can integrate with IDE's to provide autocomplete support when authoring declarative config YAML
• With POJO classes annotated with jackson's @JsonProperty annotation, can offer a centralized DeclarativeConfiguration.translate method which accepts a DeclarativeConfigProperties instance (i.e. the declarative config equivalent of a YAML node), and a reference to a POJO class to translate it to, and would return an instance of that POJO

Workflow would be something like:

class FooInstrumentationSchema {
  @JsonProperty("bar")
  private String bar;
  ...
}

FooInstrumentationSchema fooInstrumentationSchema = DeclarativeConfiguration.translate(DeclarativeConfigProperties, TypeReference<FooInstrumentationSchema>)

// Initialize instrumentation accordingly

And a user would then configure the instrumentation module as follows:

instrumentation/development:
  java:
    foo:
      bar: baz