How to use AutoConfigurationCustomizerProvider SPI with otel.experimental.config.file?

[Praytic]

I am using OTeL agent (version = 2.13.3) with my custom extension instrumentation which is basically one class that inherits AutoConfigurationCustomizerProvider. I connect it via OTEL_JAVAAGENT_EXTENSIONS environment variable and it is called correctly by ExtensionClassLoader. I also use opentelemetry-configuration by passing OTEL_EXPERIMENTAL_CONFIG_FILE env variable. When my metrics are exported my customizer is not called. I don't know how how my exporter is created because it's not in the classpath: io.opentelemetry.exporter.internal.grpc.GrpcExporter. Question is: How do I need to tweak config file or my customizer?

[jack-berg]

AutoConfigurationCustomizerProvider isn't called when OTEL_EXPERIMENTAL_CONFIG_FILE is set.

An alternative declarative config specific SPI called DeclarativeConfigurationCustomizerProvider is called instead.

Note that this provides the ability to customize the declarative config data model, but doesn't provide ability to customize exporters or other SDK plugin extension interfaces like SpanProcessor, Sampler, etc. See this comment for additional thoughts on this.

[jack-berg]

Closing as duplicate of #6576. Please add any additional details to that issue!