Setting OTEL_EXPORTER_OTLP_HEADERS when using SpringBoot starter fails with ConverterNotFoundException

[c-north-8]

Describe the bug

Using spring boot starter v2.0.0, which introduced an improvement for using the OTEL_EXPORTER_OTLP_HEADERS property, I get the following error message.

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APPLICATION FAILED TO START

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Description:

Failed to bind properties under 'otel.exporter.otlp.headers' to java.util.Map<java.lang.String, java.lang.String>:

Property: otel.exporter.otlp.headers
Value: "api-key=12345"
Origin: System Environment Property "OTEL_EXPORTER_OTLP_HEADERS"
Reason: org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [java.lang.String] to type [java.util.Map<java.lang.String, java.lang.String>]

Action:

Update your application's configuration

Steps to reproduce

1. Add opentelemetry-spring-boot-starter to Maven dependency (v2.0.0) in app
2. Set the following environment variables
   • OTEL_EXPORTER_OTLP_HEADERS=api-key=123
3. Run the app and see error message

Expected behavior

Setting the environment variable as described by the documentation would result in an api-key property being added to the headers Map for the OTLP exporter.

Actual behavior

Application fails to start with a ConverterNotFoundException

Javaagent or library instrumentation version

2.0.0_alpha

Environment

Spring Boot 3.2.1, Java 17

Additional context

When setting the headers via application.properties (e.g. otel.exporter.otlp.headers.api-key=12345), the application works as intended. It is only when trying to set via environment variables that the header is not respected or read.

[zeitlinger]

I can't reproduce the issue using the spring demo.

Please compare this to your setup and point out the difference - or create a draft PR against the demo for illustration.

[github-actions]

This has been automatically marked as stale because it has been marked as needing author feedback and has not had any activity for 7 days. It will be closed automatically if there is no response from the author within 7 additional days from this comment.

[zeitlinger]

May be a duplicate of #10344

[zeitlinger]

I'm pretty sure it's a duplicate.