add support for missing list properties in spring starter

[zeitlinger]

Spring needs special handling of lists and maps

• yaml lists only work if you create a @ConfigurationProperties object
• strings and other primitives don't need @ConfigurationProperties - you can simply get them from the environment

So what was actually missing:

• We were missing some lists, so users were unable to use the property in application.yaml.
• Some metadata were also missing - and some were documented to be working even though they were not https://github.com/open-telemetry/opentelemetry-java-instrumentation/pull/12434/files#diff-b1a332ea15f7cba0ef03ccf907c6c12f8f0b0f6291c59d0dd6e2b975729c93d2
• One property was not working correctly, because the spring properties are not processed by properties customizers. The solution is to re-apply this customizer: https://github.com/open-telemetry/opentelemetry-java-instrumentation/pull/12434/files#diff-64cab1cece1eb9d2bec371ffcd8317175f023b18dbc5861d53aca0878c7fee69R86-R104

[zeitlinger]

@jeanbisutti please take a look

[jeanbisutti]

Does this PR mean that the list properties were not properly managed by the OTel starter?

SpringConfigProperties has already a getList implementation:

opentelemetry-java-instrumentation/instrumentation/spring/spring-boot-autoconfigure/src/main/java/io/opentelemetry/instrumentation/spring/autoconfigure/internal/properties/SpringConfigProperties.java

Line 113 in 8a10097

public List<String> getList(String name) {

What are the limitations of the current implementation?

[zeitlinger]

What are the limitations of the current implementation?

not all relevant list properties were included - and all list properties have to be supported specifically due to how spring treats lists

[jeanbisutti]

not all relevant list properties were included

This one seems to be new:

https://github.com/zeitlinger/opentelemetry-java-instrumentation/blob/3952fcfd785f7eb9cc8ef4e75fd59f99059a41fd/instrumentation/spring/spring-boot-autoconfigure/src/main/resources/META-INF/additional-spring-configuration-metadata.json#L80

and all list properties have to be supported specifically due to how spring treats lists

Could you please elaborate this and the new properties in the PR description? It would help to review the PR and the users understand what is new.

[zeitlinger]

Could you please elaborate this and the new properties in the PR description? It would help to review the PR and the users understand what is new.

done

[jeanbisutti]

LGTM

Thanks @zeitlinger!