How to overwrite environment variables?

[sergimola]

I am looking for some input from the community to see how people usually handle this.

We have a bunch of Java services deployed using HelmCharts and we are in the process of introducing traces. To be on the safe side, we want to have the SDK disabled by default in all the services and then be able to enable it at some point, kind of as a feature toogle.

The idea was to have OTEL_SDK_DISABLED set to true in each HelmChart and then manage the different services with the OpenTelemetry Operator by leaveraging the Instrumentation and annotating our pods with this:

instrumentation.opentelemetry.io/inject-sdk: "true"

Then the Instrumentation object would have all the settings for the SDK centralised making it possible to set OTEL_SDK_DISABLED to false and therefore overwrite the original value in the pod.

This approach seems not to work and the existing env vars in the pod can't be overwritten with env vars coming from the Java agent.
Is that right?

What would be a good approach to achieve what we are trying to achieve?

I really appreciate your expert feedback! 🙏

[jkwatson]

This looks to be more of a kubernetes question than a java OTel SDK question.