inject env begining with prefix "OTEL_"

[elvis-cai]

Hi

we are using otel operator to inject splunk otel java library, and from the doc https://docs.splunk.com/observability/gdi/get-data-in/application/java/instrumentation/instrument-java-application.html#deploy-the-java-agent-in-kubernetes, we also need inject env starting with prefix SPLUNK_, and from the code https://github.com/open-telemetry/opentelemetry-operator/blob/main/apis/v1alpha1/instrumentation_webhook.go#L134 it is hardcoded to OTEL, just wondering is it possible we could inject env other than OTEL_ to make operator more generic? thanks.

[pavolloffay]

The main reason that the operator uses only OTEL_ prefix is to avoid people using the instrumentation CR to configure their apps.

Which env vars would you like to inject? It seems that the SPLUNK agent supports both OTEL_ and SPLUNK_ env vars. e.g.

SPLUNK_OTEL_AGENT - address to Splunk host agent
SPLUNK_ACCESS_TOKEN - the access token

I like the idea that the operator could work with vendor distributions. In this case we could support SPLUNK prefix as well.

[elvis-cai]

Thanks for the quick reply, here's all the envs for splunk otel java lib we could configure, https://docs.splunk.com/observability/gdi/get-data-in/application/java/configuration/advanced-java-otel-configuration.html#nav-Advanced-configuration.
The actively used ones for us are below, we might also need add SPLUNK_PROFILER_xx related in future.

• SPLUNK_METRICS_ENABLED
• SPLUNK_METRICS_ENDPOINT
• SPLUNK_OTEL_AGENT

And yes SPlunk distributed java library supports all the features of the OpenTelemetry Instrumentation for Java and added extra features as the link mentioned here https://docs.splunk.com/observability/gdi/get-data-in/application/java/splunk-java-otel-distribution.html#features-of-the-splunk-distribution-of-opentelemetry-java, thay may explain it supports OTEL and SPLUNK prefix.

[pavolloffay]

@elvis-cai would you like to submit a PR to fix this?

[elvis-cai]

sure.