Config using env variables - does setting OTEL_EXPORTER_OTLP_PROTOCOL have any effect?

[tekul]

I can see that this variable is used in WithExportConfig which is implemented for TonicExporterBuilder and HttpExporterBuilder but this seems back to front since its value should presumably determine which of these is used? As far as I can see, the value isn't used after being set. For example, this unit test seems to be setting a tonic exporter to use http/protobuf.

When putting together an example recently that was configured through the environment, I checked the variable myself before deciding which kind of exporter to create and configure.

Another thing in that example, was that I had to also check OTEL_EXPORTER_OTLP_ENDPOINT when using tonic in order to decide whether it needed to be configured with TLS or not.

It would be nice if these things were handled out of the box, maybe at the level of OtlpTracePipeline? Or maybe it is already possible and I've missed something 🙂.