Default output file for OTLP JSON File exporter

[gaborcsardi]

I can see that the OTLP File exporter [1] is available now, which is great!

AFAICT there is no standard way to configure the output file(s), though. [2] says that OTEL_TRACES_EXPORTER=otlp/stdout should write it to standard output, but I could not find a standard to specify a file name or file name pattern in an env var. Am I missing something? Should such an env var exist?

[1] https://opentelemetry.io/docs/specs/otel/protocol/file-exporter/
[2] https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/#in-development-exporter-selection

[gaborcsardi]

There is a short, inconclusive discussion about env var names here: open-telemetry/opentelemetry-specification#3817