[sdk-node] automatically configure exporters based on enviornment variables

[jakobjoachim]

Issue I'm facing

The open-telemetry spec defines environment variables that specify which metric / logs / trace reader should be used.
There is currently no way of automatically configuring the instrumentation using these variables.
This is especially useful when using the Kubernetes auto instrumentation.

Describe the solution you'd like

A function that reads the env vars and returns the corresponding metric reader. Maybe getMetricReaderFromEnv().
Same thing for logs and traces.
Similar to how we have a getNodeAutoInstrumentations() function already.

Additional context

This solution was also discussed in a pr in the auto instrumentation project. see: here

[pichlermarc]

Hi, the trace part of this already exists (not specifying any trace exporter or span exporter in code, NodeSDK will set up an exporter according to the specification (using the OTEL_EXPORTER_TRACE env var.)

To add support for env var configuration for logs, we'll first need to tackle #3826

I'm marking this up-for-grabs as metrics is already in a state where this could be implemented 🙂

[psk001]

As #3826 is solved by pr #3969 , can I go ahead and implement this?

[pichlermarc]

@psk001 sure, go ahead once #3826 is merged. 🙂 Ideally, this function would be internal to the @opentelemetry/sdk-node module, so that it is used as the default behavior if no logging SDK is specified. Currently, the trace setup is way different, so there's not really a precedence impelemtnation to work on.

[psk001]

Great, waiting for #3969 to get merged 🙂

[github-actions]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 14 days.

[pichlermarc]

@psk001 are you still working on the remaining parts of this issue? Otherwise, I'll unassign to indicate that others can pick this up. 🙂

[github-actions]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 14 days.

[pichlermarc]

I'll split this into two sub-issues that can be done independently of each-other:

• [sdk-node] automatically configure metrics exporter based on enviornment variables #4551
• [sdk-node] automatically configure logs exporter based on enviornment variables #4552