Respect OTLP Exporter environment when configuring exporters

[mheffner]

Is your feature request related to a problem? Please describe.

I made the assumption I could change the exporter config on the NodeJS Lambda layer by setting OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf, however it appears to be hard-coded in the NodeJS Lambda layer to http/json.

Describe the solution you'd like

When using the NodeSDK directly it allows you to configure the exporters from the environment. Naturally, it feels like you should be able to configure the NodeJS OpenTelemetry Lambda layer using similar environment.

The solution I'd propose is respecting the similar environment variables, so that using the NodeJS Lambda layer behaves similarly to using the Node SDK.

[serkan-ozal]

Hi @mheffner,

Yes, unfortunately it is hard-coded to drop dependencies of other exporter libraries for reducing coldstart overhead. Let us check what we can do to handle loading/initializing those modules dynamically with webpack bundle.