fix: Recognize OTEL_EXPORTER_OTLP_ENDPOINT as custom endpoint in Lambda environment

[garysassano]

Fixes #297

Solution

Updated hasCustomOtlpTraceEndpoint() to also check for the generic OTEL_EXPORTER_OTLP_ENDPOINT environment variable, per the OpenTelemetry OTLP Exporter specification:

function hasCustomOtlpTraceEndpoint() {
  // Check for signal-specific endpoint first, then fall back to generic endpoint
  // per OpenTelemetry OTLP Exporter specification
  return (
    process.env['OTEL_EXPORTER_OTLP_TRACES_ENDPOINT'] !== undefined ||
    process.env['OTEL_EXPORTER_OTLP_ENDPOINT'] !== undefined
  );
}

Changes

• aws-distro-opentelemetry-node-autoinstrumentation/src/aws-opentelemetry-configurator.ts: Updated hasCustomOtlpTraceEndpoint() to recognize both OTEL_EXPORTER_OTLP_TRACES_ENDPOINT and OTEL_EXPORTER_OTLP_ENDPOINT as custom endpoints.
• aws-distro-opentelemetry-node-autoinstrumentation/test/aws-opentelemetry-configurator.test.ts: Added test case to verify that setting OTEL_EXPORTER_OTLP_ENDPOINT in Lambda environment uses OTLP exporter instead of UDP.

[wangzlei]

@garysassano Thanks for the contribution! This issue might happen in other language SDKs as well, we will audit if it should be applied to other SDK repos.

[garysassano]

I audited the other language SDKs and attempted fixes:

Language	Status	Details
.NET	✅ Already fixed	HasCustomTracesEndpoint() already checks both endpoints
Python	🔄 PR opened	#562 - same pattern as this JS fix
Java	❌ Needs fix	Same issue exists, but couldn't run tests since project requires internal ADOT-patched Maven dependencies (opentelemetry-aws-xray:1.48.0-adot1) not available in public repos