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.