add further refactoring

Author: liustve

aws-distro-opentelemetry-node-autoinstrumentation/src/exporter/otlp/aws/common/aws-authenticator.ts

@@ -22,6 +22,8 @@ if (getNodeVersion() >= 16) {
 } else {
   diag.error('SigV4 signing requires at least Node major version 16');
 }
+// See: https://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-authenticating-requests.html
+const SIG_V4_HEADERS = ['x-amz-date', 'authorization', 'x-amz-content-sha256', 'x-amz-security-token'];
 
 export class AwsAuthenticator {
   private region: string;
@@ -80,10 +82,9 @@ export class AwsAuthenticator {
   // Cleans up Sigv4 from headers to avoid accidentally copying them to the new headers
   private removeSigV4Headers(headers: Record<string, string>) {
     const newHeaders: Record<string, string> = {};
-    const sigV4Headers = ['x-amz-date', 'authorization', 'x-amz-content-sha256', 'x-amz-security-token'];
 
     for (const key in headers) {
-      if (!sigV4Headers.includes(key.toLowerCase())) {
+      if (!SIG_V4_HEADERS.includes(key.toLowerCase())) {
         newHeaders[key] = headers[key];
       }
     }

aws-distro-opentelemetry-node-autoinstrumentation/src/exporter/otlp/aws/logs/otlp-aws-log-exporter.ts

@@ -8,6 +8,7 @@ import { ReadableLogRecord } from '@opentelemetry/sdk-logs';
 import { AwsAuthenticator } from '../common/aws-authenticator';
 import { ExportResult, ExportResultCode } from '@opentelemetry/core';
 import { PassthroughSerializer } from '../common/passthrough-serializer';
+import { diag } from '@opentelemetry/api';
 
 /**
  * This exporter extends the functionality of the OTLPProtoLogExporter to allow spans to be exported
@@ -91,6 +92,8 @@ export class OTLPAwsLogExporter extends OTLPProtoLogExporter {
 
       const newHeaders: () => Record<string, string> = () => signedRequest;
       this['_delegate']._transport._transport._parameters.headers = newHeaders;
+    } else {
+      diag.debug('Delegate headers is undefined - unable to authenticate request to CloudWatch Logs OTLP endpoint');
     }
 
     super.export(items, resultCallback);

aws-distro-opentelemetry-node-autoinstrumentation/src/exporter/otlp/aws/traces/otlp-aws-span-exporter.ts

@@ -8,6 +8,7 @@ import { ExportResult, ExportResultCode } from '@opentelemetry/core';
 import { AwsAuthenticator } from '../common/aws-authenticator';
 import { PassthroughSerializer } from '../common/passthrough-serializer';
 import { gzipSync } from 'zlib';
+import { diag } from '@opentelemetry/api';
 
 /**
  * This exporter extends the functionality of the OTLPProtoTraceExporter to allow spans to be exported
@@ -80,6 +81,8 @@ export class OTLPAwsSpanExporter extends OTLPProtoTraceExporter {
       // See type: https://github.com/open-telemetry/opentelemetry-js/blob/experimental/v0.57.1/experimental/packages/otlp-exporter-base/src/transport/http-transport-types.ts#L31
       const newHeaders: () => Record<string, string> = () => signedRequest;
       this['_delegate']._transport._transport._parameters.headers = newHeaders;
+    } else {
+      diag.debug('Delegate headers is undefined - unable to authenticate request to XRay OTLP endpoint');
     }
 
     super.export(items, resultCallback);