From 1eb145d115478557c6711a399609a16b52c0fc75 Mon Sep 17 00:00:00 2001
From: Marc Pichler <marc.pichler@dynatrace.com>
Date: Tue, 9 Apr 2024 18:30:16 +0200
Subject: [PATCH] feat(sdk-trace): add option to opt-out from merging the
 resource with Resource.default()

---
 .../opentelemetry-sdk-trace-base/src/BasicTracerProvider.ts | 6 +++++-
 packages/opentelemetry-sdk-trace-base/src/config.ts         | 1 +
 packages/opentelemetry-sdk-trace-base/src/types.ts          | 6 ++++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/packages/opentelemetry-sdk-trace-base/src/BasicTracerProvider.ts b/packages/opentelemetry-sdk-trace-base/src/BasicTracerProvider.ts
index c06f5cdcb61..0b3174767a5 100644
--- a/packages/opentelemetry-sdk-trace-base/src/BasicTracerProvider.ts
+++ b/packages/opentelemetry-sdk-trace-base/src/BasicTracerProvider.ts
@@ -80,7 +80,11 @@ export class BasicTracerProvider implements TracerProvider {
       reconfigureLimits(config)
     );
     this.resource = mergedConfig.resource ?? Resource.empty();
-    this.resource = Resource.default().merge(this.resource);
+
+    if (mergedConfig.mergeResourceWithDefaults) {
+      this.resource = Resource.default().merge(this.resource);
+    }
+
     this._config = Object.assign({}, mergedConfig, {
       resource: this.resource,
     });
diff --git a/packages/opentelemetry-sdk-trace-base/src/config.ts b/packages/opentelemetry-sdk-trace-base/src/config.ts
index 3448b793dad..7f06840e18c 100644
--- a/packages/opentelemetry-sdk-trace-base/src/config.ts
+++ b/packages/opentelemetry-sdk-trace-base/src/config.ts
@@ -54,6 +54,7 @@ export function loadDefaultConfig() {
       attributePerLinkCountLimit:
         getEnv().OTEL_SPAN_ATTRIBUTE_PER_LINK_COUNT_LIMIT,
     },
+    mergeResourceWithDefaults: true,
   };
 }
 
diff --git a/packages/opentelemetry-sdk-trace-base/src/types.ts b/packages/opentelemetry-sdk-trace-base/src/types.ts
index 99eeedbe817..64ae3b206bb 100644
--- a/packages/opentelemetry-sdk-trace-base/src/types.ts
+++ b/packages/opentelemetry-sdk-trace-base/src/types.ts
@@ -34,6 +34,12 @@ export interface TracerConfig {
   /** Span Limits */
   spanLimits?: SpanLimits;
 
+  /**
+   * Merge resource with {@link Resource.default()}?
+   * Default: {@code true}
+   **/
+  mergeResourceWithDefaults?: boolean;
+
   /** Resource associated with trace telemetry  */
   resource?: IResource;