Set default sampling priority to sampler-keep (#88)

* Set default sampling priority to sampler-keep * Add a test for missing sampling priority
DataDog · Aug 18, 2021 · de1c7f3 · de1c7f3
1 parent d6fcbc3
commit de1c7f3
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Showing 3 changed files with 26 additions and 1 deletion.
diff --git a/internal/testdata/non-proxy-with-missing-sampling-priority.json b/internal/testdata/non-proxy-with-missing-sampling-priority.json
@@ -0,0 +1,10 @@
+{
+  "my-custom-event": {
+    "hello": 100
+  },
+  "fake-id": "12345678910",
+  "headers": {
+    "X-Datadog-Trace-Id": "1231452342",
+    "X-Datadog-Parent-Id": "45678910"
+  }
+}
diff --git a/internal/trace/context.go b/internal/trace/context.go
@@ -148,7 +148,7 @@ func getDatadogTraceContextFromEvent(ctx context.Context, ev json.RawMessage) (T
 
 	samplingPriority, ok := lowercaseHeaders[samplingPriorityHeader]
 	if !ok {
-		return traceCtx, false
+		samplingPriority = "1" //sampler-keep
 	}
 
 	traceCtx[samplingPriorityHeader] = samplingPriority

diff --git a/internal/trace/context_test.go b/internal/trace/context_test.go
@@ -84,6 +84,21 @@ func TestGetDatadogTraceContextForTraceMetadataWithMixedCaseHeaders(t *testing.T
 	assert.Equal(t, expected, headers)
 }
 
+func TestGetDatadogTraceContextForTraceMetadataWithMissingSamplingPriority(t *testing.T) {
+	ctx := mockLambdaXRayTraceContext(context.Background(), mockXRayTraceID, mockXRayEntityID, true)
+	ev := loadRawJSON(t, "../testdata/non-proxy-with-missing-sampling-priority.json")
+
+	headers, ok := getDatadogTraceContextFromEvent(ctx, *ev)
+	assert.True(t, ok)
+
+	expected := TraceContext{
+		traceIDHeader:          "1231452342",
+		parentIDHeader:         "45678910",
+		samplingPriorityHeader: "1",
+	}
+	assert.Equal(t, expected, headers)
+}
+
 func TestGetDatadogTraceContextForInvalidData(t *testing.T) {
 	ctx := mockLambdaXRayTraceContext(context.Background(), mockXRayTraceID, mockXRayEntityID, true)
 	ev := loadRawJSON(t, "../testdata/invalid.json")