Send unsupported registered span tags as data.custom map

instana · Apr 20, 2021 · 82c1900 · 82c1900
1 parent 5e6fb9e
commit 82c1900
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Showing 2 changed files with 60 additions and 2 deletions.
diff --git a/json_span.go b/json_span.go
@@ -166,11 +166,33 @@ type batchInfo struct {
 	Size int `json:"s"`
 }
 
+// CustomSpanData holds user-defined span tags
+type CustomSpanData struct {
+	Tags map[string]interface{} `json:"tags,omitempty"`
+}
+
+func filterCustomSpanTags(tags map[string]interface{}, st RegisteredSpanType) map[string]interface{} {
+	knownTags := st.TagsNames()
+	customTags := make(map[string]interface{})
+
+	for k, v := range tags {
+		if _, ok := knownTags[k]; ok {
+			continue
+		}
+
+		customTags[k] = v
+	}
+
+	return customTags
+}
+
 // SpanData contains fields to be sent in the `data` section of an OT span document. These fields are
 // common for all span types.
 type SpanData struct {
-	Service string `json:"service,omitempty"`
-	st      RegisteredSpanType
+	Service string          `json:"service,omitempty"`
+	Custom  *CustomSpanData `json:"custom,omitempty"`
+
+	st RegisteredSpanType
 }
 
 // NewSpanData initializes a new span data from tracer span
@@ -180,6 +202,10 @@ func NewSpanData(span *spanS, st RegisteredSpanType) SpanData {
 		st:      st,
 	}
 
+	if customTags := filterCustomSpanTags(span.Tags, st); len(customTags) > 0 {
+		data.Custom = &CustomSpanData{Tags: customTags}
+	}
+
 	return data
 }
 

diff --git a/json_span_test.go b/json_span_test.go
@@ -74,3 +74,35 @@ func TestNewSDKSpanData(t *testing.T) {
 		},
 	}, data.Tags)
 }
+
+func TestSpanData_CustomTags(t *testing.T) {
+	recorder := instana.NewTestRecorder()
+	tracer := instana.NewTracerWithEverything(&instana.Options{}, recorder)
+
+	sp := tracer.StartSpan("g.http", opentracing.Tags{
+		"http.host":   "localhost",
+		"http.path":   "/",
+		"custom.tag":  "42",
+		"another.tag": true,
+	})
+	sp.Finish()
+
+	spans := recorder.GetQueuedSpans()
+	require.Len(t, spans, 1)
+
+	span := spans[0]
+	require.IsType(t, instana.HTTPSpanData{}, span.Data)
+
+	data := span.Data.(instana.HTTPSpanData)
+
+	assert.Equal(t, instana.HTTPSpanTags{
+		Host: "localhost",
+		Path: "/",
+	}, data.Tags)
+	assert.Equal(t, &instana.CustomSpanData{
+		Tags: map[string]interface{}{
+			"custom.tag":  "42",
+			"another.tag": true,
+		},
+	}, data.Custom)
+}