Baggage support

packages/dd-trace/src/config.js

@@ -566,6 +566,9 @@ class Config {
     this._setValue(defaults, 'url', undefined)
     this._setValue(defaults, 'version', pkg.version)
     this._setValue(defaults, 'instrumentation_config_id', undefined)
+    this._setValue(defaults, 'baggagePropagation', true)
+    this._setValue(defaults, 'baggageInject', true)
+    this._setValue(defaults, 'baggageExtract', true)
   }
 
   _applyEnvironment () {

packages/dd-trace/src/opentracing/propagation/text_map.js

@@ -110,6 +110,10 @@ class TextMapPropagator {
     spanContext._baggageItems && Object.keys(spanContext._baggageItems).forEach(key => {
       carrier[baggagePrefix + key] = String(spanContext._baggageItems[key])
     })
+    if (this._config.baggageInject === false) return
+    if (this._config.baggageInject === true || this._config.baggagePropagation === true) {
+      carrier.baggage = JSON.stringify(spanContext._baggageItems)
+    }
   }
 
   _injectTags (spanContext, carrier) {
@@ -540,6 +544,13 @@ class TextMapPropagator {
         spanContext._baggageItems[match[1]] = carrier[key]
       }
     })
+    if (this._config.baggageExtract === false) return
+    if (this._config.baggageExtract === true || this._config.baggagePropagation === true) {
+      const baggages = JSON.parse(carrier.baggage)
+      for (const [key, value] of Object.entries(baggages)) {
+        spanContext._baggageItems[key] = spanContext._baggageItems[key] || value
+      }
+    }
   }
 
   _extractSamplingPriority (carrier, spanContext) {

packages/dd-trace/src/opentracing/span.js

@@ -145,6 +145,18 @@ class DatadogSpan {
     return this._spanContext._baggageItems[key]
   }
 
+  getAllBaggageItems () {
+    return this._spanContext._baggageItems
+  }
+
+  removeBaggageItem (key) {
+    delete this._spanContext._baggageItems[key]
+  }
+
+  removeAllBaggageItems () {
+    this._spanContext._baggageItems = {}
+  }
+
   setTag (key, value) {
     this._addTags({ [key]: value })
     return this