Add links and events to tracing payload (#21)

* add links

* remove test artifact

* add templated events and links

* use random factor for rates & merge defaults+random

* making linking to previous span a default until we can support specific linkage

* lint

* fix template example, rename defaults

* oops forgot to undo testing

Author: ie-pham

examples/template/template.js

@@ -21,7 +21,9 @@ const client = new tracing.Client({
 const traceDefaults = {
     attributeSemantics: tracing.SEMANTICS_HTTP,
     attributes: {"one": "three"},
-    randomAttributes: {count: 2, cardinality: 5}
+    randomAttributes: {count: 2, cardinality: 5},
+    randomEvents: {generateExceptionOnError: true, rate: 1.0, randomAttributes: {count: 2, cardinality: 3}},
+    randomLinks: {rate: 1.0, randomAttributes: {count: 2, cardinality: 3}},
 }
 
 const traceTemplates = [
@@ -63,6 +65,16 @@ const traceTemplates = [
             {service: "auth-service", name: "authenticate", attributes: {"http.status_code": 403}},
         ]
     },
+    {
+        defaults: traceDefaults,
+        spans: [
+            {service: "shop-backend", attributes: {"http.status_code": 403}},
+            {service: "shop-backend", name: "authenticate", attributes: {"http.request.header.accept": ["application/json"]}},
+            {service: "auth-service", name: "authenticate", attributes: {"http.status_code": 403}},
+            {service: "cart-service", name: "checkout", randomEvents: {exceptionRate: 1, rate: 2, randomAttributes: {count: 5, cardinality: 2}}},
+            {service: "billing-service", name: "payment", randomLinks: {rate: 2, randomAttributes: {count: 3, cardinality: 2}}}
+        ]
+    },
 ]
 
 export default function () {

pkg/tracegen/parameterized.go

@@ -114,7 +114,12 @@ func (g *ParameterizedGenerator) generateSpan(t *TraceParams, dest ptrace.Span)
 	event := span.Events().AppendEmpty()
 	event.SetName(random.K6String(12))
 	event.SetTimestamp(pcommon.NewTimestampFromTime(startTime))
-	event.Attributes().PutStr(random.K6String(12), random.K6String(12))
+	event.Attributes().PutStr(random.K6String(5), random.K6String(12))
+
+	link := span.Links().AppendEmpty()
+	link.SetTraceID(traceID)
+	link.SetSpanID(random.SpanID())
+	link.Attributes().PutStr(random.K6String(12), random.K6String(12))
 
 	status := span.Status()
 	status.SetCode(1)