Elastic APM Go - path generator

topo-apm.go

package main

import (
	"fmt"

	"go.elastic.co/apm"
)

type node struct {
	tracer *apm.Tracer
}

func makeNode(name, version, env string) *node {
	t, err := apm.NewTracerOptions(apm.TracerOptions{
		ServiceName:        name,
		ServiceVersion:     version,
		ServiceEnvironment: env,
	})
	if err != nil {
		panic(err)
	}
	return &node{tracer: t}
}

func flushAll(nodes ...*node) {
	for _, n := range nodes {
		n.tracer.Flush(nil)
	}
}

func makePath(nodes ...*node) {
	var traceContext apm.TraceContext
	for i, n := range nodes {
		tx := n.tracer.StartTransactionOptions(
			fmt.Sprintf("GET /%s", n.tracer.Service.Name), "request",
			apm.TransactionOptions{TraceContext: traceContext},
		)
		defer tx.End()

		if i < len(nodes)-1 {
			name := fmt.Sprintf("GET %s", nodes[i+1].tracer.Service.Name)
			span := tx.StartSpan(name, "external.http", nil)
			defer span.End()
			traceContext = span.TraceContext()
		}
	}
}

func main() {
	/*
		n1              n4 (n2 -> n3 -> n4)
		  \            /
		   ---- n3 ----
		  /            \
		n2              n5 (n1 -> n3 -> n5)
	*/
	n1 := makeNode("n1", "1.0.0", "production")
	n2 := makeNode("n2", "1.0.0", "production")
	n3 := makeNode("n3", "1.0.0", "production")
	n4 := makeNode("n4", "1.0.0", "production")
	n5 := makeNode("n5", "1.0.0", "production")
	defer flushAll(n1, n2, n3, n4, n5)

	makePath(n2, n3, n4)
	makePath(n1, n3, n5)
}