Switch to go.opentelemetry.io API for tracing

go.mod

 module git.autistici.org/ai3/go-common
 
-go 1.11
+go 1.14
 
 require (
-	contrib.go.opencensus.io/exporter/zipkin v0.1.2
 	github.com/NYTimes/gziphandler v1.1.1
 	github.com/amoghe/go-crypt v0.0.0-20220222110647-20eada5f5964
 	github.com/bbrks/wrap/v2 v2.5.0
@@ -15,14 +14,17 @@ require (
 	github.com/go-asn1-ber/asn1-ber v1.5.4
 	github.com/go-ldap/ldap/v3 v3.4.4
 	github.com/gofrs/flock v0.8.0 // indirect
-	github.com/google/go-cmp v0.5.6
+	github.com/google/go-cmp v0.5.8
 	github.com/lunixbochs/struc v0.0.0-20200707160740-784aaebc1d40
 	github.com/miscreant/miscreant.go v0.0.0-20200214223636-26d376326b75
-	github.com/openzipkin/zipkin-go v0.4.0
 	github.com/prometheus/client_golang v1.12.2
 	github.com/russross/blackfriday/v2 v2.1.0
 	github.com/theckman/go-flock v0.8.1
 	go.opencensus.io v0.23.0
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.34.0
+	go.opentelemetry.io/otel v1.9.1-0.20220810155701-d96e8d2912af
+	go.opentelemetry.io/otel/exporters/zipkin v1.9.0
+	go.opentelemetry.io/otel/sdk v1.9.0
 	golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d
 	golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4
 )

tracing/tracing.go

@@ -11,11 +11,10 @@ import (
 	"strconv"
 	"sync"
 
-	openzipkin "github.com/openzipkin/zipkin-go"
-	zipkinHTTP "github.com/openzipkin/zipkin-go/reporter/http"
-	"contrib.go.opencensus.io/exporter/zipkin"
-	"go.opencensus.io/plugin/ochttp"
-	"go.opencensus.io/trace"
+	othttp "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/zipkin"
+	"go.opentelemetry.io/otel/sdk/trace"
 )
 
 var (
@@ -97,31 +96,33 @@ func initTracing(endpointAddr string) {
 		return
 	}
 	initOnce.Do(func() {
-		localEndpoint, err := openzipkin.NewEndpoint(getServiceName(), endpointAddr)
+		ze, err := zipkin.New(config.ReportURL)
 		if err != nil {
-			log.Printf("warning: error creating tracing endpoint: %v, tracing disabled", err)
+			log.Printf("error creating Zipkin exporter: %v", err)
 			return
 		}
 
-		reporter := zipkinHTTP.NewReporter(config.ReportURL)
-		ze := zipkin.NewExporter(reporter, localEndpoint)
-		trace.RegisterExporter(ze)
-
-		var tc trace.Config
+		var sampler trace.Sampler
 		switch config.Sample {
 		case "", "always":
-			tc.DefaultSampler = trace.AlwaysSample()
+			sampler = trace.AlwaysSample()
 		case "never":
-			tc.DefaultSampler = trace.NeverSample()
+			sampler = trace.NeverSample()
 		default:
 			frac, err := strconv.ParseFloat(config.Sample, 64)
 			if err != nil {
 				log.Printf("warning: error in tracing configuration: sample: %v, tracing disabled", err)
 				return
 			}
-			tc.DefaultSampler = trace.ProbabilitySampler(frac)
+			sampler = trace.TraceIDRatioBased(frac)
 		}
-		trace.ApplyConfig(tc)
+
+		tp := trace.NewTracerProvider(
+			trace.WithSampler(sampler),
+			trace.WithBatcher(ze),
+		)
+
+		otel.SetTracerProvider(tp)
 
 		log.Printf("tracing enabled (report_url %s)", config.ReportURL)
 
@@ -138,7 +139,7 @@ func Init() {
 // tracing functionality, if it is globally enabled.
 func WrapTransport(t http.RoundTripper) http.RoundTripper {
 	if Enabled {
-		t = &ochttp.Transport{Base: t}
+		t = othttp.NewTransport(t)
 	}
 	return t
 }
@@ -148,7 +149,7 @@ func WrapTransport(t http.RoundTripper) http.RoundTripper {
 func WrapHandler(h http.Handler, endpointAddr string) http.Handler {
 	if Enabled {
 		initTracing(endpointAddr)
-		h = &ochttp.Handler{Handler: h}
+		h = othttp.NewHandler(h, getServiceName())
 	}
 	return h
 }