feat(tracing): switch to OpenTelemetry

Switch the underlying tracing library to OpenTelemetry, with a bridge to OpenCensus for
compatibility

lib/tracing/setup.go

@@ -4,9 +4,15 @@ import (
 	"os"
 	"strings"
 
-	"contrib.go.opencensus.io/exporter/jaeger"
+	octrace "go.opencensus.io/trace"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/bridge/opencensus"
+	"go.opentelemetry.io/otel/exporters/jaeger"
+	"go.opentelemetry.io/otel/sdk/resource"
+	tracesdk "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.7.0"
+
 	logging "github.com/ipfs/go-log/v2"
-	"go.opencensus.io/trace"
 )
 
 var log = logging.Logger("tracing")
@@ -14,7 +20,6 @@ var log = logging.Logger("tracing")
 const (
 	// environment variable names
 	envCollectorEndpoint = "LOTUS_JAEGER_COLLECTOR_ENDPOINT"
-	envAgentEndpoint     = "LOTUS_JAEGER_AGENT_ENDPOINT"
 	envAgentHost         = "LOTUS_JAEGER_AGENT_HOST"
 	envAgentPort         = "LOTUS_JAEGER_AGENT_PORT"
 	envJaegerUser        = "LOTUS_JAEGER_USERNAME"
@@ -26,54 +31,60 @@ const (
 // The agent endpoint is a thrift/udp protocol and should be given
 // as a string like "hostname:port". The agent can also be configured
 // with separate host and port variables.
-func jaegerOptsFromEnv(opts *jaeger.Options) bool {
+func jaegerOptsFromEnv() jaeger.EndpointOption {
 	var e string
 	var ok bool
-	if e, ok = os.LookupEnv(envJaegerUser); ok {
-		if p, ok := os.LookupEnv(envJaegerCred); ok {
-			opts.Username = e
-			opts.Password = p
-		} else {
-			log.Warn("jaeger username supplied with no password. authentication will not be used.")
-		}
-	}
+
 	if e, ok = os.LookupEnv(envCollectorEndpoint); ok {
-		opts.CollectorEndpoint = e
-		log.Infof("jaeger tracess will send to collector %s", e)
-		return true
-	}
-	if e, ok = os.LookupEnv(envAgentEndpoint); ok {
-		log.Infof("jaeger traces will be sent to agent %s", e)
-		opts.AgentEndpoint = e
-		return true
-	}
-	if e, ok = os.LookupEnv(envAgentHost); ok {
-		if p, ok := os.LookupEnv(envAgentPort); ok {
-			opts.AgentEndpoint = strings.Join([]string{e, p}, ":")
-		} else {
-			opts.AgentEndpoint = strings.Join([]string{e, "6831"}, ":")
+		options := []jaeger.CollectorEndpointOption{jaeger.WithEndpoint(e)}
+		if u, ok := os.LookupEnv(envJaegerUser); ok {
+			if p, ok := os.LookupEnv(envJaegerCred); ok {
+				options = append(options, jaeger.WithUsername(u))
+				options = append(options, jaeger.WithPassword(p))
+			} else {
+				log.Warn("jaeger username supplied with no password. authentication will not be used.")
+			}
 		}
-		log.Infof("jaeger traces will be sent to agent %s", opts.AgentEndpoint)
-		return true
+		log.Infof("jaeger tracess will send to collector %s", e)
+		return jaeger.WithCollectorEndpoint(options...)
 	}
-	return false
+
+	if e, ok = os.LookupEnv(envAgentHost); ok {
+		options := []jaeger.AgentEndpointOption{jaeger.WithAgentHost(e)}
+		var ep string
+		if p, ok := os.LookupEnv(envAgentPort); ok {
+			options = append(options, jaeger.WithAgentPort(p))
+			ep = strings.Join([]string{e, p}, ":")
+		} else {
+			ep = strings.Join([]string{e, "6831"}, ":")
+		}
+		log.Infof("jaeger traces will be sent to agent %s", ep)
+		return jaeger.WithAgentEndpoint(options...)
+	}
+	return nil
 }
 
-func SetupJaegerTracing(serviceName string) *jaeger.Exporter {
-	opts := jaeger.Options{}
-	if !jaegerOptsFromEnv(&opts) {
+func SetupJaegerTracing(serviceName string) *tracesdk.TracerProvider {
+	jaegerEndpoint := jaegerOptsFromEnv()
+	if jaegerEndpoint == nil {
 		return nil
 	}
-	opts.ServiceName = serviceName
-	je, err := jaeger.NewExporter(opts)
+	je, err := jaeger.New(jaegerEndpoint)
 	if err != nil {
 		log.Errorw("failed to create the jaeger exporter", "error", err)
 		return nil
 	}
-
-	trace.RegisterExporter(je)
-	trace.ApplyConfig(trace.Config{
-		DefaultSampler: trace.AlwaysSample(),
-	})
-	return je
+	tp := tracesdk.NewTracerProvider(
+		// Always be sure to batch in production.
+		tracesdk.WithBatcher(je),
+		// Record information about this application in an Resource.
+		tracesdk.WithResource(resource.NewWithAttributes(
+			semconv.SchemaURL,
+			semconv.ServiceNameKey.String(serviceName),
+		)),
+	)
+	otel.SetTracerProvider(tp)
+	tracer := tp.Tracer(serviceName)
+	octrace.DefaultTracer = opencensus.NewTracer(tracer)
+	return tp
 }