first working version, emits traces but all spans are disconnected

.gitignore

@@ -1,3 +1,4 @@
 .vscode
-
+*.json
 dist/
+fortiotel

Makefile

@@ -8,3 +8,12 @@ docker-test:
 	GOOS=linux go build
 	docker build . --tag fortio/fortiotel:test
 	docker run fortio/fortiotel:test
+
+start-local-jaeger:
+	docker run -d --name jaeger -p 16686:16686 -p 4317:4317 jaegertracing/all-in-one:latest \
+		--collector.otlp.enabled=true --collector.otlp.grpc.host-port=:4317
+	@echo "Jaeger UI:\nhttp://localhost:16686"
+
+stop-local-jaeger:
+	docker stop jaeger
+	docker rm jaeger

README.md

@@ -14,6 +14,20 @@ You can also download one of the many binary [releases](https://github.com/forti
 
 We publish a multi architecture docker image (linux/amd64, linux/arm64) `docker run fortio/fortiotel`
 
+# Testing:
+
+Start a local jaeger with otel receiver:
+```
+docker run -p 16686:16686 -p 4317:4317 jaegertracing/all-in-one:latest --collector.otlp.enabled=true --collector.otlp.grpc.host-port=:4317
+```
+
+Run fortio server and then for instance:
+```
+go run . load localhost:8080
+```
+
+Get disjoint traces (for now): http://localhost:16686/search
+
 # Documentation
 
 Loosely based on

fortio_with_otel.go

@@ -17,12 +17,17 @@ package main
 import (
 	"context"
 	"flag"
+	"fmt"
 
 	"fortio.org/fortio/cli"
 	"fortio.org/fortio/fhttp"
 	"fortio.org/fortio/log"
 	"fortio.org/fortio/periodic"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 )
 
 // changeDefaults sets some flags to true by default instead of false.
@@ -38,12 +43,46 @@ func changeDefaults(flagNames []string) {
 	}
 }
 
+// Sort of inspired from
+// https://github.com/open-telemetry/opentelemetry-go/blob/main/exporters/otlp/otlptrace/otlptracehttp/example_test.go
+
+func installExportPipeline(ctx context.Context) (func(context.Context) error, error) {
+	// Insecure needed for jaeger otel grpc endpoint by default/using all-in-one.
+	// (and istio envoy will mtls secure it when not running local tests anyway)
+	client := otlptracegrpc.NewClient(otlptracegrpc.WithInsecure())
+	exporter, err := otlptrace.New(ctx, client)
+	if err != nil {
+		return nil, fmt.Errorf("creating OTLP trace exporter: %w", err)
+	}
+
+	tracerProvider := sdktrace.NewTracerProvider(
+		sdktrace.WithBatcher(exporter),
+	)
+	otel.SetTracerProvider(tracerProvider)
+
+	return tracerProvider.Shutdown, nil
+}
+
+var shutdown func(context.Context) error
+
 func hook(ho *fhttp.HTTPOptions, ro *periodic.RunnerOptions) {
-	ho.ClientTrace = otelhttptrace.NewClientTrace(context.Background())
+	ctx := context.Background()
+	ho.ClientTrace = otelhttptrace.NewClientTrace(ctx)
+	// Registers a tracer Provider globally.
+	var err error
+	shutdown, err = installExportPipeline(ctx)
+	if err != nil {
+		log.Fatalf("Error setting up export pipeline: %v", err)
+	}
+	log.Infof("OTEL export pipeline setup successfully")
 }
 
 func main() {
 	// Change a bunch of defaults to better ones "2.0" afforded by this being a new binary.
 	changeDefaults([]string{"stdclient", "nocatchup", "uniform", "a"})
 	cli.FortioMain(hook)
+	if err := shutdown(context.Background()); err != nil {
+		log.Fatalf("Error shutting down up export pipeline: %v", err)
+	}
+	log.Infof("OTEL export pipeline shut down successfully")
 }

go.mod

@@ -5,24 +5,31 @@ go 1.18
 require (
 	fortio.org/fortio v1.39.0-pre4
 	go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace v0.36.4
+	go.opentelemetry.io/otel v1.11.1
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.11.1
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.11.1
+	go.opentelemetry.io/otel/sdk v1.11.1
 )
 
 // During development, point to local repo for fortio
 // replace fortio.org/fortio => ../fortio
 
 require (
+	github.com/cenkalti/backoff/v4 v4.1.3 // indirect
 	github.com/fsnotify/fsnotify v1.6.0 // indirect
 	github.com/go-logr/logr v1.2.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/uuid v1.3.0 // indirect
-	go.opentelemetry.io/otel v1.11.1 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.11.1 // indirect
 	go.opentelemetry.io/otel/trace v1.11.1 // indirect
+	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
 	golang.org/x/exp v0.0.0-20221111204811-129d8d6c17ab // indirect
 	golang.org/x/net v0.2.0 // indirect
 	golang.org/x/sys v0.2.0 // indirect
 	golang.org/x/text v0.4.0 // indirect
 	google.golang.org/genproto v0.0.0-20220714211235-042d03aeabc9 // indirect
 	google.golang.org/grpc v1.51.0 // indirect
-	google.golang.org/protobuf v1.28.0 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
 )