opentracing middleware

example/dataloader/server/server.go

@@ -3,15 +3,70 @@ package main
 import (
 	"log"
 	"net/http"
+	"net/url"
+	"time"
 
+	"github.com/go-chi/chi"
+	"github.com/opentracing-contrib/go-stdlib/nethttp"
+	"github.com/opentracing/opentracing-go"
 	"github.com/vektah/gqlgen/example/dataloader"
 	"github.com/vektah/gqlgen/handler"
+	gqlopentracing "github.com/vektah/gqlgen/opentracing"
+	"sourcegraph.com/sourcegraph/appdash"
+	appdashtracer "sourcegraph.com/sourcegraph/appdash/opentracing"
+	"sourcegraph.com/sourcegraph/appdash/traceapp"
 )
 
 func main() {
+
 	http.Handle("/", handler.Playground("Dataloader", "/query"))
 
-	http.Handle("/query", dataloader.LoaderMiddleware(handler.GraphQL(dataloader.MakeExecutableSchema(&dataloader.Resolver{}))))
+	tracer := startAppdashServer()
+
+	router := chi.NewRouter()
+	router.Use(Opentracing(tracer))
+	router.Use(dataloader.LoaderMiddleware)
+
+	router.Handle("/query", handler.GraphQL(dataloader.MakeExecutableSchema(&dataloader.Resolver{}), handler.Use(gqlopentracing.Middleware())))
+
+	log.Println("connect to http://localhost:8082/ for graphql playground")
+	log.Fatal(http.ListenAndServe(":8082", router))
+}
+
+func Opentracing(tracer opentracing.Tracer) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return nethttp.Middleware(tracer, next)
+	}
+}
+
+func startAppdashServer() opentracing.Tracer {
+	memStore := appdash.NewMemoryStore()
+	store := &appdash.RecentStore{
+		MinEvictAge: 5 * time.Minute,
+		DeleteStore: memStore,
+	}
+
+	url, err := url.Parse("http://localhost:8700")
+	if err != nil {
+		log.Fatal(err)
+	}
+	tapp, err := traceapp.New(nil, url)
+	if err != nil {
+		log.Fatal(err)
+	}
+	tapp.Store = store
+	tapp.Queryer = memStore
+
+	go func() {
+		log.Fatal(http.ListenAndServe(":8700", tapp))
+	}()
+	tapp.Store = store
+	tapp.Queryer = memStore
+
+	collector := appdash.NewLocalCollector(store)
+	tracer := appdashtracer.NewTracer(collector)
+	opentracing.InitGlobalTracer(tracer)
 
-	log.Fatal(http.ListenAndServe(":8082", nil))
+	log.Println("Appdash web UI running on HTTP :8700")
+	return tracer
 }

handler/graphql.go

@@ -1,14 +1,12 @@
 package handler
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
-
 	"strings"
 
-	"context"
-
 	"github.com/gorilla/websocket"
 	"github.com/vektah/gqlgen/graphql"
 	"github.com/vektah/gqlgen/neelance/errors"

opentracing/opentracing.go

@@ -0,0 +1,36 @@
+package opentracing
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/opentracing/opentracing-go"
+	"github.com/opentracing/opentracing-go/ext"
+	"github.com/opentracing/opentracing-go/log"
+	"github.com/vektah/gqlgen/graphql"
+)
+
+func Middleware() graphql.ResolverMiddleware {
+	return func(ctx context.Context, next graphql.Resolver) (interface{}, error) {
+		rctx := graphql.GetResolverContext(ctx)
+
+		fmt.Println("SPAN", rctx.Object+"_"+rctx.Field.Name)
+		span, ctx := opentracing.StartSpanFromContext(ctx, rctx.Object+"_"+rctx.Field.Name)
+		defer span.Finish()
+
+		res, err := next(ctx)
+
+		span.LogFields(
+			log.String("object", rctx.Object),
+			log.String("name", rctx.Field.Name),
+			log.String("alias", rctx.Field.Alias),
+		)
+
+		if err != nil {
+			ext.Error.Set(span, true)
+			span.LogFields(log.String("error", err.Error()))
+		}
+
+		return res, err
+	}
+}

test/resolvers_test.go

@@ -71,6 +71,9 @@ func TestErrorConverter(t *testing.T) {
 func mkctx(doc *query.Document, errFn func(e error) string) context.Context {
 	return graphql.WithRequestContext(context.Background(), &graphql.RequestContext{
 		Doc: doc,
+		Middleware: func(ctx context.Context, next graphql.Resolver) (res interface{}, err error) {
+			return next(ctx)
+		},
 		Builder: gqlerrors.Builder{
 			ErrorMessageFn: errFn,
 		},