feat(tracing): dont trace spans with full URL path names in ExtractFr…

…omHTTPRequest

go.mod

@@ -112,3 +112,5 @@ replace github.com/Sirupsen/logrus => github.com/sirupsen/logrus v1.2.0
 replace github.com/influxdata/platform => /dev/null
 
 replace github.com/goreleaser/goreleaser => github.com/influxdata/goreleaser v0.97.0-influx
+
+replace github.com/julienschmidt/httprouter => github.com/georgemac/httprouter v1.3.1-0.20191121142037-34e411acc501

go.sum

@@ -113,6 +113,10 @@ github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 h1:BHsljHzVlRcyQhjr
 github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI435gkrCt3MPfRiAkVrwSbHsst4LCFVfpJc=
 github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/georgemac/httprouter v1.3.1-0.20191005171706-08a3b3d20bbe h1:AQVSvv8BnA3cE3JKyxbuQMTREPrfFQ3FO3t0WX0OHT4=
+github.com/georgemac/httprouter v1.3.1-0.20191005171706-08a3b3d20bbe/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
+github.com/georgemac/httprouter v1.3.1-0.20191121142037-34e411acc501 h1:eSe2KTNWsu40zA8mT/lJ7y+XnthfQ5umHyHUiLXnKb8=
+github.com/georgemac/httprouter v1.3.1-0.20191121142037-34e411acc501/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/getkin/kin-openapi v0.2.0 h1:PbHHtYZpjKwZtGlIyELgA2DploRrsaXztoNNx9HjwNY=
 github.com/getkin/kin-openapi v0.2.0/go.mod h1:V1z9xl9oF5Wt7v32ne4FmiF1alpS4dM6mNzoywPOXlk=
 github.com/ghodss/yaml v1.0.0 h1:wQHKEahhL6wmXdzwWG11gIVCkOv05bNOh+Rxn0yngAk=
@@ -267,8 +271,6 @@ github.com/jsternberg/zap-logfmt v1.2.0 h1:1v+PK4/B48cy8cfQbxL4FmmNZrjnIMr2BsnyE
 github.com/jsternberg/zap-logfmt v1.2.0/go.mod h1:kz+1CUmCutPWABnNkOu9hOHKdT2q3TDYCcsFy9hpqb0=
 github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
-github.com/julienschmidt/httprouter v1.2.0 h1:TDTW5Yz1mjftljbcKqRcrYhd4XeOoI98t+9HbQbYf7g=
-github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
 github.com/jwilder/encoding v0.0.0-20170811194829-b4e1701a28ef h1:2jNeR4YUziVtswNP9sEFAI913cVrzH85T+8Q6LpYbT0=
 github.com/jwilder/encoding v0.0.0-20170811194829-b4e1701a28ef/go.mod h1:Ct9fl0F6iIOGgxJ5npU/IUOhOhqlVrGjyIZc8/MagT0=
 github.com/k0kubun/colorstring v0.0.0-20150214042306-9440f1994b88 h1:uC1QfSlInpQF+M0ao65imhwqKnz3Q2z/d8PWZRMQvDM=

http/router.go

@@ -22,6 +22,7 @@ func NewRouter(h platform.HTTPErrorHandler) *httprouter.Router {
 	router.NotFound = http.HandlerFunc(b.notFound)
 	router.MethodNotAllowed = http.HandlerFunc(b.methodNotAllowed)
 	router.PanicHandler = b.panic
+	router.AddMatchedRouteToContext = true
 	return router
 }
 

kit/tracing/tracing.go

@@ -7,6 +7,7 @@ import (
 	"runtime"
 	"strings"
 
+	"github.com/julienschmidt/httprouter"
 	"github.com/opentracing/opentracing-go"
 	"github.com/opentracing/opentracing-go/ext"
 	"github.com/opentracing/opentracing-go/log"
@@ -50,15 +51,26 @@ func InjectToHTTPRequest(span opentracing.Span, req *http.Request) {
 func ExtractFromHTTPRequest(req *http.Request, handlerName string) (opentracing.Span, *http.Request) {
 	spanContext, err := opentracing.GlobalTracer().Extract(opentracing.HTTPHeaders, opentracing.HTTPHeadersCarrier(req.Header))
 	if err != nil {
-		span, ctx := opentracing.StartSpanFromContext(req.Context(), handlerName+":"+req.URL.Path)
-		LogError(span, err)
-		req = req.WithContext(ctx)
-		return span, req
+		span, ctx := opentracing.StartSpanFromContext(req.Context(), "request")
+		annotateSpan(span, handlerName, req)
+
+		_ = LogError(span, err)
+
+		return span, req.WithContext(ctx)
 	}
 
-	span := opentracing.StartSpan(handlerName+":"+req.URL.Path, opentracing.ChildOf(spanContext), ext.RPCServerOption(spanContext))
-	req = req.WithContext(opentracing.ContextWithSpan(req.Context(), span))
-	return span, req
+	span := opentracing.StartSpan("request", opentracing.ChildOf(spanContext), ext.RPCServerOption(spanContext))
+	annotateSpan(span, handlerName, req)
+
+	return span, req.WithContext(opentracing.ContextWithSpan(req.Context(), span))
+}
+
+func annotateSpan(span opentracing.Span, handlerName string, req *http.Request) {
+	if route := httprouter.MatchedRouteFromContext(req.Context()); route != "" {
+		span.SetTag("route", route)
+	}
+	span.SetTag("handler", handlerName)
+	span.LogKV("path", req.URL.Path)
 }
 
 // StartSpanFromContext is an improved opentracing.StartSpanFromContext.

kit/tracing/tracing_test.go

@@ -4,9 +4,11 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"net/url"
 	"runtime"
 	"testing"
 
+	"github.com/julienschmidt/httprouter"
 	"github.com/opentracing/opentracing-go"
 	"github.com/opentracing/opentracing-go/mocktracer"
 )
@@ -37,6 +39,83 @@ func TestInjectAndExtractHTTPRequest(t *testing.T) {
 	}
 }
 
+func TestExtractHTTPRequest(t *testing.T) {
+	var (
+		tracer    = mocktracer.New()
+		oldTracer = opentracing.GlobalTracer()
+		ctx       = context.Background()
+	)
+
+	opentracing.SetGlobalTracer(tracer)
+	defer opentracing.SetGlobalTracer(oldTracer)
+
+	for _, test := range []struct {
+		name        string
+		handlerName string
+		path        string
+		ctx         context.Context
+		tags        map[string]interface{}
+	}{
+		{
+			name:        "happy path",
+			handlerName: "WriteHandler",
+			ctx:         context.WithValue(ctx, httprouter.MatchedRouteKey, "/api/v2/write"),
+			path:        "/api/v2/write",
+			tags: map[string]interface{}{
+				"route":   "/api/v2/write",
+				"handler": "WriteHandler",
+			},
+		},
+		{
+			name:        "happy path bucket handler",
+			handlerName: "BucketHandler",
+			ctx:         context.WithValue(ctx, httprouter.MatchedRouteKey, "/api/v2/buckets/:bucket_id"),
+			path:        "/api/v2/buckets/12345",
+			tags: map[string]interface{}{
+				"route":   "/api/v2/buckets/:bucket_id",
+				"handler": "BucketHandler",
+			},
+		},
+		{
+			name:        "empty path",
+			handlerName: "Home",
+			ctx:         ctx,
+			tags: map[string]interface{}{
+				"handler": "Home",
+			},
+		},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			request, err := http.NewRequest(http.MethodPost, "http://localhost"+test.path, nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			span := tracer.StartSpan("operation name")
+
+			InjectToHTTPRequest(span, request)
+			gotSpan, _ := ExtractFromHTTPRequest(request.WithContext(test.ctx), test.handlerName)
+
+			if op := gotSpan.(*mocktracer.MockSpan).OperationName; op != "request" {
+				t.Fatalf("operation name %q != request", op)
+			}
+
+			tags := gotSpan.(*mocktracer.MockSpan).Tags()
+			for k, v := range test.tags {
+				found, ok := tags[k]
+				if !ok {
+					t.Errorf("tag not found in span %q", k)
+					continue
+				}
+
+				if found != v {
+					t.Errorf("expected %v, found %v for tag %q", v, found, k)
+				}
+			}
+		})
+	}
+}
+
 func TestStartSpanFromContext(t *testing.T) {
 	tracer := mocktracer.New()
 
@@ -219,3 +298,15 @@ func BenchmarkOpentracing_StartSpan_child(b *testing.B) {
 		_ = opentracing.StartSpan("operation name", opentracing.ChildOf(parentSpan.Context()))
 	}
 }
+
+func BenchmarkOpentracing_ExtractFromHTTPRequest(b *testing.B) {
+	b.ReportAllocs()
+
+	req := &http.Request{
+		URL: &url.URL{Path: "/api/v2/organization/12345"},
+	}
+
+	for n := 0; n < b.N; n++ {
+		_, _ = ExtractFromHTTPRequest(req, "OrganizationHandler")
+	}
+}