Merge pull request #25 from anyproto/fix-metric-panic

validate rpc method name

Makefile

@@ -25,7 +25,6 @@ deps:
 	go mod download
 	go build -o deps storj.io/drpc/cmd/protoc-gen-go-drpc
 	go build -o deps github.com/gogo/protobuf/protoc-gen-gogofaster
-	go build -o deps github.com/golang/mock/mockgen
 
 test:
 	go test ./... --cover

metric/drpc.go

@@ -2,8 +2,10 @@ package metric
 
 import (
 	"github.com/prometheus/client_golang/prometheus"
+	"go.uber.org/zap"
 	"storj.io/drpc"
 	"time"
+	"unicode/utf8"
 )
 
 type prometheusDRPC struct {
@@ -14,7 +16,11 @@ type prometheusDRPC struct {
 func (ph *prometheusDRPC) HandleRPC(stream drpc.Stream, rpc string) (err error) {
 	st := time.Now()
 	defer func() {
-		ph.SummaryVec.WithLabelValues(rpc).Observe(time.Since(st).Seconds())
+		if utf8.ValidString(rpc) {
+			ph.SummaryVec.WithLabelValues(rpc).Observe(time.Since(st).Seconds())
+		} else {
+			log.WarnCtx(stream.Context(), "invalid rpc string", zap.String("rpc", rpc))
+		}
 	}()
 	return ph.Handler.HandleRPC(stream, rpc)
 }