fix: remove gorilla usage in middlewares (#30)

go.mod

@@ -14,7 +14,6 @@ require (
 	github.com/go-openapi/strfmt v0.21.3
 	github.com/go-openapi/swag v0.21.1
 	github.com/go-openapi/validate v0.22.0
-	github.com/gorilla/mux v1.8.0
 	github.com/mitchellh/mapstructure v1.4.3
 	github.com/newrelic/go-agent/v3 v3.18.2
 	github.com/newrelic/newrelic-opencensus-exporter-go v0.4.0

go.sum

@@ -715,7 +715,6 @@ github.com/gorilla/handlers v1.4.2/go.mod h1:Qkdc/uu4tH4g6mTK6auzZ766c4CA0Ng8+o/
 github.com/gorilla/mux v1.7.2/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
 github.com/gorilla/mux v1.7.3/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
 github.com/gorilla/mux v1.7.4/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
-github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
 github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
 github.com/gorilla/websocket v0.0.0-20170926233335-4201258b820c/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=

internal/server/middlewares.go

@@ -6,18 +6,20 @@ import (
 	"strings"
 	"time"
 
-	gorillamux "github.com/gorilla/mux"
+	"github.com/go-chi/chi/v5"
+	"github.com/newrelic/go-agent/v3/newrelic"
 	"github.com/rs/xid"
 	"go.opencensus.io/plugin/ochttp"
 	"go.opencensus.io/tag"
 	"go.opencensus.io/trace"
 	"go.uber.org/zap"
 )
 
-const (
-	grpcGatewayPrefix = "/api"
-	headerRequestID   = "X-Request-Id"
-)
+const headerRequestID = "X-Request-Id"
+
+type curRouteFn func(r *http.Request) string
+
+type middleware func(http.Handler) http.Handler
 
 type wrappedWriter struct {
 	http.ResponseWriter
@@ -30,24 +32,44 @@ func (wr *wrappedWriter) WriteHeader(statusCode int) {
 	wr.ResponseWriter.WriteHeader(statusCode)
 }
 
-func withOpenCensus() gorillamux.MiddlewareFunc {
+func newRelicAPM(nrApp *newrelic.Application, curRoute curRouteFn) middleware {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			route := curRoute(r)
+			if route == "" {
+				route = r.URL.Path
+			}
+
+			txn := nrApp.StartTransaction(r.Method + " " + route)
+			defer txn.End()
+
+			w = txn.SetWebResponse(w)
+			txn.SetWebRequestHTTP(r)
+			r = newrelic.RequestWithTransactionContext(r, txn)
+
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+func withOpenCensus(curRoute curRouteFn) middleware {
 	return func(next http.Handler) http.Handler {
 		oc := &ochttp.Handler{
-			Handler:          next,
-			FormatSpanName:   formatSpanName,
+			Handler: next,
+			FormatSpanName: func(r *http.Request) string {
+				route := curRoute(r)
+				if route == "" {
+					route = r.URL.Path
+				}
+				return fmt.Sprintf("%s %s", r.Method, route)
+			},
 			IsPublicEndpoint: false,
 		}
-		return http.HandlerFunc(func(wr http.ResponseWriter, req *http.Request) {
-			route := gorillamux.CurrentRoute(req)
-
-			pathTpl := req.URL.Path
-			if route != nil {
-				pathTpl, _ = route.GetPathTemplate()
-			}
 
-			if strings.HasPrefix(pathTpl, grpcGatewayPrefix) {
-				// FIX: figure out a way to extract path-pattern from gateway requests.
-				pathTpl = "/api/"
+		return http.HandlerFunc(func(wr http.ResponseWriter, req *http.Request) {
+			pathTpl := curRoute(req)
+			if pathTpl == "" {
+				pathTpl = req.URL.Path
 			}
 
 			ctx, _ := tag.New(req.Context(),
@@ -60,7 +82,7 @@ func withOpenCensus() gorillamux.MiddlewareFunc {
 	}
 }
 
-func requestID() gorillamux.MiddlewareFunc {
+func requestID() middleware {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(wr http.ResponseWriter, req *http.Request) {
 			rid := strings.TrimSpace(req.Header.Get(headerRequestID))
@@ -78,7 +100,7 @@ func requestID() gorillamux.MiddlewareFunc {
 	}
 }
 
-func requestLogger(lg *zap.Logger) gorillamux.MiddlewareFunc {
+func requestLogger(lg *zap.Logger) middleware {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(wr http.ResponseWriter, req *http.Request) {
 			t := time.Now()
@@ -121,15 +143,14 @@ func requestLogger(lg *zap.Logger) gorillamux.MiddlewareFunc {
 	}
 }
 
-func formatSpanName(req *http.Request) string {
-	route := gorillamux.CurrentRoute(req)
-
-	pathTpl := req.URL.Path
-	if route != nil {
-		pathTpl, _ = route.GetPathTemplate()
+func currentRouteGetter(router chi.Router) func(r *http.Request) string {
+	return func(r *http.Request) string {
+		rCtx := chi.NewRouteContext()
+		if !router.Match(rCtx, r.Method, r.URL.Path) {
+			return ""
+		}
+		return rCtx.RoutePattern()
 	}
-
-	return fmt.Sprintf("%s %s", req.Method, pathTpl)
 }
 
 func is2xx(status int) bool {

internal/server/reqctx/middleware.go

@@ -3,8 +3,6 @@ package reqctx
 import (
 	"net/http"
 	"strings"
-
-	gorillamux "github.com/gorilla/mux"
 )
 
 // shield header names.
@@ -15,7 +13,7 @@ const (
 	headerRequestID = "X-Request-Id"
 )
 
-func WithRequestCtx() gorillamux.MiddlewareFunc {
+func WithRequestCtx() func(next http.Handler) http.Handler {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			reqID := strings.TrimSpace(r.Header.Get(headerRequestID))

internal/server/server.go

@@ -31,11 +31,12 @@ func Serve(ctx context.Context, addr string,
 	alertSvc := &alertsv1.Service{Siren: sirenClient}
 
 	router := chi.NewRouter()
+	curRoute := currentRouteGetter(router)
 	router.Use(
-		newRelicAPM(router, nrApp),
+		newRelicAPM(nrApp, curRoute),
 		requestID(),
 		reqctx.WithRequestCtx(),
-		withOpenCensus(),
+		withOpenCensus(curRoute),
 		requestLogger(logger), // nolint
 	)
 
@@ -56,25 +57,3 @@ func Serve(ctx context.Context, addr string,
 	logger.Info("starting server", zap.String("addr", addr))
 	return mux.Serve(ctx, addr, mux.WithHTTP(router))
 }
-
-func newRelicAPM(router chi.Router, nrApp *newrelic.Application) func(http.Handler) http.Handler {
-	return func(next http.Handler) http.Handler {
-		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			var txn *newrelic.Transaction
-
-			rCtx := chi.NewRouteContext()
-			if router.Match(rCtx, r.Method, r.URL.Path) {
-				txn = nrApp.StartTransaction(rCtx.RouteMethod + " " + rCtx.RoutePattern())
-			} else {
-				txn = nrApp.StartTransaction("NotFoundHandler")
-			}
-			defer txn.End()
-
-			w = txn.SetWebResponse(w)
-			txn.SetWebRequestHTTP(r)
-			r = newrelic.RequestWithTransactionContext(r, txn)
-
-			next.ServeHTTP(w, r)
-		})
-	}
-}