fix #1 . add request ID middleware (#3)

* fix #1 . add request ID middleware

constants/constants.go

@@ -13,5 +13,6 @@ const (
 	LogKeyURLPath          = "_url_path"
 	LogKeyUserAgent        = "_user_agent"
 	LogKeyResquestDuration = "_request_duration_ms"
+	LogKeyResquestID       = "_request_id"
 	LogKeyHTTPStatus       = "_http_status"
 )

go.mod

@@ -3,6 +3,7 @@ module github.com/AndersonQ/go-skeleton
 require (
 	github.com/caarlos0/env v3.5.0+incompatible
 	github.com/go-chi/chi v4.0.2+incompatible
+	github.com/google/uuid v1.1.1
 	github.com/newrelic/go-agent v2.7.0+incompatible
 	github.com/rs/zerolog v1.14.3
 	github.com/stretchr/testify v1.3.0 // indirect

go.sum

@@ -5,6 +5,8 @@ github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-chi/chi v4.0.2+incompatible h1:maB6vn6FqCxrpz4FqWdh4+lwpyZIQS7YEAUcHlgXVRs=
 github.com/go-chi/chi v4.0.2+incompatible/go.mod h1:eB3wogJHnLi3x/kFX2A+IbTBlXxmMeXJVKy9tTv1XzQ=
+github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
+github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/newrelic/go-agent v2.7.0+incompatible h1:T5tJ9nNY1bXBfLUTCEZRuBLPT0f9+mE1jd4EaNoN5Zs=
 github.com/newrelic/go-agent v2.7.0+incompatible/go.mod h1:a8Fv1b/fYhFSReoTU6HDkTYIMZeSVNffmoS726Y0LzQ=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=

main.go

@@ -68,7 +68,7 @@ func main() {
 
 func initRouter(cfg config.Config, newrelicApp newrelic.Application, logger zerolog.Logger) *chi.Mux {
 	router := chi.NewRouter()
-	// TODO(Anderson): create a tracking ID middleware
+	router.Use(middlewares.RequestIDHandler)
 	router.Use(hlog.NewHandler(logger))
 	router.Use(middleware.StripSlashes)
 	router.Use(middleware.Compress(flate.BestSpeed))

middlewares/middlewares.go

@@ -25,12 +25,12 @@ func RequestLogWrapper(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		// TODO: Use a clock abstraction instead of time.Now()
 		startTime := time.Now()
-
 		logger := zerolog.Ctx(r.Context()).With().
 			Str(constants.LogKeyHTTPMethod, r.Method).
 			Str(constants.LogKeyURLPath, r.URL.Path).
 			Str(constants.LogKeyUserAgent, r.UserAgent()).
 			Str(constants.LogKeyRemoteAddr, r.RemoteAddr).
+			Str(constants.LogKeyResquestID, requestIDFromContext(r.Context())).
 			Logger()
 
 		ww := statusResponseWriter{w: w}

middlewares/request_id.go

@@ -0,0 +1,41 @@
+package middlewares
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/google/uuid"
+)
+
+type reqIDCtx int
+
+const reqIDContexKey reqIDCtx = reqIDCtx(0)
+
+// requestIDContext creates a context with request id
+func requestIDContext(ctx context.Context, rid string) context.Context {
+	return context.WithValue(ctx, reqIDContexKey, rid)
+}
+
+// requestIDFromContext returns the request id from context
+func requestIDFromContext(ctx context.Context) string {
+	rid, ok := ctx.Value(reqIDContexKey).(string)
+	if !ok {
+		return ""
+	}
+	return rid
+}
+
+// RequestIDHandler sets unique request id.
+// If header `X-Request-ID` is already present in the request, that is considered the
+// request id. Otherwise, generates a new unique ID.
+func RequestIDHandler(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		rid := r.Header.Get("X-Request-ID")
+		if rid == "" {
+			rid = uuid.New().String()
+			r.Header.Set("X-Request-ID", rid)
+		}
+		ctx := requestIDContext(r.Context(), rid)
+		h.ServeHTTP(w, r.WithContext(ctx))
+	})
+}