remove NewStaticContentHandlerFunc

cmd/asynqmon/main.go

@@ -5,6 +5,7 @@ import (
 	"embed"
 	"flag"
 	"fmt"
+	"github.com/gorilla/mux"
 	"log"
 	"net/http"
 	"strings"
@@ -107,21 +108,25 @@ func main() {
 
 	h := asynqmon.New(asynqmon.Options{
 		RedisConnOpt: redisConnOpt,
-		Middlewares:  []asynqmon.MiddlewareFunc{loggingMiddleware},
-		StaticContentHandler: asynqmon.NewStaticContentHandler(
-			staticContents,
-			"ui-assets",
-			"index.html",
-		),
 	})
 	defer h.Close()
 
+	r := mux.NewRouter()
+	r.PathPrefix("/api").Handler(h)
+	r.PathPrefix("/").Handler(&staticContentHandler{
+		contents:      staticContents,
+		staticDirPath: "ui-assets",
+		indexFileName: "index.html",
+	})
+
+	r.Use(loggingMiddleware)
+
 	c := cors.New(cors.Options{
 		AllowedMethods: []string{"GET", "POST", "DELETE"},
 	})
 
 	srv := &http.Server{
-		Handler:      c.Handler(h),
+		Handler:      c.Handler(r),
 		Addr:         fmt.Sprintf(":%d", flagPort),
 		WriteTimeout: 10 * time.Second,
 		ReadTimeout:  10 * time.Second,

cmd/asynqmon/static.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"embed"
+	"errors"
+	"io/fs"
+	"net/http"
+	"path/filepath"
+)
+
+// staticFileServer implements the http.Handler interface, so we can use it
+// to respond to HTTP requests. The path to the static directory and
+// path to the index file within that static directory are used to
+// serve the SPA in the given static directory.
+type staticContentHandler struct {
+	contents      embed.FS
+	staticDirPath string
+	indexFileName string
+}
+
+// ServeHTTP inspects the URL path to locate a file within the static dir
+// on the SPA handler.
+// If path '/' is requested, it will serve the index file, otherwise it will
+// serve the file specified by the URL path.
+func (h *staticContentHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	// Get the absolute path to prevent directory traversal.
+	path, err := filepath.Abs(r.URL.Path)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	if path == "/" {
+		path = h.indexFilePath()
+	} else {
+		path = filepath.Join(h.staticDirPath, path)
+	}
+
+	bytes, err := h.contents.ReadFile(path)
+	// If path is error (e.g. file not exist, path is a directory), serve index file.
+	var pathErr *fs.PathError
+	if errors.As(err, &pathErr) {
+		bytes, err = h.contents.ReadFile(h.indexFilePath())
+	}
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	if _, err := w.Write(bytes); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+}
+
+func (h *staticContentHandler) indexFilePath() string {
+	return filepath.Join(h.staticDirPath, h.indexFileName)
+}