fix: rootPath support so that it uses the embedded files system (#2198)

* fix: rootPath support so that it uses the embeded files system

Signed-off-by: zachaller <zachaller@hotmail.com>

* Catch edge cases and make sure we always server index.html on not found

Signed-off-by: zachaller <zachaller@hotmail.com>

* turn path.Clean into var

Signed-off-by: zachaller <zachaller@hotmail.com>

Signed-off-by: zachaller <zachaller@hotmail.com>

server/server.go

@@ -1,13 +1,13 @@
 package server
 
 import (
-	"bufio"
 	"context"
 	"embed"
 	"fmt"
+	"io/fs"
 	"net"
 	"net/http"
-	"os"
+	"path"
 	"regexp"
 	"strings"
 	"time"
@@ -81,45 +81,11 @@ func NewServer(o ServerOptions) *ArgoRolloutsServer {
 	return &ArgoRolloutsServer{Options: o}
 }
 
-type spaFileSystem struct {
-	root http.FileSystem
-}
-
-func (fs *spaFileSystem) Open(name string) (http.File, error) {
-	f, err := fs.root.Open(name)
-	if os.IsNotExist(err) {
-		return fs.root.Open("index.html")
-	}
-	return f, err
-}
+var re = regexp.MustCompile(`<base href=".*".*/>`)
 
-//This function helps in changing base href to point to rootpath as basepath, we are making modification in only server/static/index.html file
-func withRootPath(rootpath string) {
-	inputFile, inputError := os.Open("./server/static/index.html")
-	if inputError != nil {
-		log.Error("An error occurred on opening the inputfile\n" +
-			"Does the file exist?\n" +
-			"Have you got access to it?\n")
-		panic(inputError) // exit on error
-	}
-	defer inputFile.Close()
-	inputReader := bufio.NewReader(inputFile)
-	inputString, _ := inputReader.ReadString('\n')
-	re := regexp.MustCompile(`<base href="/[^/]*/*"/>`)
-	var temp = re.ReplaceAllString(inputString, "<base href=\"/"+rootpath+"/\"/>") // href="/root/"
-
-	outputFile, _ := os.OpenFile("./server/static/index.html", os.O_TRUNC|os.O_WRONLY, 0666)
-	defer outputFile.Close()
-	outputWriter := bufio.NewWriter(outputFile)
-	outputWriter.WriteString(temp)
-	outputWriter.Flush()
-
-	//To make ui/dist/index.html file consistent with server/static/index.html
-	outputFileDist, _ := os.OpenFile("./ui/dist/app/index.html", os.O_TRUNC|os.O_WRONLY, 0666)
-	defer outputFileDist.Close()
-	outputWriterDist := bufio.NewWriter(outputFileDist)
-	outputWriterDist.WriteString(temp)
-	outputWriterDist.Flush()
+func withRootPath(fileContent []byte, rootpath string) []byte {
+	var temp = re.ReplaceAllString(string(fileContent), `<base href="`+path.Clean("/"+rootpath)+`/" />`)
+	return []byte(temp)
 }
 
 func (s *ArgoRolloutsServer) newHTTPServer(ctx context.Context, port int) *http.Server {
@@ -153,15 +119,101 @@ func (s *ArgoRolloutsServer) newHTTPServer(ctx context.Context, port int) *http.
 
 	var handler http.Handler = gwmux
 
-	withRootPath(s.Options.RootPath)
-
 	mux.Handle("/api/", handler)
 
-	mux.Handle("/"+s.Options.RootPath+"/", http.StripPrefix("/"+s.Options.RootPath+"/", http.FileServer(http.Dir("./server/static"))))
+	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		requestedURI := path.Clean(r.RequestURI)
+		rootPath := path.Clean("/" + s.Options.RootPath)
+		//If the rootPath is not in the prefix 404
+		if !strings.HasPrefix(requestedURI, rootPath) {
+			http.NotFound(w, r)
+			return
+		}
+		//If the rootPath is the requestedURI, serve index.html
+		if requestedURI == rootPath {
+			fileBytes, openErr := s.readIndexHtml()
+			if openErr != nil {
+				log.Errorf("Error opening file index.html: %v", openErr)
+				w.WriteHeader(http.StatusInternalServerError)
+				return
+			}
+			w.Write(fileBytes)
+			return
+		}
+
+		embedPath := path.Join("static", strings.TrimPrefix(requestedURI, rootPath))
+		file, openErr := static.Open(embedPath)
+		if openErr != nil {
+			fErr := openErr.(*fs.PathError)
+			//If the file is not found, serve index.html
+			if fErr.Err == fs.ErrNotExist {
+				fileBytes, openErr := s.readIndexHtml()
+				if openErr != nil {
+					log.Errorf("Error opening file index.html: %v", openErr)
+					w.WriteHeader(http.StatusInternalServerError)
+					return
+				}
+				w.Write(fileBytes)
+				return
+			} else {
+				log.Errorf("Error opening file %s: %v", embedPath, openErr)
+				w.WriteHeader(http.StatusInternalServerError)
+				return
+			}
+		}
+		defer file.Close()
+
+		stat, statErr := file.Stat()
+		if statErr != nil {
+			log.Errorf("Failed to stat file or dir %s: %v", embedPath, err)
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+
+		fileBytes := make([]byte, stat.Size())
+		_, err = file.Read(fileBytes)
+		if err != nil {
+			log.Errorf("Failed to read file %s: %v", embedPath, err)
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+
+		w.Write(fileBytes)
+	})
 
 	return &httpS
 }
 
+func (s *ArgoRolloutsServer) readIndexHtml() ([]byte, error) {
+	file, err := static.Open("static/index.html")
+	if err != nil {
+		log.Errorf("Failed to open file %s: %v", "static/index.html", err)
+		return nil, err
+	}
+	defer func() {
+		if file != nil {
+			if err := file.Close(); err != nil {
+				log.Errorf("Error closing file: %v", err)
+			}
+		}
+	}()
+
+	stat, err := file.Stat()
+	if err != nil {
+		log.Errorf("Failed to stat file or dir %s: %v", "static/index.html", err)
+		return nil, err
+	}
+
+	fileBytes := make([]byte, stat.Size())
+	_, err = file.Read(fileBytes)
+	if err != nil {
+		log.Errorf("Failed to read file %s: %v", "static/index.html", err)
+		return nil, err
+	}
+
+	return withRootPath(fileBytes, s.Options.RootPath), nil
+}
+
 func (s *ArgoRolloutsServer) newGRPCServer() *grpc.Server {
 	grpcS := grpc.NewServer()
 	var rolloutsServer rollout.RolloutServiceServer = NewServer(s.Options)