clash api: download clash-dashboard if external-ui directory is empty

experimental/clashapi/server.go

@@ -47,6 +47,10 @@ type Server struct {
 	storeFakeIP    bool
 	cacheFilePath  string
 	cacheFile      adapter.ClashCacheFile
+
+	externalUI               string
+	externalUIDownloadURL    string
+	externalUIDownloadDetour string
 }
 
 func NewServer(router adapter.Router, logFactory log.ObservableFactory, options option.ClashAPIOptions) (adapter.ClashServer, error) {
@@ -59,11 +63,13 @@ func NewServer(router adapter.Router, logFactory log.ObservableFactory, options
 			Addr:    options.ExternalController,
 			Handler: chiRouter,
 		},
-		trafficManager: trafficManager,
-		urlTestHistory: urltest.NewHistoryStorage(),
-		mode:           strings.ToLower(options.DefaultMode),
-		storeSelected:  options.StoreSelected,
-		storeFakeIP:    options.StoreFakeIP,
+		trafficManager:           trafficManager,
+		urlTestHistory:           urltest.NewHistoryStorage(),
+		mode:                     strings.ToLower(options.DefaultMode),
+		storeSelected:            options.StoreSelected,
+		storeFakeIP:              options.StoreFakeIP,
+		externalUIDownloadURL:    options.ExternalUIDownloadURL,
+		externalUIDownloadDetour: options.ExternalUIDownloadDetour,
 	}
 	if server.mode == "" {
 		server.mode = "rule"
@@ -105,8 +111,9 @@ func NewServer(router adapter.Router, logFactory log.ObservableFactory, options
 		r.Mount("/dns", dnsRouter(router))
 	})
 	if options.ExternalUI != "" {
+		server.externalUI = C.BasePath(os.ExpandEnv(options.ExternalUI))
 		chiRouter.Group(func(r chi.Router) {
-			fs := http.StripPrefix("/ui", http.FileServer(http.Dir(C.BasePath(os.ExpandEnv(options.ExternalUI)))))
+			fs := http.StripPrefix("/ui", http.FileServer(http.Dir(server.externalUI)))
 			r.Get("/ui", http.RedirectHandler("/ui/", http.StatusTemporaryRedirect).ServeHTTP)
 			r.Get("/ui/*", func(w http.ResponseWriter, r *http.Request) {
 				fs.ServeHTTP(w, r)
@@ -128,6 +135,7 @@ func (s *Server) PreStart() error {
 }
 
 func (s *Server) Start() error {
+	s.checkAndDownloadExternalUI()
 	listener, err := net.Listen("tcp", s.httpServer.Addr)
 	if err != nil {
 		return E.Cause(err, "external controller listen error")

experimental/clashapi/server_resources.go

@@ -0,0 +1,164 @@
+package clashapi
+
+import (
+	"archive/zip"
+	"context"
+	"io"
+	"net"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func (s *Server) checkAndDownloadExternalUI() {
+	if s.externalUI == "" {
+		return
+	}
+	entries, err := os.ReadDir(s.externalUI)
+	if err != nil {
+		os.MkdirAll(s.externalUI, 0o755)
+	}
+	if len(entries) == 0 {
+		err = s.downloadExternalUI()
+		if err != nil {
+			s.logger.Error("download external ui error: ", err)
+		}
+	}
+}
+
+func (s *Server) downloadExternalUI() error {
+	var downloadURL string
+	if s.externalUIDownloadURL != "" {
+		downloadURL = s.externalUIDownloadURL
+	} else {
+		downloadURL = "https://github.com/Dreamacro/clash-dashboard/archive/refs/heads/gh-pages.zip"
+	}
+	s.logger.Info("downloading external ui")
+	var detour adapter.Outbound
+	if s.externalUIDownloadDetour != "" {
+		outbound, loaded := s.router.Outbound(s.externalUIDownloadDetour)
+		if !loaded {
+			return E.New("detour outbound not found: ", s.externalUIDownloadDetour)
+		}
+		detour = outbound
+	} else {
+		detour = s.router.DefaultOutbound(N.NetworkTCP)
+	}
+	httpClient := &http.Client{
+		Transport: &http.Transport{
+			ForceAttemptHTTP2:   true,
+			TLSHandshakeTimeout: 5 * time.Second,
+			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				return detour.DialContext(ctx, network, M.ParseSocksaddr(addr))
+			},
+		},
+	}
+	defer httpClient.CloseIdleConnections()
+	response, err := httpClient.Get(downloadURL)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode != http.StatusOK {
+		return E.New("download external ui failed: ", response.Status)
+	}
+	err = s.downloadZIP(filepath.Base(downloadURL), response.Body, s.externalUI)
+	if err != nil {
+		removeAllInDirectory(s.externalUI)
+	}
+	return err
+}
+
+func (s *Server) downloadZIP(name string, body io.Reader, output string) error {
+	tempFile, err := C.CreateTemp(name)
+	if err != nil {
+		return err
+	}
+	defer os.Remove(tempFile.Name())
+	_, err = io.Copy(tempFile, body)
+	tempFile.Close()
+	if err != nil {
+		return err
+	}
+	reader, err := zip.OpenReader(tempFile.Name())
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+	trimDir := zipIsInSingleDirectory(reader.File)
+	for _, file := range reader.File {
+		if file.FileInfo().IsDir() {
+			continue
+		}
+		pathElements := strings.Split(file.Name, "/")
+		if trimDir {
+			pathElements = pathElements[1:]
+		}
+		saveDirectory := output
+		if len(pathElements) > 1 {
+			saveDirectory = filepath.Join(saveDirectory, filepath.Join(pathElements[:len(pathElements)-1]...))
+		}
+		err = os.MkdirAll(saveDirectory, 0o755)
+		if err != nil {
+			return err
+		}
+		savePath := filepath.Join(saveDirectory, pathElements[len(pathElements)-1])
+		err = downloadZIPEntry(file, savePath)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func downloadZIPEntry(zipFile *zip.File, savePath string) error {
+	saveFile, err := os.Create(savePath)
+	if err != nil {
+		return err
+	}
+	defer saveFile.Close()
+	reader, err := zipFile.Open()
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+	return common.Error(io.Copy(saveFile, reader))
+}
+
+func removeAllInDirectory(directory string) {
+	dirEntries, err := os.ReadDir(directory)
+	if err != nil {
+		return
+	}
+	for _, dirEntry := range dirEntries {
+		os.RemoveAll(filepath.Join(directory, dirEntry.Name()))
+	}
+}
+
+func zipIsInSingleDirectory(files []*zip.File) bool {
+	var singleDirectory string
+	for _, file := range files {
+		if file.FileInfo().IsDir() {
+			continue
+		}
+		pathElements := strings.Split(file.Name, "/")
+		if len(pathElements) == 0 {
+			return false
+		}
+		if singleDirectory == "" {
+			singleDirectory = pathElements[0]
+		} else if singleDirectory != pathElements[0] {
+			return false
+		}
+	}
+	return true
+}