feat: support using external dist files (close #5531)

internal/conf/config.go

@@ -49,6 +49,7 @@ type Config struct {
 	Scheme                Scheme    `json:"scheme"`
 	TempDir               string    `json:"temp_dir" env:"TEMP_DIR"`
 	BleveDir              string    `json:"bleve_dir" env:"BLEVE_DIR"`
+	DistDir               string    `json:"dist_dir"`
 	Log                   LogConfig `json:"log"`
 	DelayedStart          int       `json:"delayed_start" env:"DELAYED_START"`
 	MaxConnections        int       `json:"max_connections" env:"MAX_CONNECTIONS"`

server/static/static.go

@@ -3,25 +3,48 @@ package static
 import (
 	"errors"
 	"fmt"
+	"github.com/alist-org/alist/v3/public"
+	"io"
 	"io/fs"
 	"net/http"
+	"os"
 	"strings"
 
 	"github.com/alist-org/alist/v3/internal/conf"
 	"github.com/alist-org/alist/v3/internal/setting"
 	"github.com/alist-org/alist/v3/pkg/utils"
-	"github.com/alist-org/alist/v3/public"
 	"github.com/gin-gonic/gin"
 )
 
-func InitIndex() {
-	index, err := public.Public.ReadFile("dist/index.html")
+var static fs.FS = public.Public
+
+func initStatic() {
+	if conf.Conf.DistDir == "" {
+		dist, err := fs.Sub(static, "dist")
+		if err != nil {
+			utils.Log.Fatalf("failed to read dist dir")
+		}
+		static = dist
+		return
+	}
+	static = os.DirFS(conf.Conf.DistDir)
+}
+
+func initIndex() {
+	indexFile, err := static.Open("index.html")
 	if err != nil {
 		if errors.Is(err, fs.ErrNotExist) {
 			utils.Log.Fatalf("index.html not exist, you may forget to put dist of frontend to public/dist")
 		}
 		utils.Log.Fatalf("failed to read index.html: %v", err)
 	}
+	defer func() {
+		_ = indexFile.Close()
+	}()
+	index, err := io.ReadAll(indexFile)
+	if err != nil {
+		utils.Log.Fatalf("failed to read dist/index.html")
+	}
 	conf.RawIndexHtml = string(index)
 	siteConfig := getSiteConfig()
 	replaceMap := map[string]string{
@@ -60,7 +83,8 @@ func UpdateIndex() {
 }
 
 func Static(r *gin.RouterGroup, noRoute func(handlers ...gin.HandlerFunc)) {
-	InitIndex()
+	initStatic()
+	initIndex()
 	folders := []string{"assets", "images", "streamer", "static"}
 	r.Use(func(c *gin.Context) {
 		for i := range folders {
@@ -70,8 +94,7 @@ func Static(r *gin.RouterGroup, noRoute func(handlers ...gin.HandlerFunc)) {
 		}
 	})
 	for i, folder := range folders {
-		folder = "dist/" + folder
-		sub, err := fs.Sub(public.Public, folder)
+		sub, err := fs.Sub(static, folder)
 		if err != nil {
 			utils.Log.Fatalf("can't find folder: %s", folder)
 		}