Add static HTTP file server for /.well-known/ endpoint

routers/web/web.go

@@ -350,6 +350,12 @@ func registerRoutes(m *web.Route) {
 			ctx.Redirect(setting.AppSubURL + "/user/settings/account")
 		})
 	})
+	wellKnownDir := wellKnownWebDir()
+	m.Get("/.well-known/*", func(ctx *context.Context) {
+		fsHandler := http.FileServer(wellKnownDir)
+		fs := http.StripPrefix("/.well-known/", fsHandler)
+		fs.ServeHTTP(ctx.Resp, ctx.Req)
+	})
 
 	m.Group("/explore", func() {
 		m.Get("", func(ctx *context.Context) {

routers/web/well_known.go

@@ -0,0 +1,37 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package web
+
+import (
+	"net/http"
+	"os"
+	"path/filepath"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// create or check .well-known directory exist
+func wellKnownWebDir() http.Dir {
+	wellKnownDir := http.Dir(filepath.Join(setting.CustomPath, "web-well-known"))
+	makeDirExist(string(wellKnownDir))
+
+	return wellKnownDir
+}
+
+// check directory exist, create if not
+func makeDirExist(dirName string) {
+	_, err := os.Stat(dirName)
+	if err == nil {
+		return
+	}
+	if os.IsNotExist(err) {
+		err := os.Mkdir(dirName, os.FileMode(0o755))
+		if err != nil {
+			log.Fatal(".well-known directory (%s) mkdir error %v", dirName, err)
+		}
+	} else {
+		log.Warn(".well-known directory (%s) check error %v", dirName, err)
+	}
+}