Static fileserver improvements, optional admin panel route (#100)

* better asset serving, optional admin panel route

* linting

internal/router/router.go

@@ -46,6 +46,8 @@ type Router interface {
 	AttachMiddleware(handler gin.HandlerFunc)
 	// Attach 404 NoRoute handler
 	AttachNoRouteHandler(handler gin.HandlerFunc)
+	// Add Gin StaticFile handler
+	AttachStaticFS(relativePath string, fs http.FileSystem)
 	// Start the router
 	Start()
 	// Stop the router
@@ -61,6 +63,11 @@ type router struct {
 	certManager *autocert.Manager
 }
 
+// Add Gin StaticFile handler
+func (r *router) AttachStaticFS(relativePath string, fs http.FileSystem) {
+	r.engine.StaticFS(relativePath, fs)
+}
+
 // Start starts the router nicely.
 //
 // Different ports and handlers will be served depending on whether letsencrypt is enabled or not.

internal/web/base.go

@@ -24,7 +24,6 @@
 	"os"
 	"path/filepath"
 
-	"github.com/gin-contrib/static"
 	"github.com/gin-gonic/gin"
 	"github.com/sirupsen/logrus"
 	"github.com/superseriousbusiness/gotosocial/internal/api"
@@ -93,7 +92,11 @@ func (m *Module) Route(s router.Router) error {
 		return fmt.Errorf("error getting current working directory: %s", err)
 	}
 	assetPath := filepath.Join(cwd, m.config.TemplateConfig.AssetBaseDir)
-	s.AttachMiddleware(static.Serve("/assets", static.LocalFile(assetPath, false)))
+	s.AttachStaticFS("/assets", FileSystem{http.Dir(assetPath)})
+
+	// Admin panel route, if it exists
+	adminPath := filepath.Join(cwd, m.config.TemplateConfig.AssetBaseDir, "/admin")
+	s.AttachStaticFS("/admin", FileSystem{http.Dir(adminPath)})
 
 	// serve front-page
 	s.AttachHandler(http.MethodGet, "/", m.baseHandler)
@@ -101,9 +104,5 @@ func (m *Module) Route(s router.Router) error {
 	// 404 handler
 	s.AttachNoRouteHandler(m.NotFoundHandler)
 
-	if err != nil {
-		return fmt.Errorf("error setting router FuncMap: %s", err)
-	}
-
 	return nil
 }

internal/web/fileserver.go

@@ -0,0 +1,47 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package web
+
+import (
+	"net/http"
+	"strings"
+)
+
+type FileSystem struct {
+	fs http.FileSystem
+}
+
+// FileSystem server that only accepts directory listings when an index.html is available
+// from https://gist.github.com/hauxe/f2ea1901216177ccf9550a1b8bd59178
+func (fs FileSystem) Open(path string) (http.File, error) {
+	f, err := fs.fs.Open(path)
+	if err != nil {
+		return nil, err
+	}
+
+	s, _ := f.Stat()
+	if s.IsDir() {
+		index := strings.TrimSuffix(path, "/") + "/index.html"
+		if _, err := fs.fs.Open(index); err != nil {
+			return nil, err
+		}
+	}
+
+	return f, nil
+}