use go 1.12

Signed-off-by: hongming <talonwan@yunify.com>

vendor/github.com/mholt/caddy/caddyhttp/extensions/ext.go

@@ -0,0 +1,58 @@
+// Copyright 2015 Light Code Labs, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package extensions contains middleware for clean URLs.
+//
+// The root path of the site is passed in as well as possible extensions
+// to try internally for paths requested that don't match an existing
+// resource. The first path+ext combination that matches a valid file
+// will be used.
+package extensions
+
+import (
+	"net/http"
+	"os"
+	"path"
+	"strings"
+
+	"github.com/mholt/caddy/caddyhttp/httpserver"
+)
+
+// Ext can assume an extension from clean URLs.
+// It tries extensions in the order listed in Extensions.
+type Ext struct {
+	// Next handler in the chain
+	Next httpserver.Handler
+
+	// Path to site root
+	Root string
+
+	// List of extensions to try
+	Extensions []string
+}
+
+// ServeHTTP implements the httpserver.Handler interface.
+func (e Ext) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
+	urlpath := strings.TrimSuffix(r.URL.Path, "/")
+	if len(r.URL.Path) > 0 && path.Ext(urlpath) == "" && r.URL.Path[len(r.URL.Path)-1] != '/' {
+		for _, ext := range e.Extensions {
+			_, err := os.Stat(httpserver.SafePath(e.Root, urlpath) + ext)
+			if err == nil {
+				r.URL.Path = urlpath + ext
+				break
+			}
+		}
+	}
+	return e.Next.ServeHTTP(w, r)
+}