use go 1.12

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

vendor/github.com/mholt/caddy/caddyhttp/root/root.go

@@ -0,0 +1,66 @@
+// 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 root
+
+import (
+	"log"
+	"os"
+
+	"github.com/mholt/caddy"
+	"github.com/mholt/caddy/caddyhttp/httpserver"
+)
+
+func init() {
+	caddy.RegisterPlugin("root", caddy.Plugin{
+		ServerType: "http",
+		Action:     setupRoot,
+	})
+}
+
+func setupRoot(c *caddy.Controller) error {
+	config := httpserver.GetConfig(c)
+
+	for c.Next() {
+		if !c.NextArg() {
+			return c.ArgErr()
+		}
+		config.Root = c.Val()
+		if c.NextArg() {
+			// only one argument allowed
+			return c.ArgErr()
+		}
+	}
+	//first check that the path is not a symlink, os.Stat panics when this is true
+	info, _ := os.Lstat(config.Root)
+	if info != nil && info.Mode()&os.ModeSymlink == os.ModeSymlink {
+		//just print out info, delegate responsibility for symlink validity to
+		//underlying Go framework, no need to test / verify twice
+		log.Printf("[INFO] Root path is symlink: %s", config.Root)
+	} else {
+		// Check if root path exists
+		_, err := os.Stat(config.Root)
+		if err != nil {
+			if os.IsNotExist(err) {
+				// Allow this, because the folder might appear later.
+				// But make sure the user knows!
+				log.Printf("[WARNING] Root path does not exist: %s", config.Root)
+			} else {
+				return c.Errf("Unable to access root path '%s': %v", config.Root, err)
+			}
+		}
+	}
+
+	return nil
+}