example_filesystem_test.go

Documentation: net/http

		 1  // Copyright 2018 The Go Authors. All rights reserved.
		 2  // Use of this source code is governed by a BSD-style
		 3  // license that can be found in the LICENSE file.
		 4  
		 5  package http_test
		 6  
		 7  import (
		 8  	"io/fs"
		 9  	"log"
		10  	"net/http"
		11  	"strings"
		12  )
		13  
		14  // containsDotFile reports whether name contains a path element starting with a period.
		15  // The name is assumed to be a delimited by forward slashes, as guaranteed
		16  // by the http.FileSystem interface.
		17  func containsDotFile(name string) bool {
		18  	parts := strings.Split(name, "/")
		19  	for _, part := range parts {
		20  		if strings.HasPrefix(part, ".") {
		21  			return true
		22  		}
		23  	}
		24  	return false
		25  }
		26  
		27  // dotFileHidingFile is the http.File use in dotFileHidingFileSystem.
		28  // It is used to wrap the Readdir method of http.File so that we can
		29  // remove files and directories that start with a period from its output.
		30  type dotFileHidingFile struct {
		31  	http.File
		32  }
		33  
		34  // Readdir is a wrapper around the Readdir method of the embedded File
		35  // that filters out all files that start with a period in their name.
		36  func (f dotFileHidingFile) Readdir(n int) (fis []fs.FileInfo, err error) {
		37  	files, err := f.File.Readdir(n)
		38  	for _, file := range files { // Filters out the dot files
		39  		if !strings.HasPrefix(file.Name(), ".") {
		40  			fis = append(fis, file)
		41  		}
		42  	}
		43  	return
		44  }
		45  
		46  // dotFileHidingFileSystem is an http.FileSystem that hides
		47  // hidden "dot files" from being served.
		48  type dotFileHidingFileSystem struct {
		49  	http.FileSystem
		50  }
		51  
		52  // Open is a wrapper around the Open method of the embedded FileSystem
		53  // that serves a 403 permission error when name has a file or directory
		54  // with whose name starts with a period in its path.
		55  func (fsys dotFileHidingFileSystem) Open(name string) (http.File, error) {
		56  	if containsDotFile(name) { // If dot file, return 403 response
		57  		return nil, fs.ErrPermission
		58  	}
		59  
		60  	file, err := fsys.FileSystem.Open(name)
		61  	if err != nil {
		62  		return nil, err
		63  	}
		64  	return dotFileHidingFile{file}, err
		65  }
		66  
		67  func ExampleFileServer_dotFileHiding() {
		68  	fsys := dotFileHidingFileSystem{http.Dir(".")}
		69  	http.Handle("/", http.FileServer(fsys))
		70  	log.Fatal(http.ListenAndServe(":8080", nil))
		71  }
		72
View as plain text