How to server static files with virtual hosts functioality in Go

huangapple
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英文:

How to server static files with virtual hosts functioality in Go

问题

如何在Go中为虚拟主机提供静态文件（使用FileServer）？

如果我有自己的处理函数，这个任务似乎很容易解决[1]：

  1. package main
  3. import (
  4.     "fmt"
  5.     "net/http"
  6. )
  8. func main() {
  9.     http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
  10.         fmt.Fprintf(w, "Hello, world!")
  11.     })
  12.     http.HandleFunc("qa.example.com/", func(w http.ResponseWriter, r *http.Request) {
  13.         fmt.Fprintf(w, "Hello, improved world!")
  14.     })
  15.     http.ListenAndServe(":8080", nil)
  16. }

但是，如果我需要为虚拟主机提供静态文件（使用FileServer），该怎么办？

这个代码片段：

  1. r.PathPrefix("qa.example.com/").Handler(http.FileServer(http.Dir("/static/qa/")))

不起作用 - 它被忽略了。

我做错了什么？
这种方法一般是错误的吗？

英文:

How can I server static files (with FileServer) for a virtual host in Go?

If I have my own handler function, the task seems to be easily solvable [1]:

  1. package main
  3. import (
  4.     "fmt"
  5.     "net/http"
  6. )
  8. func main() {
  9.     http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
  10.         fmt.Fprintf(w, "Hello, world!")
  11.     })
  12.     http.HandleFunc("qa.example.com/", func(w http.ResponseWriter, r *http.Request) {
  13.         fmt.Fprintf(w, "Hello, improved world!")
  14.     })
  15.     http.ListenAndServe(":8080", nil)
  16. }

But what if I need to serve static files (with FileServer)
for a virtual host?

This

  1. r.PathPrefix("qa.example.com/").Handler(http.FileServer(http.Dir("/static/qa/")))

does not work — it is just ignored.

What am I doing wrong?
Is this approach generally wrong?

答案1

得分: 2

  1. package main
  3. import (
  4. 	"embed"
  5. 	"fmt"
  6. 	"net/http"
  7. 	"strings"
  8. 	"time"
  9. )
  11. //go:embed *.go
  12. var f embed.FS
  14. func main() {
  15. 	// embed.Fs默认使用当前时间或环境变量作为默认修改时间。
  16. 	now := time.Now()
  17. 	// 使用主机名映射到http.FileSystem
  18. 	vhosts := make(map[string]http.FileSystem)
  19. 	vhosts["qa.example.com"] = http.FS(f)    // 来自embed.FS
  20. 	vhosts["my.example.com"] = http.Dir(".") // 来自http.Dir
  22. 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
  23. 		fmt.Fprintf(w, "Hello, world!")
  24. 	})
  25. 	http.HandleFunc("/static/", func(w http.ResponseWriter, r *http.Request) {
  26. 		// 查找主机
  27. 		fs, ok := vhosts[r.Host]
  28. 		if !ok {
  29. 			w.WriteHeader(404)
  30. 			w.Write([]byte("404 not found vhost"))
  31. 			return
  32. 		}
  33. 		// 从http.FileSystem打开文件
  34. 		file, err := fs.Open(strings.TrimPrefix(r.URL.Path, "/static/"))
  35. 		if err != nil {
  36. 			// 参考go1.18.3/net/http/fs.go中的toHTTPError函数处理文件错误。
  37. 			w.Write([]byte("检查错误是否为403、404或500"))
  38. 			return
  39. 		}
  40. 		stat, _ := file.Stat()
  41. 		// 修复embed修改时间为零的问题。
  42. 		modtime := stat.ModTime()
  43. 		if modtime.IsZero() {
  44. 			modtime = now
  45. 		}
  46. 		// 响应
  47. 		http.ServeContent(w, r, stat.Name(), modtime, file)
  49. 	})
  51. 	http.ListenAndServe(":8080", nil)
  52. }

运行测试执行命令 curl -H "Host: my.example.com" 127.0.0.1:8080/static/01.go，将 01.go 替换为你的静态文件名。

英文: 
  1. package main
  3. import (
  4. 	"embed"
  5. 	"fmt"
  6. 	"net/http"
  7. 	"strings"
  8. 	"time"
  9. )
  11. //go:embed *.go
  12. var f embed.FS
  14. func main() {
  15. 	// embed.Fs defaule modtime use now or env value.
  16. 	now := time.Now()
  17. 	// use mapping host to http.FileSystem
  18. 	vhosts := make(map[string]http.FileSystem)
  19. 	vhosts["qa.example.com"] = http.FS(f)    // from embed.FS
  20. 	vhosts["my.example.com"] = http.Dir(".") // from http.Dir
  22. 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
  23. 		fmt.Fprintf(w, "Hello, world!")
  24. 	})
  25. 	http.HandleFunc("/static/", func(w http.ResponseWriter, r *http.Request) {
  26. 		// find host
  27. 		fs, ok := vhosts[r.Host]
  28. 		if !ok {
  29. 			w.WriteHeader(404)
  30. 			w.Write([]byte("404 not found vhost"))
  31. 			return
  32. 		}
  33. 		// open file from http.FileSystem
  34. 		file, err := fs.Open(strings.TrimPrefix(r.URL.Path, "/static/"))
  35. 		if err != nil {
  36. 			// reference go1.18.3/net/http/fs.go toHTTPError function hander file error.
  37. 			w.Write([]byte("check err is 403 or 404 or 500"))
  38. 			return
  39. 		}
  40. 		stat, _ := file.Stat()
  41. 		// fix embed modtime is zero.
  42. 		modtime := stat.ModTime()
  43. 		if modtime.IsZero() {
  44. 			modtime = now
  45. 		}
  46. 		// response
  47. 		http.ServeContent(w, r, stat.Name(), modtime, file)
  49. 	})
  51. 	http.ListenAndServe(":8080", nil)
  52. }

run test exec command curl -H "Host: my.example.com" 127.0.0.1:8080/static/01.go, 01.go replacte your static filename.

答案2

得分: 0

为host/path注册一个处理程序。仅在调用文件处理程序时去除/path部分。

此注册将从目录./static/qa/为qa.example.com/static/*提供文件服务。

  1. http.HandleFunc("qa.example.com/static/", http.StripPrefix("/static", http.FileServer(http.Dir("./static/qa/"))))
英文:

Register a handler for host/path. Strip the /path part only when invoking the file handler.

This registration serves files for qa.example.com/static/* from the directory ./static/qa/.

  1. http.HandleFunc("qa.example.com/static/", http.StripPrefix("/static", http.FileServer(http.Dir("./static/qa/")))

huangapple
  • 本文由 发表于 2022年6月13日 05:48:42
  • 转载请务必保留本文链接：https://go.coder-hub.com/72596134.html
  • go
  • http
  • virtualhost
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