package middleware import ( "fmt" "html/template" "net/http" "net/url" "os" "path" "path/filepath" "strings" "github.com/labstack/echo/v4" "github.com/labstack/gommon/bytes" ) type ( // StaticConfig defines the config for Static middleware. StaticConfig struct { // Skipper defines a function to skip middleware. Skipper Skipper // Root directory from where the static content is served. // Required. Root string `yaml:"root"` // Index file for serving a directory. // Optional. Default value "index.html". Index string `yaml:"index"` // Enable HTML5 mode by forwarding all not-found requests to root so that // SPA (single-page application) can handle the routing. // Optional. Default value false. HTML5 bool `yaml:"html5"` // Enable directory browsing. // Optional. Default value false. Browse bool `yaml:"browse"` } ) const html = ` <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>{{ .Name }}</title> <style> body { font-family: Menlo, Consolas, monospace; padding: 48px; } header { padding: 4px 16px; font-size: 24px; } ul { list-style-type: none; margin: 0; padding: 20px 0 0 0; display: flex; flex-wrap: wrap; } li { width: 300px; padding: 16px; } li a { display: block; overflow: hidden; white-space: nowrap; text-overflow: ellipsis; text-decoration: none; transition: opacity 0.25s; } li span { color: #707070; font-size: 12px; } li a:hover { opacity: 0.50; } .dir { color: #E91E63; } .file { color: #673AB7; } </style> </head> <body> <header> {{ .Name }} </header> <ul> {{ range .Files }} <li> {{ if .Dir }} {{ $name := print .Name "/" }} <a class="dir" href="{{ $name }}">{{ $name }}</a> {{ else }} <a class="file" href="{{ .Name }}">{{ .Name }}</a> <span>{{ .Size }}</span> {{ end }} </li> {{ end }} </ul> </body> </html> ` var ( // DefaultStaticConfig is the default Static middleware config. DefaultStaticConfig = StaticConfig{ Skipper: DefaultSkipper, Index: "index.html", } ) // Static returns a Static middleware to serves static content from the provided // root directory. func Static(root string) echo.MiddlewareFunc { c := DefaultStaticConfig c.Root = root return StaticWithConfig(c) } // StaticWithConfig returns a Static middleware with config. // See `Static()`. func StaticWithConfig(config StaticConfig) echo.MiddlewareFunc { // Defaults if config.Root == "" { config.Root = "." // For security we want to restrict to CWD. } if config.Skipper == nil { config.Skipper = DefaultStaticConfig.Skipper } if config.Index == "" { config.Index = DefaultStaticConfig.Index } // Index template t, err := template.New("index").Parse(html) if err != nil { panic(fmt.Sprintf("echo: %v", err)) } return func(next echo.HandlerFunc) echo.HandlerFunc { return func(c echo.Context) (err error) { if config.Skipper(c) { return next(c) } p := c.Request().URL.Path if strings.HasSuffix(c.Path(), "*") { // When serving from a group, e.g. `/static*`. p = c.Param("*") } p, err = url.PathUnescape(p) if err != nil { return } name := filepath.Join(config.Root, path.Clean("/"+p)) // "/"+ for security fi, err := os.Stat(name) if err != nil { if os.IsNotExist(err) { if err = next(c); err != nil { if he, ok := err.(*echo.HTTPError); ok { if config.HTML5 && he.Code == http.StatusNotFound { return c.File(filepath.Join(config.Root, config.Index)) } } return } } return } if fi.IsDir() { index := filepath.Join(name, config.Index) fi, err = os.Stat(index) if err != nil { if config.Browse { return listDir(t, name, c.Response()) } if os.IsNotExist(err) { return next(c) } return } return c.File(index) } return c.File(name) } } } func listDir(t *template.Template, name string, res *echo.Response) (err error) { file, err := os.Open(name) if err != nil { return } files, err := file.Readdir(-1) if err != nil { return } // Create directory index res.Header().Set(echo.HeaderContentType, echo.MIMETextHTMLCharsetUTF8) data := struct { Name string Files []interface{} }{ Name: name, } for _, f := range files { data.Files = append(data.Files, struct { Name string Dir bool Size string }{f.Name(), f.IsDir(), bytes.Format(f.Size())}) } return t.Execute(res, data) }