Static Files

Serve a folder of assets with one call. Zinc answers GET and HEAD, sets content types, supports Range and conditional requests through http.ServeContent, and rejects paths that try to escape the folder.

if err := app.Static("/assets", "./public"); err != nil {
  log.Fatal(err)
}

GET /assets/css/app.css now serves ./public/css/app.css. A directory that does not exist is not detected until a request arrives, so check the path at startup if a wrong deploy path should stop the process.

Zinc opens one confined directory handle on the first file request and retains it for later requests. Symlinks remain inside that directory. If you rename or replace the directory after the first request, the mount continues to serve the original directory until the app is recreated. Use StaticFS with a filesystem you manage if assets must switch without restarting. app.Shutdown(ctx) releases the handle after requests drain. If another http.Server serves the app as an http.Handler, call app.Close() after that server stops to release the handle. StaticFS uses the filesystem you supply; you retain ownership of it.

A single file

if err := app.File("/robots.txt", "./public/robots.txt"); err != nil {
  log.Fatal(err)
}

Embedded assets

Compile assets into the binary with embed, then serve any fs.FS:

//go:embed public
var public embed.FS

func main() {
  app := zinc.New()

  assets, err := fs.Sub(public, "public")
  if err != nil {
    log.Fatal(err)
  }
  if err := app.StaticFS("/assets", assets); err != nil {
    log.Fatal(err)
  }
  if err := app.FileFS("/favicon.ico", "favicon.ico", assets); err != nil {
    log.Fatal(err)
  }

  log.Fatal(app.Listen(":8080"))
}

fs.Sub strips the public/ prefix so URLs do not include it. The Embed Resources recipe has a runnable version.

Index files and directory listings

err := app.Static("/docs", "./site",
  zinc.WithStaticIndex("home.html"),  // served for directory requests; default "index.html"
  zinc.WithStaticBrowse(true),        // list files when there is no index
)

Directory listing is off by default. Turn it on only for content you intend to publish.

Existing file servers

A standard http.FileServer, or any other handler, can own a path instead:

app.Mount("/files", http.FileServer(http.Dir("./shared"))) // Mount strips "/files" itself

Prefer Static and StaticFS in new code. They reject methods other than GET and HEAD, never list directories unless asked, and serve an index file by default.

Static middleware

The Static middleware serves files from app.Use and falls through to your routes when a file does not exist. It suits apps where files and routes share the same paths.

Next steps

• Embed Resources ships a single binary with its assets.
• Responses and Rendering sends individual files from handlers.