Serving Static Files using GoFr

Often, we are required to serve static content such as a default profile image, a favicon, or a background image for our web application. We want to have a mechanism to serve that static content without the hassle of implementing it from scratch.

GoFr provides a default mechanism where if a static folder is available in the directory of the application, it automatically provides an endpoint with /static/<filename>, here filename refers to the file we want to get static content to be served.

The endpoint's root — /static — serves that folder's index.html, as does the root of any subdirectory beneath it (/static/docs serves static/docs/index.html). A directory without an index.html returns 404 rather than a listing of its contents, so nothing is disclosed that was not deliberately published; if the served folder has a 404.html, that page is returned as the body.

Every one of these forms is answered with the file itself — /static, /static/, and /static/index.html all return the same page, and none of them redirects.

Because /static is answered directly rather than redirected to /static/, a relative URL in a page served at the endpoint root resolves against the parent path: `` requests /logo.png from /static and /static/logo.png from /static/. HTML served at an endpoint root should use root-relative URLs (/static/logo.png) or declare a <base href="/static/">.

Only GET and HEAD are served. Any other method returns 405 with an Allow: GET, HEAD header. A file the process cannot read returns 403.

Only regular files are served. A path that resolves to anything else — a directory, a named pipe — is treated as not found, and an openapi.json in a served folder returns 403 in any capitalization; the API specification is reachable only through /.well-known/swagger and /.well-known/openapi.json.

Example project structure:

project_folder
|
|---configs
|       .env
|---static
|       img1.jpeg
|       img2.png
|       img3.jpeg
|   main.go
|   main_test.go

main.go code:

package main

import "gofr.dev/pkg/gofr"

func main() {
	app := gofr.New()
	app.Run()
}

Additionally, if we want to serve more static endpoints, we have a dedicated function called AddStaticFiles() which takes 2 parameters endpoint and the filepath of the static folder which we want to serve. If the folder contains a 404.html file, GoFr returns that page as the body of any "Not Found" response. The filepath must be a directory; anything else is refused at registration and the endpoint is not served.

Example project structure:

project_folder
|
|---configs
|       .env
|---static
|       img1.jpeg
|       img2.png
|       img3.jpeg
|---public
|       |---css
|       |       main.css
|       |---js
|       |       main.js
|       |   index.html
|       |   404.html
|   main.go
|   main_test.go

main.go file:

package main

import "gofr.dev/pkg/gofr"

func main() {
	app := gofr.New()
	app.AddStaticFiles("public", "./public")
	app.Run()
}

In the above example, both endpoints /public and /static are available for the app to render the static content. /public serves public/index.html, while /static — whose folder has no index.html — returns 404.