Fiber: 🐛 directory need auto redirect

[suntong]

Fiber version
v1.11.1 & v1.13.3

Code snippet

Take a look at
https://github.com/suntong/fiber_demo/blob/master/app/static-gz.go

Issue description

The results of visiting

• http://localhost:3000/sample0
• http://localhost:3000/sample1
• http://localhost:3000/sample-gz

are wrong, while visiting the following are right:

• http://localhost:3000/sample0/
• http://localhost:3000/sample1/
• http://localhost:3000/sample-gz/

Normal web servers would redirect http://site/directory to http://site/directory/ automatically (note the extra trailing /), so they would not exhibit such differences. I think so should fiber too.

[thomasvvugt]

Hi @suntong,
Fiber has a setting called StrictRouting to change it's behavior to treat /foo and /foo/ as the same.
Redirecting /foo to /foo/ would require you to write a middleware to check for the trailing /, and redirect the client if it's not present.
To my knowledge, there are no such guidelines to specifically use/not use a trailing / for a URL.

[suntong]

Thanks for your reply @thomasvvugt, so I took a look and found that StrictRouting would actually _remove_ the trailing slashes, which would actually make things worse and not working any more.

Maybe there is no obvious guidelines, but if you take a look at every web server, the above described behaviors are what they actually doing. So maybe it is such a common sense that there is no need for a written guidelines for it.

OK. I'll write a middleware on my own, and submit a PR against this issue.

Thanks

[thomasvvugt]

Hi @suntong,

By default, StrictRouting is disabled. When StrictRouting is enabled, it will indeed redirect the client if it requests a route with any trailing slashes (/).
So we can take advantage of Fiber's default behavior by using a simple middleware which does the job of redirecting the client if there are no trailing slashes present in the original URL. I also took note of the fact that clients can also request files with file extensions.
Take a look at my example below, and let me know if that helps you out!

package main

import (
    "log"
    "regexp"
    "strings"

    "github.com/gofiber/fiber"
    "github.com/gofiber/utils"
)

func main() {
    app := fiber.New(&fiber.Settings{
        // By default -> StrictRouting: false,
    })

    // Custom middleware to redirect routes with a trailing `/`
    app.Use(func(c *fiber.Ctx) {
        originalUrl := utils.ImmutableString(c.OriginalURL())

        // Check if the client is requesting a file extension
        extMatch, _ := regexp.MatchString("\\.[a-zA-Z0-9]+$", originalUrl)

        if !strings.HasSuffix(originalUrl, "/") && !extMatch {
            c.Redirect(originalUrl + "/")
        }
        c.Next()
    })

    // Route definitions
    app.Get("/foo/", func(c *fiber.Ctx) {
        c.SendString("I am Foo!")
    })

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

Thanks for asking! 🚀

[suntong]

Why it is closed?

[thomasvvugt]

Hi @suntong,

Like I pointed out in my previous comment, there are no such guidelines to specifically use/not use a trailing / for a URL.
I have also provided a working code example which adds a trailing slash, mimicking the behavior you stated.

Let me know if there are any additional comments regarding the issue or the given code example.

[suntong]

Fine.

Giving the fact that all normal web servers would redirect directories automatically with the extra trailing, I'm still thinking this should be a builtin feature, not even an added middleware, but

It's your code so it is your call.

[Fenny]

It's something we worked on a while back, please see https://github.com/gofiber/fiber/blob/master/app.go#L183. But we never finished the implementation because it impacted the router performance too much.

It's not that we do not want to implement this, but I just couldn't find the time yet to make this feature work without losing to much performance.

PR's are welcome, in the meantime, I have to focus on the v1.14.0 release notes and maybe we can take another look at the RedirectFixedPath feature for v1.14.1 👍

[suntong]

Ah, yeah, that make perfect sense. I.e.,

• adding it as a middleware will have to run the detection for every single request, doing FS IO determining if it is a directory or not, so it will definitely have negative impact on the performance
• however, if it is a builtin feature from the static file server, since the code would have to know if it is a directory or file anyway, and treat it differently, adding a trailing "/" would literately have nearly zero cost. We just have to find the perfect spot to add it.

[suntong]

Giving the fact that all normal web servers would redirect directories automatically with the extra trailing, I'm still thinking this should be a builtin feature, not even an added middleware...

Took a further look at the issue to determine where exactly the problem came from, as fiber is relying on the fasthttp to provide the file server service. So I have added a fasthttp-fileserver check --

https://github.com/suntong/fiber_demo/commit/8ab9321a1fc26f4915ebf097b6339ba1dc965e7e

cd fiber_demo/fasthttp-fileserver
go run fileserver.go -dir ../web 

The check points out that fasthttp-fileserver clearly has such feature builtin -- it would redirect directories automatically with the extra trailing -- http://localhost:8080/sample0 would become http://localhost:8080/sample0/ automatically.

So the problem is somewhere within fiber, not the fasthttp.

[suntong]

So the problem is somewhere within fiber, not the fasthttp.

Seems to have come from
https://github.com/gofiber/fiber/blob/29e8f12a13966ed67161eae2fc0a856f4603bdfa/router.go#L273-L285

What is the logic behind such PathRewrite?
Would it be a better idea just to leave Path Rewrite to fasthttp to handle that?

[suntong]

See https://github.com/gofiber/fiber/pull/819