[go-nuts] how to implement etag in web server?

if your handle use http.ServeContent to serve content and set ETag in header
before calling that, net/http will automatically handle some ETag related
stuff
for you (If-Non-Match, for example)

--

I am using following code:

var webroot = flag.String("root", "/public", "web root directory")

func handler(w http.ResponseWriter, r *http.Request) {
...
}
http.Handle("/images/", http.StripPrefix("",
http.FileServer(http.Dir(*webroot))))
http.HandleFunc("/", handler)
http.ListenAndServe(listenAddr, nil)

What I need to set so the etag be computed for the static files in webroot?

You're going to have to write a custom handler instead of just using the
built in FileServer. Something like:

- Create a function to use with http.Handle("/images/", ...)
- Make that function take the path the user sends in and translate it
into the filename
- Open the file and compute the hash of the file (might want to cache
this...)
- Add the ETag header
- As minux said use ServeContent to send it back to the user

ETags are sub-optimal. A better approach is to set the content to never
expire and use a hash in the URL.

http://blog.sendhub.com/post/36219926831/how-to-serve-django-statics-and-not-go-insane