how to implement etag in web server?

[thstart]

I want to use etags to reduce bandwidth - are there build in

etags in standard web server?

[minux]

On Sat, Dec 15, 2012 at 1:37 AM, thstart <brag...@bragbuddy.com> wrote:

I want to use etags to reduce bandwidth - are there build in

etags in standard 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)

[thstart]

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?

[Caleb Doxsey]

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