Golang & Gorilla Sessions - Cache Prevents Logout Functionality

问题

I've built an application that uses the Go Gorilla sessions package. Everything seems fine, except when on logout I implement

func logout(w http.ResponseWriter, r *http.Request) {
  session, _ := store.Get(r, "authsesh")
  session.Values["access"] = "denied"
  session.Save(r, w)
  http.Redirect(w, r, "/", 302)
  return
}

Because the page requiring authentication is cached by the browser, it can still be accessed after logout. How can I get around that? Is there a way to prevent the browser from caching the page? There's nothing wrong with the cookie, if I clear the cache and keep the cookie I can see the logout has had the desired effect.

回答1:

Set the correct cache headers in your handler(s):

w.Header().Set("Cache-Control", "no-cache, private, max-age=0")
w.Header().Set("Expires", time.Unix(0, 0).Format(http.TimeFormat))
w.Header().Set("Pragma", "no-cache")
w.Header().Set("X-Accel-Expires", "0")

Note that we set multiple headers to account for proxies and HTTP/1.0 clients.

You can wrap these into middleware you can apply as well:

func NoCache(h http.Handler) http.Handler) {
    fn := func(w http.ResponseWriter, r *http.Request) {
        // Set the headers
    }

    return http.HandlerFunc(fn)
}

// In your router
http.Handle("/user-dashboard", NoCache(http.HandlerFunc(YourDashboardHandler))

来源：https://stackoverflow.com/questions/35086688/golang-gorilla-sessions-cache-prevents-logout-functionality