You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
58 lines
1.4 KiB
58 lines
1.4 KiB
package middleware
|
|
|
|
// Ported from Goji's middleware, source:
|
|
// https://github.com/zenazn/goji/tree/master/web/middleware
|
|
|
|
import (
|
|
"net/http"
|
|
"time"
|
|
)
|
|
|
|
// Unix epoch time
|
|
var epoch = time.Unix(0, 0).Format(time.RFC1123)
|
|
|
|
// Taken from https://github.com/mytrile/nocache
|
|
var noCacheHeaders = map[string]string{
|
|
"Expires": epoch,
|
|
"Cache-Control": "no-cache, no-store, no-transform, must-revalidate, private, max-age=0",
|
|
"Pragma": "no-cache",
|
|
"X-Accel-Expires": "0",
|
|
}
|
|
|
|
var etagHeaders = []string{
|
|
"ETag",
|
|
"If-Modified-Since",
|
|
"If-Match",
|
|
"If-None-Match",
|
|
"If-Range",
|
|
"If-Unmodified-Since",
|
|
}
|
|
|
|
// NoCache is a simple piece of middleware that sets a number of HTTP headers to prevent
|
|
// a router (or subrouter) from being cached by an upstream proxy and/or client.
|
|
//
|
|
// As per http://wiki.nginx.org/HttpProxyModule - NoCache sets:
|
|
// Expires: Thu, 01 Jan 1970 00:00:00 UTC
|
|
// Cache-Control: no-cache, private, max-age=0
|
|
// X-Accel-Expires: 0
|
|
// Pragma: no-cache (for HTTP/1.0 proxies/clients)
|
|
func NoCache(h http.Handler) http.Handler {
|
|
fn := func(w http.ResponseWriter, r *http.Request) {
|
|
|
|
// Delete any ETag headers that may have been set
|
|
for _, v := range etagHeaders {
|
|
if r.Header.Get(v) != "" {
|
|
r.Header.Del(v)
|
|
}
|
|
}
|
|
|
|
// Set our NoCache headers
|
|
for k, v := range noCacheHeaders {
|
|
w.Header().Set(k, v)
|
|
}
|
|
|
|
h.ServeHTTP(w, r)
|
|
}
|
|
|
|
return http.HandlerFunc(fn)
|
|
}
|
|
|