Add caching headers on 404 responses (#775)

* Add caching headers on 404 responses
drand · Nov 24, 2020 · d6a09ba · d6a09ba
1 parent 22a4797
commit d6a09ba
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/http/server.go b/http/server.go
@@ -254,7 +254,9 @@ func (h *handler) PublicRand(w http.ResponseWriter, r *http.Request) {
 	roundExpectedTime = time.Unix(chain.TimeOfRound(info.Period, info.GenesisTime, roundN), 0)
 
 	if roundExpectedTime.After(time.Now().Add(info.Period)) {
+		timeToExpected := int(time.Until(roundExpectedTime).Seconds())
 		w.WriteHeader(http.StatusNotFound)
+		w.Header().Set("Cache-Control", fmt.Sprintf("public, must-revalidate, max-age=%d", timeToExpected))
 		h.log.Warn("http_server", "request in the future", "client", r.RemoteAddr, "req", url.PathEscape(r.URL.Path))
 		return
 	}
@@ -267,6 +269,7 @@ func (h *handler) PublicRand(w http.ResponseWriter, r *http.Request) {
 	}
 	if data == nil {
 		w.WriteHeader(http.StatusNotFound)
+		w.Header().Set("Cache-Control", "must-revalidate, no-cache, max-age=0")
 		h.log.Warn("http_server", "request in the future", "client", r.RemoteAddr, "req", url.PathEscape(r.URL.Path))
 		return
 	}