add no-cache to Cache-Control on static files

backend/app/rest/api/rest.go

@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
-	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -587,7 +586,7 @@ func cacheControl(expiration time.Duration, version string) func(http.Handler) h
 		fn := func(w http.ResponseWriter, r *http.Request) {
 			e := `"` + etag(r, version) + `"`
 			w.Header().Set("Etag", e)
-			w.Header().Set("Cache-Control", "max-age="+strconv.Itoa(int(expiration.Seconds())))
+			w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%d, no-cache", int(expiration.Seconds())))
 
 			if match := r.Header.Get("If-None-Match"); match != "" {
 				if strings.Contains(match, e) {

backend/app/rest/api/rest_test.go

@@ -326,7 +326,7 @@ func TestRest_cacheControl(t *testing.T) {
 			assert.Equal(t, http.StatusOK, resp.StatusCode)
 			t.Logf("%+v", resp.Header)
 			assert.Equal(t, `"`+tt.etag+`"`, resp.Header.Get("Etag"))
-			assert.Equal(t, `max-age=`+strconv.Itoa(int(tt.exp.Seconds())), resp.Header.Get("Cache-Control"))
+			assert.Equal(t, `max-age=`+strconv.Itoa(int(tt.exp.Seconds()))+", no-cache", resp.Header.Get("Cache-Control"))
 
 		})
 	}