adding cache-control age and disabler

2 files changed, 26 insertions, 11 deletions

diff --git a/system/db/cache.go b/system/db/cache.go
index 0120147..55dd42a 100644
--- a/system/db/cache.go
+++ b/system/db/cache.go
@@ -11,19 +11,29 @@ import (
 // CacheControl sets the default cache policy on static asset responses
 func CacheControl(next http.Handler) http.HandlerFunc {
 	return http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
-		etag := ConfigCache("etag").(string)
-		policy := fmt.Sprintf("max-age=%d, public", 60*60*24*30)
-		res.Header().Add("ETag", etag)
-		res.Header().Add("Cache-Control", policy)
-
-		if match := req.Header.Get("If-None-Match"); match != "" {
-			if strings.Contains(match, etag) {
-				res.WriteHeader(http.StatusNotModified)
-				return
+		cacheDisabled := ConfigCache("cache_disabled").(bool)
+		if cacheDisabled {
+			res.Header().Add("Cache-Control", "no-cache")
+			next.ServeHTTP(res, req)
+		} else {
+			age := ConfigCache("cache_max_age").(int64)
+			etag := ConfigCache("etag").(string)
+			if age == 0 {
+				age = DefaultMaxAge
+			}
+			policy := fmt.Sprintf("max-age=%d, public", age)
+			res.Header().Add("ETag", etag)
+			res.Header().Add("Cache-Control", policy)
+
+			if match := req.Header.Get("If-None-Match"); match != "" {
+				if strings.Contains(match, etag) {
+					res.WriteHeader(http.StatusNotModified)
+					return
+				}
 			}
-		}
 
-		next.ServeHTTP(res, req)
+			next.ServeHTTP(res, req)
+		}
 	})
 }
 
diff --git a/system/db/config.go b/system/db/config.go
index 2706e97..6a409c2 100644
--- a/system/db/config.go
+++ b/system/db/config.go
@@ -13,6 +13,11 @@ import (
 	"github.com/gorilla/schema"
 )
 
+const (
+	// DefaultMaxAge provides a 2592000 second (30-day) cache max-age setting
+	DefaultMaxAge = int64(60 * 60 * 24 * 30)
+)
+
 var configCache map[string]interface{}
 
 func init() {