bskyweb: do not serve cache headers on non-2XX for static assets

bskyweb/cmd/bskyweb/server.go

@@ -214,6 +214,11 @@ func serve(cctx *cli.Context) error {
 	e.GET("/iframe/youtube.html", echo.WrapHandler(staticHandler))
 	e.GET("/static/*", echo.WrapHandler(http.StripPrefix("/static/", staticHandler)), func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {
+			c.Response().Before(func() {
+				if c.Response().Status >= 300 {
+					return
+				}
+
 				path := c.Request().URL.Path
 				maxAge := 1 * (60 * 60) // default is 1 hour
 
@@ -223,6 +228,7 @@ func serve(cctx *cli.Context) error {
 				}
 
 				c.Response().Header().Set("Cache-Control", fmt.Sprintf("public, max-age=%d", maxAge))
+			})
 			return next(c)
 		}
 	})