Function makeImageCORSMiddleware

httpserver/image_cors.go:5–22

(allowedOrigins []string)

import "net/http"

func makeImageCORSMiddleware(allowedOrigins []string) func(http.Handler) http.Handler {
	allowed := make(map[string]struct{}, len(allowedOrigins))
	for _, o := range allowedOrigins {
		allowed[o] = struct{}{}
	}
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			origin := r.Header.Get("Origin")
			if origin != "" {
				if _, ok := allowed[origin]; ok {
					w.Header().Set("Access-Control-Allow-Origin", origin)
					w.Header().Add("Vary", "Origin")
				}
			}
			next.ServeHTTP(w, r)
		})
	}
}