Allow specific cors origin value

http-dev.go

@@ -9,14 +9,13 @@ import (
 	"time"
 )
 
-var listenFlag, targetFlag, hostFlag string
-var allowCors bool
+var listenFlag, targetFlag, hostFlag, allowCors string
 
 func main() {
 	flag.StringVar(&listenFlag, "listen", ":8080", "Listen address")
 	flag.StringVar(&targetFlag, "target", "", "Set target URL to forward to")
 	flag.StringVar(&hostFlag, "host", "", "Set the host value")
-	flag.BoolVar(&allowCors, "cors", false, "Allow all cross origin requests")
+	flag.StringVar(&allowCors, "cors", "", "Set cross origin domain or '*' for all origins")
 	flag.Parse()
 
 	target, err := url.Parse(targetFlag)
@@ -33,14 +32,11 @@ func main() {
 			r.Out.Header = r.In.Header.Clone()
 		},
 		ModifyResponse: func(resp *http.Response) error {
-			if !allowCors {
-				return nil
-			}
-
-			resp.Header.Set("Access-Control-Allow-Origin", "*")
+			if allowCors != "" {
+				resp.Header.Set("Access-Control-Allow-Origin", allowCors)
 				resp.Header.Set("Access-Control-Allow-Credentials", "true")
 				resp.Header.Set("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")
-			resp.Header.Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
+				resp.Header.Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, HEAD, DELETE")
 
 				if resp.Request.Method == http.MethodOptions {
 					resp.Header.Set("Content-Type", "text/plain; charset=utf-8")
@@ -48,6 +44,7 @@ func main() {
 					resp.StatusCode = http.StatusNoContent
 					resp.Status = http.StatusText(http.StatusNoContent)
 				}
+			}
 			return nil
 		},
 	}
@@ -66,7 +63,7 @@ func main() {
 	if hostFlag != "" {
 		log.Printf("- Rewriting host to '%s'\n", hostFlag)
 	}
-	if allowCors {
+	if allowCors != "" {
 		log.Println("- Allowing all cross-origin requests")
 	}
 	if err := s.ListenAndServe(); err != nil {