proxy middleware: reuse echo request context

Author: x1h0

middleware/proxy.go

@@ -359,6 +359,10 @@ func ProxyWithConfig(config ProxyConfig) echo.MiddlewareFunc {
 					c.Set("_error", nil)
 				}
 
+				// Reuse context from echo request
+				// This is needed to access context values in modifyResponse.
+				req = req.WithContext(c.Request().Context())
+
 				// Proxy
 				switch {
 				case c.IsWebSocket():