func proxyAsync(engine *cluster.Engine, w http.ResponseWriter, r *http.Request, callback func(*http.Response)) error {
// RequestURI may not be sent to client
r.RequestURI = ""
client, scheme := engine.HTTPClientAndScheme()
r.URL.Scheme = scheme
r.URL.Host = engine.Addr
log.WithFields(log.Fields{"method": r.Method, "url": r.URL}).Debug("Proxy request")
resp, err := client.Do(r)
if err != nil {
return err
}
copyHeader(w.Header(), resp.Header)
w.WriteHeader(resp.StatusCode)
io.Copy(NewWriteFlusher(w), resp.Body)
if callback != nil {
callback(resp)
}
// cleanup
resp.Body.Close()
return nil
}
