retry golang

retry.go

type Retry struct {
	http.RoundTripper
}

func (r *Retry) RoundTrip(req *http.Request) (*http.Response, error) {
	for {
		log.Printf("retry: doing request %s\n", req.URL)
		resp, err := r.RoundTripper.RoundTrip(req)

		if err == nil && resp.StatusCode < 500 {
			return resp, err
		}

		// discard
		if resp != nil {
			resp.Body.Close()
		}

		select {
		case <-req.Context().Done():
			return resp, req.Context().Err()
		case <-time.After(2 * time.Second):
		}
	}
}