package wait import ( "fmt" "time" "github.com/xenolf/lego/log" ) // For polls the given function 'f', once every 'interval', up to 'timeout'. func For(msg string, timeout, interval time.Duration, f func() (bool, error)) error { log.Infof("Wait for %s [timeout: %s, interval: %s]", msg, timeout, interval) var lastErr string timeUp := time.After(timeout) for { select { case <-timeUp: return fmt.Errorf("time limit exceeded: last error: %s", lastErr) default: } stop, err := f() if stop { return nil } if err != nil { lastErr = err.Error() } time.Sleep(interval) } }