func waitForConnection(conn *grpc.ClientConn) error {
state := conn.State()
var err error
if state != grpc.Ready {
for {
if !conn.WaitForStateChange(1*time.Second, conn.State()) {
err = errors.New("connection")
}
state := conn.State()
if state == grpc.Connecting || state == grpc.Idle {
continue
} else if state == grpc.TransientFailure {
err = errors.New("fail")
}
break
}
}
return err
}