cloud-init
检查 cloud-init 失败、长时间运行
https://cloudinit.readthedocs.io/en/latest/howto/debugging.html#to-start-debugging
运行以下命令检查 cloud-init 处于哪个阶段：
systemctl status cloud-init-local.service cloud-init.service\
cloud-config.service cloud-final.service关于不同阶段的解释：https://cloudinit.readthedocs.io/en/latest/explanation/boot.html