容器存储接口 CSI 相关知识

参考：

https://blog.csdn.net/lovely_nn/article/details/122880876
https://developer.aliyun.com/article/783464
https://www.cnblogs.com/varden/p/15139819.html

存储商需实现 CSI 插件的 NodeGetVolumeStats 接口，Kubelet 会调用该函数，并反映在其 metrics上：

 kubelet_volume_stats_capacity_bytes：存储卷容量
 kubelet_volume_stats_used_bytes：存储卷已使用容量
 kubelet_volume_stats_available_bytes：存储卷可使用容量
 kubelet_volume_stats_inodes：存储卷 inode 总量
 kubelet_volume_stats_inodes_used：存储卷 inode 使用量
 kubelet_volume_stats_inodes_free：存储卷 inode 剩余量

k8s 1.19.4 kubelet stops presenting kubelet_volume_stats_used_bytes metrics

https://github.com/kubernetes/kubernetes/issues/97138

CSI driver

https://kubernetes.io/docs/concepts/storage/volume-health-monitoring/
https://kubernetes-csi.github.io/docs/drivers.html

kube-state-metrics官网

https://github.com/kubernetes/kube-state-metrics