k8s/StudyNotes/Storage

Docker storage - Storage drivers[aufs,btrfs,etc.] and volume's [Local,VMware,rexray/ebs]

/var/lib/docker/ [aufs, containers, image, volumes]

Create persistent storage for docker container

     docker volume create data_vol
     docker run -v data_vol:/var/lib/mysql mysql
     # if no pre-created volume docker creates it on the fly
     
     docker run --mount type=bind,source=/data/mysql,target=/varlib/mysql mysql

Bind mount form anywhere, volume mount from /var/lib/docker/volumes/

k8s - Was just docker, now CRI container runtime interface to support docker,rkt, cri-o
- Same for network CNI Container network interface
- Same for storage CSI Container Storage Interface - Amazon EBS, PureStorage
  - CSI spec https://github.com/container-storage-interface
k8s volume options [hostPath:, nfs, awsElasticBlockStore:, etc]
k8s centralize storage with PersistentVolume, then pods claim matching pv with VolumeClaims.
PV(PersistenVolume) on cloud provider still has to manually created.
- Automate this with Dynamic Provisioning using StorageClass object
- e.g. SC auto creates PV(PersistVol) and PVC(PVclaim) grabs disk from SC
```
apiVersion: storage.k8s.io/v1
kind: storageClass
metadata:
  name: google-storage
provisioner: kubernetes.io/gce-pd
parameters:
  type: pd-standard
  replication-type: none
```
  - In the PVC obj we now refer to the storageClassName: google-storage defined in SC