Volume

Dynamic Provisioning, StorageClass, Status, ReclaimPolicy
Version 1.27 에서는 스토리지 솔루션을 Longhorn으로 대체합니다.
강의자료 PDF
Volume with PV, PVC Concept for Kubernetes.


1. Longhorn 구축

1-1) 모든 Master/Work Node에 iscsi 설치

yum --setopt=tsflags=noscripts install -y iscsi-initiator-utils
echo "InitiatorName=$(/sbin/iscsi-iname)" > /etc/iscsi/initiatorname.iscsi
systemctl enable iscsid
systemctl start iscsid

1-2) Longhorn 설치

kubectl apply -f https://raw.githubusercontent.com/kubetm/kubetm.github.io/master/yamls/longhorn/longhorn-1.5.0.yaml
kubectl apply -f https://raw.githubusercontent.com/kubetm/kubetm.github.io/master/yamls/longhorn/longhorn-1.3.3.yaml

확인

kubectl get pods -n longhorn-system

Longhorn Replica가 너무 많이 생성되니 줄여봅니다.

kubectl scale deploy -n longhorn-system csi-attacher --replicas=1
kubectl scale deploy -n longhorn-system csi-provisioner --replicas=1
kubectl scale deploy -n longhorn-system csi-resizer --replicas=1
kubectl scale deploy -n longhorn-system csi-snapshotter --replicas=1
kubectl scale deploy -n longhorn-system longhorn-ui --replicas=1

1-3) Fast StorageClass 추가

kubectl apply -f - <<END
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: fast
provisioner: driver.longhorn.io
parameters:
  dataLocality: disabled
  fromBackup: ""
  fsType: ext4
  numberOfReplicas: "3"
  staleReplicaTimeout: "30"
END

1-4) StorageClass 생성 확인

kubectl get storageclasses.storage.k8s.io

NAME                 PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
fast                 driver.longhorn.io      Delete          Immediate              false                  16s
longhorn (default)   driver.longhorn.io      Delete          Immediate              true                   85m

1-5) Dashboard 접속을 위한 Service 수정

Service Type 변경 [ClusterIP -> NodePort]

kubectl edit svc -n longhorn-system longhorn-frontend

  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: http
    nodePort: 30705  # port 번호 추가
  type: NodePort      # type 변경

1-6) Longhorn Dashboard 접속

http://192.168.56.30:30705



2. Dynamic Provisioning

Volume with Dynamic Provisioning Practice for Kubernetes - Longhorn.

2-1) PersistentVolume

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-hostpath1
spec:
  capacity:
    storage: 1G
  accessModes:
  - ReadWriteOnce
  hostPath:
    path: /mnt/hostpath
    type: DirectoryOrCreate

2-2) PersistentVolumeClaim

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-hostpath1
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1G
  storageClassName: ""

2-3) PersistentVolumeClaim

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-fast1
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1G
  storageClassName: "fast"

2-4) PersistentVolumeClaim

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-default1
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 2G


3. PV Status, ReclaimPolicy

Volume with PV Status, ReclaimPolicy Practice for Kubernetes.

3-1) Pod

apiVersion: v1
kind: Pod
metadata:
  name: pod-hostpath1
spec:
  nodeSelector:
    kubernetes.io/hostname: k8s-node1
  terminationGracePeriodSeconds: 0
  containers:
  - name: container
    image: kubetm/init
    volumeMounts:
    - name: hostpath
      mountPath: /mount1
  volumes:
  - name: hostpath
    persistentVolumeClaim:
      claimName: pvc-hostpath1

cd /mount1
touch file.txt

Longhorn Dashboard

http://192.168.56.30:30705

Volume with ReclaimPolicy Recycle Practice for Kubernetes.

3-2) PersistentVolume

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-recycle1
spec:
  persistentVolumeReclaimPolicy: Recycle
  capacity:
    storage: 3G
  accessModes:
  - ReadWriteOnce
  hostPath:
    path: /tmp/recycle
    type: DirectoryOrCreate

3-3) PersistentVolumeClaim

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-recycle1
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 3G
  storageClassName: ""

3-4) Pod

apiVersion: v1
kind: Pod
metadata:
  name: pod-recycle1
spec:
  nodeSelector:
    kubernetes.io/hostname: k8s-node1
  terminationGracePeriodSeconds: 0
  containers:
  - name: container
    image: kubetm/init
    volumeMounts:
    - name: hostpath
      mountPath: /mount1
  volumes:
  - name: hostpath
    persistentVolumeClaim:
      claimName: pvc-recycle1

cd /mount1
touch file.txt




kubectl

Force Deletion

kubectl delete persistentvolumeclaims pvc-fast1 --namespace=default --grace-period 0 --force
kubectl delete persistentvolume pvc-b53fd802-3919-4fb0-8c1f-02221a3e4bc0 --grace-period 0 --force


Tips

hostPath

  • Recycle 정책은 /tmp/로 시작하는 Path에서만 됨


Referenece

Kubernetes

Others