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HostPath Volume
Simply add hostpath to volumes section in the deployment definition:
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volumes:
- name: local-vol
hostPath:
path: {{ .Values.persistentVolume.path }}
type: DirectoryDirectoryOrCreate
Example:
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kind: Deployment apiVersion: apps/v1 metadata: ... spec: containers: - name: registry ... labels volumeMounts: - appmountPath: /var/lib/registry spec: name: local-vol replicas subPath: 1registry/data selector: matchLabelsvolumes: app- name: registrylocal-vol revisionHistoryLimit: 10 templatehostPath: metadata: labels: path: {{ .Values.persistentVolume.path }} apptype: registry spec: containers: - name: registry ... volumeMounts: - mountPath: /var/lib/registry name: local-vol subPath: registry/data volumes:DirectoryOrCreate ... |
HostPath Storage using Persistent Volume
This is the simplest and best approach for bare metal deployments when a network file system is not available.
Define storage class and make it the default
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apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: hostpath-storage
annotations:
storageclass.kubernetes.io/is-default-class: "true"
provisioner: keystone/hostpath-storage
volumeBindingMode: Immediate
reclaimPolicy: Retain |
Remove default status from other storage classes
> kubectl patch storageclass <STORAGE_CLASS> -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'
Create Persistent Volumes
This example creates 10 persistent volumes using helm
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{{- $root := . -}} {{range $i, $e := until 10}} apiVersion: v1 kind: PersistentVolume metadata: name: pv-{{ $i }} spec: capacity: storage: {{ $root.Values.persistentVolume.size }} volumeMode: Filesystem accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Retain storageClassName: hostpath-storage hostPath: path: /var/pv/pv-{{ $i }} type: DirectoryOrCreate nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname - nameoperator: local-volNotIn hostPath values: path: {{ .Values.persistentVolume.path }} - master --- {{end}} |
Make a Claim using Default Storage Class
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kind: PersistentVolumeClaim apiVersion: v1 metadata: name: my-claim spec: storageClassName: "" accessModes: - ReadWriteOnce resources: requests: storage: 2Gi type: Directory ... |
Local Storage using Persistent Volume and ClaimClaim
We can use disk space on a node by defining a PersistentVolume (see below) and then making a claim against that volume by specifying the storageclass name in the PersistentVolumeClaim.
- Only one claim can be made against a volume.
- File path (local.path) must exist for the volume to be usable.
- USE HOSTPATH STORAGE since it will create the folders for you.
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apiVersion: v1 kind: PersistentVolume metadata: name: local-storage spec: capacity: storage: 10Gi # volumeMode field requires BlockVolume Alpha feature gate to be enabled. volumeMode: Filesystem accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Persist storageClassName: local-storage local: path: /var/k8s/LOCAL_STORAGE nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - k8sworker1 - k8sworker2 - k8sworker3 - docker-for-desktop |
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Make a claim by specifying the storage class
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kind: PersistentVolumeClaim apiVersion: v1 metadata: name: local-storage-claim spec: storageClassName: local-storage accessModes: - ReadWriteOnce resources: requests: storage: 3Gi |
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We can create a storage class for our local-storage and use it as default storage. The only issue with doing this with local-storage is that we need to pre-build all of the persistent volumes. Since only 1 claim can be made against a volume, we will need to make a few.
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apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: local-storage annotations: storageclass.kubernetes.io/is-default-class: "true" provisioner: keystone/local-storage volumeBindingMode: Immediate reclaimPolicy: Retain --- apiVersion: v1 kind: PersistentVolume metadata: name: local-storage-1 spec: capacity: storage: 2Gi volumeMode: Filesystem accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Retain storageClassName: local-storage local: path: /var/pv1 nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: NotIn values: - master --- ...REPEAT UNTIL HAPPY ... |
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To use the default storage of the cluster, you just need to create a claim and specify "" for storageClassName.
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kind: PersistentVolumeClaim apiVersion: v1 metadata: name: local-storage-claim spec: storageClassName: "" accessModes: - ReadWriteOnce resources: requests: storage: 3Gi |
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