In this post I will show you how to use a local folder as a persistent volume in Kubernetes.

Parst of the Kubernetes series

• Part1a: Install K8S with ansible
• Part1b: Install K8S with kubeadm
• Part1c: Install K8S with containerd and kubeadm
• Part1d: Install K8S with kubeadm in HA mode
• Part2: Intall metal-lb with K8S
• Part2: Intall metal-lb with BGP
• Part3: Install Nginx ingress to K8S
• Part4: Install cert-manager to K8S
• Part5a: Use local persisten volume with K8S
• Part5b: Use ceph persisten volume with K8S
• Part5c: Use ceph CSI persisten volume with K8S
• Part5d: Use Project Longhorn as persisten volume with K8S
• Part5e: Use OpenEBS as persisten volume with K8S
• Part5f: vSphere persistent storage for K8S
• Part6a: Install k8s with IPVS mode
• Part6b: Install k8s with IPVS mode
• Part7: Use Helm with K8S
• Part8: Tillerless helm2 install
• Part9: Kubernetes Dashboard SSO
• Part10: Kuberos for K8S
• Part11: Gangway for K8S
• Part12: Velero Backup for K8S

For a production environment this is not an ideal structure because if you store the data on a single host if the host dies your data will be lost. For this Demo I will use a separate disk for storing the PV’s folders. So you can backup or replicate this disk separately.

Configure the disk

vgcreate local-vg /dev/sdd
lvcreate -l 100%FREE -n local-lv local-vg /dev/sdd
mkfs.xfs -f /dev/local-vg/local-lv
mkdir -p /mnt/local-storage/
mount /dev/local-vg/local-lv /mnt/local-storage
echo "/dev/local-vg/local-lv        /mnt/local-storage              xfs defaults 0 0" >> /etc/fstab
rm -rf /mnt/local-storage/lost+found

Now you can create every PV and PVC manually.

mkdir /mnt/local-storage/pv-tst

cat pv-tst.yaml
---
kind: PersistentVolume
apiVersion: v1
metadata:
  name: pv-tst
spec:
  capacity:
    storage: 1Gi
  local:
    path: /mnt/local-storage/pv-tst
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local
  nodeAffinity:
    required:
      nodeSelectorTerms:
        - matchExpressions:
            - key: kubernetes.io/hostname
              operator: In
              values:
                - kubernetes03.devopstales.intra
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: pv-tst
  namespace: tst
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  volumeName: pv-tst
  storageClassName: local

Add automated hostpath-provisioner

This is a Persistent Volume Claim (PVC) provisioner for Kubernetes. It dynamically provisions hostPath volumes to provide storage for PVCs.

git clone https://github.com/torchbox/k8s-hostpath-provisioner
cd k8s-hostpath-provisioner
kubectl apply -f deployment.yaml

nano local-sc.yaml
---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: auto-local
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: torchbox.com/hostpath
parameters:
  pvDir: /mnt/local-storage

Test the provisioner by creating a new PVC:

cat testpvc.yaml
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: testpvc
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 50Gi

kubectl create -f testpvc.yaml
kubectl get pvc
NAME      STATUS    VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
testpvc   Bound     pvc-145c785e-ab83-11e7-9432-4201ac1fd019   50Gi       RWX            auto-local     10s