StorageClass: local path provider

今天簡單演示如何在Kubernetes cluster利用local-path provider建構出storage class來提供應用程式進行資料的存放。

每個節點的/opt/local-path-provisioner路徑用來存放資料，預設安裝在local-path-storage namespace。

建議測試使用，實務上建議採用CSI連接到外部儲存。

1. Procedures

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* S1-1. Deploy
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# wget https://raw.githubusercontent.com/rancher/local-path-provisioner/v0.0.24/deploy/local-path-storage.yaml
# kubectl create -f local-path-storage.yaml

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* S1-2. verify
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# kubectl get all -n local-path-storage

2. 部署應用服務

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* S2-1. create app
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# wget https://raw.githubusercontent.com/rancher/local-path-provisioner/master/examples/pvc/pvc.yaml
# wget https://raw.githubusercontent.com/rancher/local-path-provisioner/master/examples/pod/pod.yaml
# kubectl create -f pvc.yaml
# kubectl create -f pod.yaml

# kubectl get pvc
# kubectl get pod

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* S2-2. Write data
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# kubectl exec volume-test -- sh -c "echo local-path-test > /data/test"
# kubectl delete -f pod.yaml
# kubectl create -f pod.yaml (recreate)
# kubectl exec volume-test -- sh -c "cat /data/test"
local-path-test  (依然存在)

以上就是最簡單的做法，接下來將分析local volume與hostpath二種做法的差異。