# K8s Lifecycle

###### tags: `K8s`

# minikube
archlinux安裝minikube driver kvm2
> pacman -S minikube libvirt qemu-desktop dnsmasq iptables-nft kubelet
> sudo systemctl start kubelet
> usermod -aG libvirt $(whoami)
> minikube config set driver kvm2 //設定driver使用kvm2
> reboot //因為kvm2牽涉kernel，需要重開
> sudo systemctl start libvird
> minikube start

[使用qemu來安裝minikube](https://wiki.archlinux.org/title/Minikube)
備註：後來發現使用docker當driver也可以正常運作，效能也較佳

# 基本快速啟動指南

1. 清除舊資料

> minikube delete --all

2. 事先請安裝docker跟kubectl
3. 下載新版minikube

> curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
> sudo install minikube-linux-amd64 /usr/local/bin/minikube

4. minikube start
5. 開啟vs code，編寫deployment.yaml檔案
請預先安裝k8s相關套件，可以自動生成文件架構

6. 輸入deployment，調整app name、image、port等

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: myapp
        image: rossning92/finance
        resources:
          limits:
            memory: "128Mi"
            cpu: "500m"
        ports:
        - containerPort: 5000
---
apiVersion: v1
kind: Service
metadata:
  name: myapp
spec:
  selector:
    app: myapp
  type: NodePort
  ports:
  - port: 5000
    targetPort: 5000

7. 佈署
> kubectl apply -f deployment.yaml
8. 檢視pod運作
> kubectl get pods

9. 檢視服務
> kubectl get services
檢視特定服務，輸入後就可以直接跑到那個服務的網站
> minikube service SERVICE_NAME

10. 異動配置
直接修改deployment.yaml內容後，再一次佈署，就會慢慢佈署完成
> kubectl apply -f deployment.yaml
11. 移除服務
> kubectl delete -f deployment.yaml

[第一篇](https://cwhu.medium.com/kubernetes-basic-concept-tutorial-e033e3504ec0)
[第二篇](https://cwhu.medium.com/kubernetes-implement-ingress-deployment-tutorial-7431c5f96c3e)
[第三篇](https://cwhu.medium.com/kubernetes-helm-chart-tutorial-fbdad62a8b61)

1. 建立image
> docker build -t yourDockerAccount/yourDockerApp

2. push 到某一個image repos
> docker push yourDockerAccount/yourDockerApp:latest

3. 第一個pod yaml
> apiVersion: v1
> kind: Pod
> metadata:
> name: kubernetes-demo-pod
> labels:
> app: demoApp
> spec:
> containers:
> - name: kubernetes-demo-container
> image: hcwxd/kubernetes-demo
> ports:
> - containerPort: 3000

4. 建立pod => 因應多pod建置，可改用10.Deployment
> kubectl create -f kubernetes-demo.yaml

5. 查詢pod狀況

> kubectl get pods

6. 連線到pod =>因應多pod連線問題，可改用7.service.yaml處理取代
> kubectl port-forward kubernetes-demo-pod 3000:3000

7. 建立service yaml
> apiVersion: v1
> kind: Service
> metadata:
> name: my-service
> spec:
> selector:
> app: demoApp
> type: NodePort
> ports:
> - protocol: TCP
> port: 3001
> targetPort: 3000
> nodePort: 30390

8. 建立Service元件
> kubectl create -f service.yaml

9. 取得服務狀態
> kubectl get services

10. 建立 Deployment元件

> apiVersion: apps/v1
> kind: Deployment
> metadata:
> name: my-deployment
> spec:
> replicas: 3
> template:
> metadata:
> labels:
> app: demoApp
> spec:
> containers:
> - name: kubernetes-demo-container
> image: hcwxd/kubernetes-demo
> ports:
> - containerPort: 3000
> selector:
> matchLabels:
> app: demoApp

11. 部署
> kubectl create -f deployment.yaml

12. 取得狀態
> kubectl get deploy

13. 版本deployment 歷史
> kubectl rollout history deployment my-deployment

14. 還原上一版
> kubectl rollout undo deploy my-deployment

15. 還原指定版本
> kubectl rollout undo deploy my-deployment --to-revision=2