Simple Blog

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# 现在的做法（痛苦版）
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1. 创建新版本Pod：kubectl apply -f app-v2-pod.yaml
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2. 等待新Pod就绪
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3. 手动删除旧Pod：kubectl delete pod app-v1-pod
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4. 如果出问题？再手动创建v1版本？
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5. 有10个Pod？重复10遍！😱

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# 某个Pod突然崩溃了
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kubectl get pods
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# app-pod-1   1/1   Running   0   5m
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# app-pod-2   0/1   Error     0   2m    ← 挂了！
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# app-pod-3   1/1   Running   0   5m
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# 你需要：
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1. 发现它挂了（盯着监控？）
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2. 手动重建：kubectl apply -f app-pod-2.yaml
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3. 24小时值班？😭

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# 老板：流量暴增，赶紧从3个Pod扩到10个！
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# 你：好的！（开始复制粘贴YAML...）
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cat > app-pod-4.yaml <<EOF
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apiVersion: v1
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kind: Pod
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metadata:
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  name: app-pod-4  # 手动改名
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  labels:
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    app: myapp
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spec:
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  containers:
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  - name: app
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    image: myapp:v1
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EOF
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# 重复7次...手指抽筋 😵

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# 修改deployment.yaml中的镜像版本
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vi nginx-deployment.yaml
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# 将 image: nginx:1.20 改为 image: nginx:1.21
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# 应用更改
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kubectl apply -f nginx-deployment.yaml

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# 语法：kubectl set image deployment/<名称> <容器名>=<新镜像>
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kubectl set image deployment/nginx-deployment nginx=nginx:1.21
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# 如果有多个容器
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kubectl set image deployment/nginx-deployment \
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  nginx=nginx:1.21 \
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  sidecar=busybox:1.30.1

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kubectl edit deployment nginx-deployment
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# 在编辑器中修改image字段
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# 保存退出后自动应用

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# 查看Deployment状态
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kubectl get deployment nginx-deployment
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# 实时监控（watch模式）
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kubectl get deployment nginx-deployment -w
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# 查看详细更新过程
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kubectl rollout status deployment/nginx-deployment

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$ kubectl rollout status deployment/nginx-deployment
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Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 3 new replicas have been updated...
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Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 3 new replicas have been updated...
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Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
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Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
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Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
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Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
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Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
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deployment "nginx-deployment" successfully rolled out

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kubectl get replicaset
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# NAME                          DESIRED   CURRENT   READY   AGE
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# nginx-deployment-7d64c8b9f5   3         3         3       5m   ← 旧版本（保留）
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# nginx-deployment-86b7dbdd8b   3         3         3       1m   ← 新版本（活跃）

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kubectl get pods -l app=nginx --watch
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# 可以看到旧Pod逐个删除，新Pod逐个创建

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# 查看历史版本
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kubectl rollout history deployment/nginx-deployment
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# 输出示例：
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# REVISION  CHANGE-CAUSE
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# 1         <none>
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# 2         <none>
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# 3         kubectl set image deployment/nginx-deployment nginx=nginx:1.21

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# 方法1：在apply时添加--record参数（已废弃，但仍可用）
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kubectl apply -f nginx-deployment.yaml --record
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# 方法2：使用kubernetes.io/change-cause注解（推荐）
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kubectl annotate deployment/nginx-deployment \
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  kubernetes.io/change-cause="升级到nginx 1.21版本"

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# 查看版本2的详细配置
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kubectl rollout history deployment/nginx-deployment --revision=2

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kubectl rollout undo deployment/nginx-deployment

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# 先查看历史
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kubectl rollout history deployment/nginx-deployment
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# 回滚到版本2
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kubectl rollout undo deployment/nginx-deployment --to-revision=2

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# 暂停更新
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kubectl rollout pause deployment/nginx-deployment
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# 此时更新会停止，部分Pod是新版本，部分是旧版本
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# 可以验证新版本是否正常
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# 确认无问题后，恢复更新
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kubectl rollout resume deployment/nginx-deployment
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# 如果有问题，直接回滚
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kubectl rollout undo deployment/nginx-deployment

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# 1. 准备更新
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kubectl set image deployment/nginx-deployment nginx=nginx:1.21
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# 2. 立即暂停（只更新少量Pod）
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kubectl rollout pause deployment/nginx-deployment
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# 3. 验证新版本（可能只有1-2个Pod是新版本）
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curl http://new-pod-ip  # 测试新版本
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# 4. 如果正常，恢复更新
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kubectl rollout resume deployment/nginx-deployment
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# 5. 如果异常，回滚
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kubectl rollout undo deployment/nginx-deployment

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# 方法1：使用kubectl scale
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kubectl scale deployment/nginx-deployment --replicas=10
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# 方法2：修改YAML并apply
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# 将replicas: 3 改为 replicas: 10
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kubectl apply -f nginx-deployment.yaml

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# 缩减到1个副本
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kubectl scale deployment/nginx-deployment --replicas=1

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# 实时监控
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kubectl get pods -l app=nginx -w
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# 查看Deployment状态
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kubectl get deployment nginx-deployment
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# NAME                READY   UP-TO-DATE   AVAILABLE   AGE
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# nginx-deployment    10/10   10           10          5m

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# 下载部署文件
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wget https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml
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# 修改配置（重要！）
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vi components.yaml
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# 在Deployment的容器args中添加：
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# - --kubelet-insecure-tls
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# - --kubelet-preferred-address-types=InternalIP
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# 应用部署
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kubectl apply -f components.yaml
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# 验证是否正常
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kubectl get pods -n kube-system | grep metrics-server
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kubectl top nodes   # 查看节点资源使用情况
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kubectl top pods    # 查看Pod资源使用情况

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# 方法1：命令行创建
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kubectl autoscale deployment nginx-deployment \
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  --min=2 \
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  --max=10 \
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  --cpu-percent=50
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# 方法2：使用YAML（更灵活）
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cat > nginx-hpa.yaml <<EOF
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apiVersion: autoscaling/v2
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kind: HorizontalPodAutoscaler
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metadata:
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  name: nginx-hpa
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spec:
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  scaleTargetRef:
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    apiVersion: apps/v1
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    kind: Deployment
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    name: nginx-deployment
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  minReplicas: 2          # 最少2个Pod
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  maxReplicas: 10         # 最多10个Pod
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  metrics:
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  - type: Resource
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    resource:
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      name: cpu
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      target:
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        type: Utilization
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        averageUtilization: 50  # CPU平均使用率50%
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  - type: Resource
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    resource:
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      name: memory
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      target:
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        type: Utilization
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        averageUtilization: 70  # 内存平均使用率70%
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EOF
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kubectl apply -f nginx-hpa.yaml

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# 查看HPA
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kubectl get hpa
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# 输出示例：
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# NAME        REFERENCE                    TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
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# nginx-hpa   Deployment/nginx-deployment  45%/50%   2         10        3          5m
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# TARGETS显示：当前值/目标值
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# 查看HPA详细信息
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kubectl describe hpa nginx-hpa

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# 方法1：使用Apache Bench
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kubectl run -it --rm load-generator --image=busybox -- /bin/sh
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# 在容器内执行：
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while true; do wget -q -O- http://nginx-service; done
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# 方法2：使用专业压测工具
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kubectl run load-generator --image=k8s.gcr.io/hpa-example \
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  --requests=cpu=200m -- /bin/sh -c "while true; do echo 'test'; done"
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# 观察HPA自动扩容
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kubectl get hpa -w
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kubectl get deployment nginx-deployment -w

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# 确认镜像存在
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curl -u admin:12345 http://reg.westos.org/v2/library/nginx-php/tags/list

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cd /root/k8s-yaml
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cat > nginx-deployment.yaml <<EOF
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apiVersion: apps/v1
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kind: Deployment
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metadata:
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  name: nginx-deployment
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  labels:
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    app: nginx
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spec:
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  replicas: 3
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  selector:
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    matchLabels:
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      app: nginx
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  template:
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    metadata:
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      labels:
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        app: nginx
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    spec:
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      containers:
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      - name: nginx
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        image: reg.westos.org/library/nginx-php:v1
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        ports:
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        - containerPort: 80
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        env:
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        - name: APP_VERSION
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          value: "v1.0"
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        resources:
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          requests:
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            cpu: 100m
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            memory: 128Mi
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          limits:
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            cpu: 500m
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            memory: 512Mi
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        livenessProbe:
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          httpGet:
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            path: /
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            port: 80
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          initialDelaySeconds: 10
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          periodSeconds: 5
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        readinessProbe:
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          httpGet:
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            path: /
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            port: 80
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          initialDelaySeconds: 5
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          periodSeconds: 3
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EOF

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# 创建Deployment
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kubectl apply -f nginx-deployment.yaml
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# 查看Deployment
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kubectl get deployment nginx-deployment
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# 查看ReplicaSet
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kubectl get replicaset
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# 查看Pod
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kubectl get pods -l app=nginx -o wide
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# 查看详细信息
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kubectl describe deployment nginx-deployment

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cat > nginx-service.yaml <<EOF
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apiVersion: v1
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kind: Service
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metadata:
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  name: nginx-service
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spec:
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  type: NodePort
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  selector:
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    app: nginx
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  ports:
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  - port: 80
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    targetPort: 80
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    nodePort: 30080
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EOF
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kubectl apply -f nginx-service.yaml
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# 测试访问
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curl http://192.168.100.21:30080

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# 如果还没有v2镜像，需要先构建（参考第四章）
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docker images | grep nginx-php

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# 方法1：修改YAML文件
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sed -i 's/nginx-php:v1/nginx-php:v2/' nginx-deployment.yaml
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sed -i 's/v1.0/v2.0/' nginx-deployment.yaml
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# 添加更新记录
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kubectl annotate deployment/nginx-deployment \
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  kubernetes.io/change-cause="升级到v2版本"
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# 应用更新
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kubectl apply -f nginx-deployment.yaml
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# 方法2：直接使用命令（更快）
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kubectl set image deployment/nginx-deployment \
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  nginx=reg.westos.org/library/nginx-php:v2
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kubectl annotate deployment/nginx-deployment \
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  kubernetes.io/change-cause="升级到v2版本"

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# 终端1：监控更新状态
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kubectl rollout status deployment/nginx-deployment
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# 终端2：监控Pod变化
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kubectl get pods -l app=nginx -w
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# 终端3：监控ReplicaSet
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kubectl get replicaset -w

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# 查看所有Pod的镜像版本
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kubectl get pods -l app=nginx -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[0].image}{"\n"}{end}'
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# 访问应用验证
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curl http://192.168.100.21:30080 | grep Version
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# 输出：Nginx-PHP - Version: v2.0
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# 查看历史版本
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kubectl rollout history deployment/nginx-deployment

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# 假设我们发现v2版本有严重bug
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# 查看当前版本
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kubectl rollout history deployment/nginx-deployment
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# REVISION  CHANGE-CAUSE
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# 1         创建初始版本
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# 2         升级到v2版本

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# 回滚到上一个版本（v1）
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kubectl rollout undo deployment/nginx-deployment
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# 或者回滚到指定版本
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kubectl rollout undo deployment/nginx-deployment --to-revision=1
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# 监控回滚过程
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kubectl rollout status deployment/nginx-deployment

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# 查看Pod镜像
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kubectl get pods -l app=nginx -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[0].image}{"\n"}{end}'
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# 应该显示：reg.westos.org/library/nginx-php:v1
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# 访问应用验证
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curl http://192.168.100.21:30080 | grep Version
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# 输出：Nginx-PHP Container（v1版本）
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# 查看历史（注意版本号变化）
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kubectl rollout history deployment/nginx-deployment
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# REVISION  CHANGE-CAUSE
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# 2         升级到v2版本
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# 3         回滚到v1版本

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# 当前3个副本，扩容到10个
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kubectl scale deployment/nginx-deployment --replicas=10
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# 观察扩容过程
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kubectl get pods -l app=nginx -w
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# 查看Deployment状态
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kubectl get deployment nginx-deployment
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# NAME                READY   UP-TO-DATE   AVAILABLE   AGE
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# nginx-deployment    10/10   10           10          5m
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# 查看Pod分布
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kubectl get pods -l app=nginx -o wide | awk '{print $7}' | sort | uniq -c
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#   5 node1
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#   5 node2

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# 流量下降，缩减到2个副本
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kubectl scale deployment/nginx-deployment --replicas=2
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# 观察缩容过程
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kubectl get pods -l app=nginx -w
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# 验证服务仍可访问
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for i in {1..10}; do curl -s http://192.168.100.21:30080 | grep Hostname; done
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# 虽然只有2个Pod，但Service会轮询负载均衡

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# 恢复到3个副本
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kubectl scale deployment/nginx-deployment --replicas=3

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# 下载配置文件
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wget https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml -O metrics-server.yaml
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# 修改配置（添加参数）
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vi metrics-server.yaml
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# 找到Deployment的containers.args部分，添加：
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# - --kubelet-insecure-tls
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# - --kubelet-preferred-address-types=InternalIP
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# 完整示例：
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spec:
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  containers:
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  - args:
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    - --cert-dir=/tmp
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    - --secure-port=4443
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    - --kubelet-preferred-address-types=InternalIP
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    - --kubelet-use-node-status-port
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    - --metric-resolution=15s
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    - --kubelet-insecure-tls  # 添加这行
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    image: registry.k8s.io/metrics-server/metrics-server:v0.6.4
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    name: metrics-server

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kubectl apply -f metrics-server.yaml
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# 等待Metrics Server就绪
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kubectl get pods -n kube-system | grep metrics-server
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kubectl wait --for=condition=ready pod -l k8s-app=metrics-server -n kube-system --timeout=300s
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# 验证（需要等待1-2分钟收集数据）
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sleep 60
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kubectl top nodes
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kubectl top pods

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$ kubectl top nodes
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NAME     CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
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master   234m         11%    1456Mi          38%
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node1    156m         7%     1123Mi          29%
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node2    145m         7%     1089Mi          28%
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$ kubectl top pods
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NAME                               CPU(cores)   MEMORY(bytes)
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nginx-deployment-7d64c8b9f5-abc   1m           15Mi
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nginx-deployment-7d64c8b9f5-def   1m           14Mi
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nginx-deployment-7d64c8b9f5-ghi   1m           16Mi

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# 修改deployment.yaml，确保有resources配置
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vi nginx-deployment.yaml
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# 确认包含resources：
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    resources:
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      requests:
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        cpu: 100m
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        memory: 128Mi
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      limits:
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        cpu: 500m
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        memory: 512Mi
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# 重新应用
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kubectl apply -f nginx-deployment.yaml

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cat > nginx-hpa.yaml <<EOF
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apiVersion: autoscaling/v2
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kind: HorizontalPodAutoscaler
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metadata:
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  name: nginx-hpa
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spec:
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  scaleTargetRef:
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    apiVersion: apps/v1
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    kind: Deployment
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    name: nginx-deployment
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  minReplicas: 2
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  maxReplicas: 10
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  metrics:
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  - type: Resource
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    resource:
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      name: cpu
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      target:
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        type: Utilization
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        averageUtilization: 50
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EOF
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kubectl apply -f nginx-hpa.yaml
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# 查看HPA状态
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kubectl get hpa
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# NAME        REFERENCE                    TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
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# nginx-hpa   Deployment/nginx-deployment  2%/50%    2         10        2          10s

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# 创建压力测试Pod
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kubectl run load-generator \
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  --image=reg.westos.org/library/busybox:1.30.1 \
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  --restart=Never \
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  --rm -it -- sh -c \
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  "while true; do wget -q -O- http://nginx-service; done"
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# 在另一个终端监控HPA
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kubectl get hpa nginx-hpa -w
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# 在第三个终端监控Pod数量
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kubectl get pods -l app=nginx -w

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# 停止load-generator（Ctrl+C）
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# 等待自动缩容（约5分钟）
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kubectl get hpa nginx-hpa -w
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# 查看最终状态
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kubectl get deployment nginx-deployment
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kubectl get hpa nginx-hpa

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# 假设当前是v1，要更新到v2
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kubectl set image deployment/nginx-deployment \
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  nginx=reg.westos.org/library/nginx-php:v2

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# 在更新开始后立即暂停
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kubectl rollout pause deployment/nginx-deployment
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# 查看当前状态（可能有1-2个Pod已更新）
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kubectl get pods -l app=nginx -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[0].image}{"\n"}{end}'

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# 找到新版本Pod的IP
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NEW_POD_IP=$(kubectl get pods -l app=nginx -o jsonpath='{.items[0].status.podIP}')
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# 多次访问测试
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for i in {1..20}; do curl -s http://$NEW_POD_IP | grep Version; done
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# 通过Service访问（会看到新旧版本混合）
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for i in {1..20}; do curl -s http://192.168.100.21:30080 | grep Version; done

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# 如果新版本正常，恢复更新
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kubectl rollout resume deployment/nginx-deployment
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# 如果新版本有问题，回滚
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kubectl rollout undo deployment/nginx-deployment

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# === 创建和删除 ===
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kubectl apply -f deployment.yaml        # 创建/更新
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kubectl delete deployment <name>        # 删除
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kubectl delete -f deployment.yaml       # 通过文件删除
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# === 查看状态 ===
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kubectl get deployment                  # 列出所有Deployment
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kubectl get deployment <name>           # 查看特定Deployment
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kubectl get deployment <name> -o yaml   # 查看完整YAML
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kubectl describe deployment <name>      # 查看详细信息
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# === 更新操作 ===
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kubectl set image deployment/<name> <container>=<image>  # 更新镜像
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kubectl edit deployment <name>                           # 编辑配置
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kubectl patch deployment <name> -p '{json}'              # 部分更新
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# === 回滚操作 ===
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kubectl rollout status deployment/<name>              # 查看更新状态
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kubectl rollout history deployment/<name>             # 查看历史
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kubectl rollout undo deployment/<name>                # 回滚到上一版本
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kubectl rollout undo deployment/<name> --to-revision=2  # 回滚到指定版本
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kubectl rollout pause deployment/<name>               # 暂停更新
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kubectl rollout resume deployment/<name>              # 恢复更新
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# === 扩缩容 ===
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kubectl scale deployment/<name> --replicas=5          # 手动扩缩容
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kubectl autoscale deployment/<name> --min=2 --max=10 --cpu-percent=50  # 自动扩缩容
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# === 调试 ===
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kubectl logs deployment/<name>                        # 查看日志
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kubectl logs -f deployment/<name>                     # 实时日志
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kubectl exec -it deployment/<name> -- bash            # 进入容器