【K8s】K8s控制器——复制集和deployment

高效、可靠地管理多个相同的容器应用，实现应用的自动扩缩容、故障恢复和版本升级

1、复制集

如果某个 Pod 挂了（比如容器崩溃、节点宕机），ReplicaSet 会自动创建一个新的 Pod 替补，始终确保 Pod 数量 = 你定义的 replicas 值。

2、deployment

通过管理 ReplicaSet 来间接控制 Pod（你一般不直接操作 ReplicaSet，而是通过 Deployment 来操作）；
支持滚动更新（平滑升级镜像版本，不停机）
支持回滚（升级失败时快速回到旧版本）
支持扩缩容（一键调整 Pod 数量）
支持版本历史记录（查看每次变更，方便审计和回退）

#- 8.1 # 创建复制集

定义yaml文件，这是一种声明式编程

bash 复制代码

cat > rs.yml <<EOF
apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: nginxrstest
  labels:
    app: nginxrstest
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginxrstest
  template:
    metadata:
      labels:
        app: nginxrstest
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
          - name: http
            containerPort: 80
        imagePullPolicy: IfNotPresent
EOF

创建复制集

bash 复制代码

kubectl create -f rs.yml

查看复制集

bash 复制代码

kubectl get replicasets.apps,pods -o wide

删除复制集

bash 复制代码

kubectl delete replicasets nginxrstest

#- 8.2 #创建deployment

cat > deployment.yml <<EOF

apiVersion: apps/v1

kind: Deployment

metadata:

name: nginx-deployment

labels:

app: nginx

spec:

replicas: 3

selector:

matchLabels:

app: nginx

template:

metadata:

labels:

app: nginx

spec:

containers:

name: nginx

image: nginx

imagePullPolicy: IfNotPresent

ports:

containerPort: 80

EOF

kubectl create -f deployment.yml

kubectl get deployments.apps,replicasets.apps,pods -l app=nginx

#- 8.3 # 升级

kubectl set image deployments/nginx-deployment nginx=nginx:1.16.1 --record

kubectl rollout status deployment/nginx-deployment

kubectl get deployments.apps,replicasets.apps,pods -l app=nginx

#- 8.4 # 回滚

kubectl set image deployments/nginx-deployment nginx=nginx:1.161 --record

kubectl rollout status deployment/nginx-deployment

kubectl rollout history deployments/nginx-deployment

kubectl rollout history deployment.v1.apps/nginx-deployment --revision=3

kubectl rollout undo deployments/nginx-deployment --to-revision=2

kubectl rollout status deployment/nginx-deployment

kubectl get deployments.apps,replicasets.apps,pods -l app=nginx

#- 8.5 # 扩容

kubectl scale deployments/nginx-deployment --replicas=5

kubectl get deployments.apps,replicasets.apps,pods -l app=nginx

kubectl delete deployments.apps nginx-deployment

kubectl get deployments.apps,replicasets.apps,pods -l app=nginx