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【K8s】K8s控制器——复制集和deployment

news 2025/8/13 13:49:58

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

cat > rs.yml <<EOF
apiVersion: apps/v1
kind: ReplicaSet
metadata:name: nginxrstestlabels:app: nginxrstest
spec:replicas: 3selector:matchLabels:app: nginxrstesttemplate:metadata:labels:app: nginxrstestspec:containers:- name: nginximage: nginxports:- name: httpcontainerPort: 80imagePullPolicy: IfNotPresent
EOF

创建复制集

kubectl create -f rs.yml

查看复制集

kubectl get replicasets.apps,pods -o wide

删除复制集

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