创建nginx的描述文件

# 基于deployment创建3个pod，加上标签。
apiVersion: apps/v1      
kind: Deployment         
metadata:
  name: nginx
spec:
  replicas: 2                    
  selector:              
    matchLabels:
      app: nginx
  template:              
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:latest
        name: container-0
        resources:
          limits:
            cpu: 100m
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 200Mi

创建并记录版本

# 基于上述yaml描述文件创建pod
kubectl create -f nginx-pod.yml --record
Flag --record has been deprecated, --record will be removed in the future
deployment.apps/nginx created


# 方法2 基于命令行创建pod
kubectl create deployment redis --image=docker.io/library/nginx:latest


# 查看扩容后的pod结果
kubectl get pods -owide
NAME                     READY   STATUS    RESTARTS   AGE   IP               NODE         NOMINATED NODE   READINESS GATES
nginx-7b57694cbb-9r9rh   1/1     Running   0          84s   172.20.217.118   10.0.0.204   <none>           <none>
nginx-7b57694cbb-l8x6g   1/1     Running   0          84s   172.20.139.166   10.0.0.203   <none>           <none>


# 查看rs控制器的信息
kubectl get rs
NAME               DESIRED   CURRENT   READY   AGE
nginx-7b57694cbb   2         2         2       70s


# 查看当前回滚历史记录值
kubectl rollout history deployment nginx 
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
1         kubectl create --filename=ngninx-pod.yml --record=true

创建一个service

# 由于是测试环境，为了省事，这里没有使用名称空间
# 集群内，开启一个固定死的ip，svc的ip地址，负载均衡代理一组pod
apiVersion: v1
kind: Service
metadata:
  name: svc-nginx        # Service的名称 ，svc  ip，dns
spec:
  selector:          # Label Selector，选择包含app=nginx标签的Pod
    app: nginx
  ports:
  - name: service0
    targetPort: 80   # Pod的端口
    port: 80         # Service对外暴露的端口，也就是ClusterIP的port
    protocol: TCP    # 转发协议类型，支持TCP和UDP
    # Service的类型


# 创建svc
kubectl create -f svc-test.yml 
service/svc-nginx created



# 查看svc
kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.68.0.1       <none>        443/TCP   2d
svc-nginx    ClusterIP   10.68.235.222   <none>        80/TCP    5s


# 查看svc详细信息
kubectl describe svc


# 测试访问svc查看当前nginx版本
curl -I 10.68.235.222
HTTP/1.1 200 OK
Server: nginx/1.21.5

模拟服务发版，修改nginx版本

# 查看当前回滚历史记录
kubectl rollout history deployment nginx 
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
1         kubectl create --filename=ngninx-pod.yml --record=true


# 方法1 使用edit编辑，更新nginx版本(nginx:1.14.0)
kubectl edit deployments.apps nginx 

# 修改如下
spec:
      containers:
      - image: nginx:1.14.0
        imagePullPolicy: Always
        name: container-0
        resources:
          limits:


# 方法2 命令行更新
kubectl set image deploy nginx container=nginx:0:1.14.0 --record


# 监测滚动更新状态
kubectl get pods -w
NAME                     READY   STATUS              RESTARTS   AGE
nginx-65cbd4cb47-6l59c   0/1     ContainerCreating   0          10s
nginx-8c99db597-46pmb    1/1     Running             0          2m34s
nginx-8c99db597-xdvzm    1/1     Running             0          2m12s
nginx-65cbd4cb47-6l59c   1/1     Running             0          45s
nginx-8c99db597-46pmb    1/1     Terminating         0          3m10s
nginx-65cbd4cb47-7xg6z   0/1     Pending             0          0s
nginx-65cbd4cb47-7xg6z   0/1     Pending             0          0s
nginx-65cbd4cb47-7xg6z   0/1     Pending             0          0s
nginx-65cbd4cb47-7xg6z   0/1     ContainerCreating   0          0s
nginx-8c99db597-46pmb    0/1     Terminating         0          3m11s
nginx-8c99db597-46pmb    0/1     Terminating         0          3m11s
nginx-8c99db597-46pmb    0/1     Terminating         0          3m12s
nginx-8c99db597-46pmb    0/1     Terminating         0          3m12s
nginx-65cbd4cb47-7xg6z   1/1     Running             0          6s
nginx-8c99db597-xdvzm    1/1     Terminating         0          2m55s
nginx-8c99db597-xdvzm    1/1     Terminating         0          2m55s
nginx-8c99db597-xdvzm    1/1     Terminating         0          2m55s
nginx-65cbd4cb47-7xg6z   1/1     Running             0          11s


# 查看回滚状态
kubectl rollout status deployment nginx 
deployment "nginx" successfully rolled out


# 查看重新生成的pod
kubectl get pods 
NAME                     READY   STATUS    RESTARTS   AGE
nginx-65cbd4cb47-6l59c   1/1     Running   0          73s
nginx-65cbd4cb47-7xg6z   1/1     Running   0          27s


# 测试访问(此时的nginx版本为1.14.0)
curl -I 10.68.235.222
HTTP/1.1 200 OK
Server: nginx/1.14.0


# 再次查看回滚历史记录
# 此时刚刚修改的nginx版本信息被记录了
kubectl rollout history deployment nginx 
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
1         kubectl create --filename=ngninx-pod.yml --record=true
2         kubectl create --filename=ngninx-pod.yml --record=true


# 查看具体版本的，镜像信息(--revision=版本号)
kubectl rollout history deployment nginx --revision=3


# 方法1 回到上一个nginx版本nginx:latest
kubectl rollout undo deployment nginx


# 方法2 指定回滚到某个版本
kubectl rollout undo  deployment nginx --to-revision=1


# 再次测试访问
curl -I 10.68.235.222
HTTP/1.1 200 OK
Server: nginx/1.21.5

拓展 

# 同时查看k8s多个资源小技巧
kubectl get deployments.apps,pods,rs


# 获得yaml配置
# 创建deployment的命令，加上`--dry-run -o yaml`
# --dry-run代表这条命令不会实际在K8s执行，-o yaml是会将试运行结果以yaml的格式打印出来
kubectl create deployment nginx --image=nginx --dry-run -o yaml       



动态、扩、缩容POD

# 扩容副本数为4
kubectl -n <namespace> scale --replicas=4 rs nginx-rs


# 缩容pod数改为2
kubectl -n <namespace> scale --replicas=2 rs nginx-rs



Node管理

# 禁止pod调度到该节点上
kubectl cordon <node name> --delete-emptydir-data --ignore-daemonsets

# 恢复pod正常调度
kubectl uncordon <node name>

# 驱逐该节点上的所有pod
kubectl drain <node name>
该命令会删除该节点上的所有Pod（DaemonSet除外），在其他node上重新启动它们，通常该节点需要维护时使用该命令。直接使用该命令会自动调用kubectl cordon <node>命令。当该节点维护完成，启动了kubelet后，再使用kubectl uncordon <node>即可将该节点添加到kubernetes集群中