kubectl常用命令（全局篇）

格式 -o

[cmd] -o json|yaml|wide

如：输出json格式

kubectl get ns ingress-nginx -o json

获取基本信息get

#查看集群基本信息

kubectl get cs|pods|nodes|ns|svc|rc|deployments

kubectl get cs

kubectl get pods

kubectl get nodes

kubectl get ns

kubectl get svc

kubectl get rc

kubectl get deployments

查看详细信息 describe|logs

查看描述性信息describe

kubectl describe node|pod|deployment node-name|pod-name|deployment-name

kubectl describe node master01

[root@master01 ~]# kubectl  describe node master01
Name:               master01
Roles:              control-plane,master
Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/os=linux
                    kubernetes.io/arch=amd64
                    kubernetes.io/hostname=master01
                    kubernetes.io/os=linux
                    node-role.kubernetes.io/control-plane=
                    node-role.kubernetes.io/master=
                    node.kubernetes.io/exclude-from-external-load-balancers=
Annotations:        flannel.alpha.coreos.com/backend-data: {"VNI":1,"VtepMAC":"a6:4d:30:a1:32:aa"}
                    flannel.alpha.coreos.com/backend-type: vxlan
                    flannel.alpha.coreos.com/kube-subnet-manager: true
                    flannel.alpha.coreos.com/public-ip: 192.168.182.127
                    kubeadm.alpha.kubernetes.io/cri-socket: /var/run/dockershim.sock
                    management.cattle.io/pod-limits: {"memory":"340Mi"}
                    management.cattle.io/pod-requests: {"cpu":"950m","memory":"290Mi","pods":"9"}
                    node.alpha.kubernetes.io/ttl: 0
                    volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp:  Fri, 22 Dec 2023 23:20:54 +0800
Taints:             node-role.kubernetes.io/master:NoSchedule
Unschedulable:      false
Lease:
  HolderIdentity:  master01
  AcquireTime:     <unset>
  RenewTime:       Fri, 05 Jan 2024 22:28:05 +0800
Conditions:
  Type                 Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
  ----                 ------  -----------------                 ------------------                ------                       -------
  NetworkUnavailable   False   Fri, 05 Jan 2024 18:35:20 +0800   Fri, 05 Jan 2024 18:35:20 +0800   FlannelIsUp                  Flannel is running on this node
  MemoryPressure       False   Fri, 05 Jan 2024 22:25:12 +0800   Wed, 03 Jan 2024 22:40:27 +0800   KubeletHasSufficientMemory   kubelet has sufficient memory available
  DiskPressure         False   Fri, 05 Jan 2024 22:25:12 +0800   Wed, 03 Jan 2024 22:40:27 +0800   KubeletHasNoDiskPressure     kubelet has no disk pressure
  PIDPressure          False   Fri, 05 Jan 2024 22:25:12 +0800   Wed, 03 Jan 2024 22:40:27 +0800   KubeletHasSufficientPID      kubelet has sufficient PID available
  Ready                True    Fri, 05 Jan 2024 22:25:12 +0800   Wed, 03 Jan 2024 22:40:27 +0800   KubeletReady                 kubelet is posting ready status
Addresses:
  InternalIP:  192.168.182.127
  Hostname:    master01
Capacity:
  cpu:                2
  ephemeral-storage:  17394Mi
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             3990120Ki
  pods:               110
Allocatable:
  cpu:                2
  ephemeral-storage:  16415037823
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             3887720Ki
  pods:               110
System Info:
  Machine ID:                 b5c63e049a3344f9a3bb0d4147e8237d
  System UUID:                45da4d56-daf6-0055-e7a7-b414b6f8c4ac
  Boot ID:                    960d557f-4c01-48fd-b67d-ed3ce46a2935
  Kernel Version:             5.4.265-1.el7.elrepo.x86_64
  OS Image:                   CentOS Linux 7 (Core)
  Operating System:           linux
  Architecture:               amd64
  Container Runtime Version:  docker://24.0.7
  Kubelet Version:            v1.23.1
  Kube-Proxy Version:         v1.23.1
PodCIDR:                      10.244.0.0/24
PodCIDRs:                     10.244.0.0/24
Non-terminated Pods:          (9 in total)
  Namespace                   Name                                     CPU Requests  CPU Limits  Memory Requests  Memory Limits  Age
  ---------                   ----                                     ------------  ----------  ---------------  -------------  ---
  cattle-system               cattle-cluster-agent-694c664f67-m26qw    0 (0%)        0 (0%)      0 (0%)           0 (0%)         8d
  kube-flannel                kube-flannel-ds-554jc                    100m (5%)     0 (0%)      50Mi (1%)        0 (0%)         10d
  kube-system                 coredns-6d8c4cb4d-8qkwj                  100m (5%)     0 (0%)      70Mi (1%)        170Mi (4%)     13d
  kube-system                 coredns-6d8c4cb4d-kbj92                  100m (5%)     0 (0%)      70Mi (1%)        170Mi (4%)     13d
  kube-system                 etcd-master01                            100m (5%)     0 (0%)      100Mi (2%)       0 (0%)         13d
  kube-system                 kube-apiserver-master01                  250m (12%)    0 (0%)      0 (0%)           0 (0%)         13d
  kube-system                 kube-controller-manager-master01         200m (10%)    0 (0%)      0 (0%)           0 (0%)         13d
  kube-system                 kube-proxy-r2l4s                         0 (0%)        0 (0%)      0 (0%)           0 (0%)         13d
  kube-system                 kube-scheduler-master01                  100m (5%)     0 (0%)      0 (0%)           0 (0%)         13d
Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.)
  Resource           Requests    Limits
  --------           --------    ------
  cpu                950m (47%)  0 (0%)
  memory             290Mi (7%)  340Mi (8%)
  ephemeral-storage  0 (0%)      0 (0%)
  hugepages-1Gi      0 (0%)      0 (0%)
  hugepages-2Mi      0 (0%)      0 (0%)
Events:              <none>

kubectl describe pod my-dep-7cb9c979b4-tp6s7

kubectl describe deployment my-dep

查看运行日志

kubectl logs?[-f] <Pod_name>? -n? <namespace> #如果有-f ，这是持续输出

kubectl logs kube-flannel-ds-554jc -n kube-flannel

解释说明explain

kubectl explain rs

kubectl explain deploy

操作 create|run|delete|exec|exit

创建create

kubectl create deployment web-app --image=nginx

kubectl create -f deployment.yaml #根据指定文件创建

例如一个最简单的yaml文件

apiVersion: v1
kind: Pod
metadata:
  name: demo
  labels:
    app: nginx
spec:
  containers:
  - name: nginx
    image: nginx

删除delete

kubectl delete deployment web-app

运行run

kubectl run nginx --image=nginx

kubectl run nginx --image=nginx --port=8088

删除 delete

kubectl delete

kubectl delete ?pod demo

kubectl delete pods --all #据说是清空所有pod，没试过，大家看情况尝试

注意：如果是创建了deployment，会自动创建对应的pod,此时手动删除pod，系统会自动再启动pod，若想清除，需要删除创建的deployment，就如下面的例子

删除指定pod，看似删掉了，删除之后会自动创建

kubectl delete pod <pod_name>

kubectl delete pod web-app-5c7fd9d786-zwzj7

进入pod? exec

kubectl exec -it ?cattle-cluster-agent-694c664f67-m26qw -n cattle-system bash

退出pod exit

exit

资源查看? top

kubectl top [flags] [options]

kubectl top pod

对应的api服务没有开启，则需要开启对应的服务。

问题解决需要参照如下链接去安装服务：

Releases · kubernetes-sigs/metrics-server · GitHub

kubectl apply -f components.yaml

部署完毕之后，发现有新的问题，也许是版本问题，待后续解决

kubectl top node #情况同上

暴漏 expose

将已经有的资源，创建一个service服务，并且暴露端口让外部可以访问

kubectl expose deployment nginx --port=88 --type=NodePort --target-port=80 --name=nginx-service

设定 set?

资源设定 resources

# 将deployment的nginx容器cpu限制为“200m”，将内存设置为“512Mi”

kubectl set resources deployment nginx -c=nginx --limits=cpu=200m,memory=512Mi

# 设置所有nginx容器中 Requests和Limits

kubectl set resources deployment nginx --limits=cpu=200m,memory=512Mi --requests=cpu=100m,memory=256Mi

# 删除nginx中容器的计算资源值

kubectl set resources deployment nginx --limits=cpu=0,memory=0 --requests=cpu=0,memory=0

单位m:CPU的计量单位叫毫核(m)。一个节点的CPU核心数量乘以1000,得到的就是节点总的CPU总数量。如,一个节点有两个核,那么该节点的CPU总量为2000m

镜像设定 images

给特定的容器设置镜像

kubectl set image deployment/nginx busybox=busybox nginx=nginx:1.9.1

回滚 rollout

查看指定资源的历史

kubectl rollout history deployment/my-dep

kubectl rollout history daemonset/kube-flannel-ds -n kube-flannel

回滚到上一个版本

kubectl rollout undo deployment/nginx

回滚到指定版本

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

查看回滚状态

kubectl rollout status daemonset/kube-flannel-ds -n kube-flannel

暂停 pause

kubectl rollout pause deployment my-dep #暂停

恢复 resume

kubectl rollout resume deployment my-dep #恢复