kubectl 速查手册

资源对象文件

---
kind: Pod
apiVersion: v1
metadata:
  name: myweb
  labels:
    app: nginx
spec:
  containers:
  - name: webserver
    image: nginx
status: {}

annotate

# 更新资源所关联的注释信息
#-----------------------------------------#
[root@master k8s]# kubectl apply -f mypod.yaml --record
[root@master k8s]# kubectl get pod mypod -o custom-columns=podName:.metadata.name,annotations:.metadata.annotations."kubernetes\.io/change-cause"
podName   annotations
mypod     kubectl apply --filename=mypod.yaml --record=true
[root@master k8s]# kubectl annotate pods mypod kubernetes.io/change-cause='my description'
pod/mypod annotated
[root@master k8s]# kubectl get pod mypod -o custom-columns=podName:.metadata.name,annotations:.metadata.annotations."kubernetes\.io/change-cause"
podName   annotations
mypod     my description

api-resources

# 显示服务器上所支持的 API 资源
# -o wide 可以用来查询资源权限
#-----------------------------------------#
[root@master k8s]# kubectl api-resources -o wide
NAME         SHORTNAMES   APIVERSION       NAMESPACED   KIND         VERBS
pods         po           v1               true         Pod          [get list patch ...]
namespaces   ns           v1               false        Namespace    [create get ...]

api-versions

# 显示服务端所支持的 API 版本
#-----------------------------------------#
[root@master k8s]# kubectl api-versions
admissionregistration.k8s.io/v1
apps/v1
... ...
v1

apply

# 读取资源文件,将新的配置应用到资源上
#-----------------------------------------#
[root@master k8s]# kubectl apply -f mypod.yaml 
pod/mypod created
[root@master k8s]# sed 's,mypod,myweb,g' mypod.yaml |kubectl apply -f -
pod/myweb created
[root@master k8s]# kubectl get pods
NAME    READY   STATUS    RESTARTS   AGE
mypod   1/1     Running   0          36s
myweb   1/1     Running   0          4s

attach

# 连接一个正在运行的容器的启动进程
#-----------------------------------------#
[root@master k8s]# kubectl attach mypod -c linux
If you don't see a command prompt, try pressing enter.
10.244.219.64:44372: response:200

auth

# 检查授权信息
#-----------------------------------------#
[root@master k8s]# kubectl --kubeconfig=admin.conf auth can-i get pods 
yes
[root@master k8s]# kubectl --kubeconfig=auth.conf  auth can-i get pods 
no

autoscale

# 创建一个HPA控制器，对资源对象进行自动扩缩
#-----------------------------------------#
[root@master k8s]# kubectl apply -f myDeploy.yaml
deployment.apps/myweb created
[root@master k8s]# kubectl autoscale deployment myweb --min=1 --max=10 --cpu-percent=80
horizontalpodautoscaler.autoscaling/myweb autoscaled
[root@master k8s]# kubectl get horizontalpodautoscalers.autoscaling 
NAME    REFERENCE          TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
myweb   Deployment/myweb   10%/80%   1         10        1          27m
#-----------------------------------------#
---
apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
  name: myweb
spec:
  minReplicas: 1
  maxReplicas: 10
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: myweb
  targetCPUUtilizationPercentage: 80

certificate

# 修改证书资源
#-----------------------------------------#
[root@master k8s]# kubectl get certificatesigningrequests
NAME        AGE   REQUESTOR            CONDITION
csr-wsfz7   8s    system:node:master   Pending
[root@master k8s]# kubectl certificate approve csr-wsfz7
[root@master k8s]# kubectl get certificatesigningrequests
NAME        AGE   REQUESTOR            CONDITION
csr-wsfz7   86s   system:node:master   Approved,Issued

cluster-info

# 显示集群信息
#-----------------------------------------#
[root@master k8s]# kubectl cluster-info 
Kubernetes control plane is running at https://192.168.1.10:6443
CoreDNS is running at https://192.168.1.10:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

completion

# 根据已经给出的 Shell 输出  补全代码
#-----------------------------------------#
[root@master k8s]# source  8080
Forwarding from 0.0.0.0:80 -> 80
#-----------------------------------------#
[root@master local]# curl http://master:8080
hello world.

proxy

# 运行一个 kubernetes API 服务器代理
#-----------------------------------------#
[root@master k8s]# kubectl proxy --port=80
Starting to serve on 127.0.0.1:80
#-----------------------------------------#
[root@master k8s]# curl http://127.0.0.1/version
{
  "major": "1",
  "minor": "22",
  "gitVersion": "v1.22.5",
  "gitCommit": "c92036820499fedefec0f847e2054d824aea6cd1",
  "gitTreeState": "clean",
  "buildDate": "2021-10-27T18:35:25Z",
  "goVersion": "go1.16.9",
  "compiler": "gc",
  "platform": "linux/amd64"
}

replace

# 基于文件名或标准输入替换资源
#-----------------------------------------#
[root@master k8s]# kubectl replace --force -f mypod.yaml 
pod "mypod" deleted
pod/mypod replaced

rollout

set

# 为资源对象设置功能特性

#-----------------------------------------#

[root@master k8s]# kubectl set env pods --all --list

# Pod mypod, container linux

[root@master k8s]# kubectl set env deployment/myweb myEnv=prod

deployment.apps/myweb env updated

[root@master k8s]# kubectl exec -i -t myweb-6c645646c9-pqjc7 -- sh -c 'echo ${myEnv}'

prod

[root@master k8s]# kubectl get deployments.apps myweb -o wide

NAME    READY   AGE   CONTAINERS   IMAGES                     SELECTOR

myweb   1/1     25s   httpd        registry:5000/myos:httpd   app=apache

[root@master k8s]# kubectl set image deployment/myweb httpd=registry:5000/myos:nginx

deployment.apps/myweb image updated

[root@master k8s]# kubectl get deployments.apps myweb -o wide

NAME    READY   AGE   CONTAINERS   IMAGES                     SELECTOR

myweb   1/1     45s   httpd        registry:5000/myos:nginx   app=apache

taint

# 在一个或者多个节点上更新污点配置

#-----------------------------------------#

[root@master k8s]# kubectl get nodes -o custom-columns=NodeName:.metadata.name,Taints:.spec.taints

NodeName    Taints

master      [map[effect:NoSchedule key:node-role.kubernetes.io/master]]

node-0001   

[root@master k8s]# kubectl taint node node-0001 k=v:PreferNoSchedule

node/node-0001 tainted

[root@master k8s]# kubectl get nodes -o custom-columns=NodeName:.metadata.name,Taints:.spec.taints

NodeName    Taints

master      [map[effect:NoSchedule key:node-role.kubernetes.io/master]]

node-0001   [map[effect:PreferNoSchedule key:k value:v]]

[root@master k8s]# kubectl taint node node-0001 k-

node/node-0001 untainted

[root@master k8s]# kubectl get nodes -o custom-columns=NodeName:.metadata.name,Taints:.spec.taints

NodeName    Taints

master      [map[effect:NoSchedule key:node-role.kubernetes.io/master]]

# 管理资源的上线
#-----------------------------------------#
[root@master k8s]# kubectl rollout history deployment 
deployment.apps/myweb 
REVISION  CHANGE-CAUSE
1         httpd.v1
2         httpd.v2
[root@master k8s]# kubectl rollout undo deployment myweb --to-revision=1
deployment.apps/myweb rolled back
[root@master k8s]# kubectl rollout history deployment 
deployment.apps/myweb 
REVISION  CHANGE-CAUSE
2         httpd.v2
3         httpd.v1
run

# 在集群中使用指定镜像启动容器
#-----------------------------------------#
[root@master k8s]# kubectl run mypod --image=registry:5000/myos:httpd
#-----------------------------------------#
---
apiVersion: v1
kind: Pod
metadata:
  labels:
    run: mypod
  name: mypod
spec:
  containers:
  - image: registry:5000/myos:httpd
    name: mypod
  restartPolicy: Always
scale

# 为可扩充资源设置一个新副本数量
#-----------------------------------------#
[root@master k8s]# kubectl apply -f myDeploy.yaml
deployment.apps/myweb created
[root@master ~]# kubectl get deployments.apps 
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
myweb   1/1     1            1           21m
[root@master ~]# kubectl scale deployment myweb --replicas=3
deployment.apps/myweb scaled
[root@master ~]# kubectl get deployments.apps 
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
myweb   3/3     3            3           21m

top

# 显示资源（CPU /内存/存储）使用率
#-----------------------------------------#
[root@master k8s]# kubectl top nodes
NAME        CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
master      90m          4%     1210Mi          14%       
node-0001   45m          2%     931Mi           11%       
[root@master k8s]# kubectl top pods
NAME                     CPU(cores)   MEMORY(bytes)   
mypod                    5m           8Mi
[root@master k8s]# 

uncordon

# 解除（cordon、drain）资源不可调度标记
#-----------------------------------------#
[root@master k8s]# kubectl get nodes
NAME        STATUS                     ROLES    AGE   VERSION
master      Ready                      master   15h   v1.22.5
node-0001   Ready,SchedulingDisabled   node     15h   v1.22.5
[root@master k8s]# kubectl uncordon node-0001 
node/node-0001 uncordoned
[root@master k8s]# kubectl get nodes
NAME        STATUS   ROLES    AGE   VERSION
master      Ready    master   15h   v1.22.5
node-0001   Ready    node     15h   v1.22.5

version

# 显示客户端和服务器的版本信息
#-----------------------------------------#
[root@master k8s]# kubectl version -o yaml
clientVersion:
  buildDate: "2021-10-27T18:41:28Z"
  compiler: gc
  gitCommit: c92036820499fedefec0f847e2054d824aea6cd1
  gitTreeState: clean
  gitVersion: v1.22.5
  goVersion: go1.16.9
  major: "1"
  minor: "22"
  platform: linux/amd64
serverVersion:
  buildDate: "2021-10-27T18:35:25Z"
  compiler: gc
  gitCommit: c92036820499fedefec0f847e2054d824aea6cd1
  gitTreeState: clean
  gitVersion: v1.22.5
  goVersion: go1.16.9
  major: "1"
  minor: "22"
  platform: linux/amd64
wait
# 等待一个或多个资源达到某种状态
#-----------------------------------------#
---
kind: Pod
apiVersion: v1
metadata:
  name: mypod
spec:
  terminationGracePeriodSeconds: 0
  initContainers:
  - name: myinit
    image: registry:5000/busybox:latest
    imagePullPolicy: IfNotPresent
    command: ["sleep", "10"]
  containers:
  - name: linux
    image: registry:5000/busybox:latest
    imagePullPolicy: IfNotPresent
    command: ["sh", "-c"]
    args:
    - |
      echo "hello world !!!" >/var/www/index.html
      httpd -v -f -p 0.0.0.0:80 -h /var/www
  restartPolicy: Always
#-----------------------------------------#
[root@master k8s]# kubectl replace --force -f mypod.yaml 
pod "mypod" deleted
pod/mypod replaced
[root@master k8s]# time kubectl wait --for=condition=Ready pod/mypod
pod/mypod condition met
real    0m10.335s
user    0m0.034s
sys 0m0.008s

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