kubectl命令¶

本教程使用的版本是k8s-v1.24.2 - 官网文档

kubectl的命令语法可总结成下面格式 - kubectl [command] [TYPE] [NAME] [flags] - commmand：指定要对一个或多个资源执行的操作，例如 create、get、describe、delete - TYPE：指定资源类型。资源类型不区分大小写，可以指定单数、复数或缩写形式。例如，node，ns(namespace的缩写)，pod - NAME：指定资源的名称。名称区分大小写。如果省略名称，则显示所有资源的详细信息。例如：kubectl get pods - flags：指定可选的参数。例如，可以使用 -s 或 --server 参数指定 Kubernetes API 服务器的地址和端口。

1 create¶

功能：创建资源

1.1 deployment¶

语法：kubectl create deployment NAME --image=image -- [COMMAND] [args...]
- --image=image：指定镜像
- --replicas=num或-r num：指定副本数量
- --port：容器暴露的端口
示例：创建deployment资源

[root@master ~]# kubectl create deployment my-nginx --image=nginx
deployment.apps/my-nginx created
[root@master ~]# kubectl get pod
NAME                        READY   STATUS              RESTARTS   AGE
my-nginx-7cddc5685c-w44cd   0/1     ContainerCreating   0          14s
[root@master ~]# kubectl get pod -o wide
NAME                        READY   STATUS    RESTARTS   AGE   IP             NODE    NOMINATED NODE   READINESS GATES
my-nginx-7cddc5685c-w44cd   1/1     Running   0          18s   10.244.104.5   node2   <none>           <none>
[root@master ~]# kubectl get deploy
NAME       READY   UP-TO-DATE   AVAILABLE   AGE
my-nginx   1/1     1            1           66s
[root@master ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   3d18h

创建了deployment资源，直接删除pod是不能达到目的的，需要删除deployment，才能删除pod

# 删除后，pod没有消失，而在重建
[root@master ~]# kubectl delete pod my-nginx-7cddc5685c-w44cd
pod "my-nginx-7cddc5685c-w44cd" deleted
[root@master ~]# kubectl get pod
NAME                        READY   STATUS              RESTARTS   AGE
my-nginx-7cddc5685c-wqtmr   0/1     ContainerCreating   0          7s

1.2 service¶

语法：kubectl create TYPE NAME [--tcp=<port>:<targetPort>] [--dry-run=server|client|none]
- TYOE：服务类型
  - clusterip：集群IP，k8s集群间可以访问
  - externalname
  - loadbalancer
  - nodeport：节点ip，集群外部可以通过任一台k8s集群主机ip来访问
- NAME：服务名称
- --tcp=<port>:<targetPort>：暴露的tcp端口
示例：创建clusterip

[root@master k8s-yaml]# kubectl create service clusterip nginx --tcp=8080:80
service/nginx created
[root@master k8s-yaml]# kubectl get svc
NAME         TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP    17d
nginx        ClusterIP   10.98.35.251   <none>        8080/TCP   7s

2 get¶

功能：获取资源信息
flag:
- -A：显示所有命令空间资源
- -f 文件名：显示yaml文件里指定的资源
示例：

[root@master ~]# kubectl get pod 
NAME                        READY   STATUS    RESTARTS        AGE
my-nginx-7cddc5685c-wqtmr   1/1     Running   1 (4h41m ago)   5h11m
[root@master ~]# kubectl get pod -A
NAMESPACE     NAME                                       READY   STATUS    RESTARTS        AGE
default       my-nginx-7cddc5685c-wqtmr                  1/1     Running   1 (4h40m ago)   5h11m
kube-system   calico-kube-controllers-6766647d54-hbshz   1/1     Running   3 (4h40m ago)   3d23h
...省略...
kube-system   kube-scheduler-master                      1/1     Running   5 (4h40m ago)   3d23h

3 run¶

功能：指定镜像运行一个pod
flag：
- -it：用于进去容器，分配一个TTY，保持stdin打开
- --image：镜像名
- --env：传给容器的环境变量
- --port：容器暴露的端口
- --labels：pod标签
- --restart=[Always, OnFailure, Never]：容器exit状态的重启策略
示例：运行一个nginx服务 pod

[root@master ~]# kubectl run nginx --image=nginx
pod/nginx created
[root@master ~]# kubectl get pod -o wide
NAME    READY   STATUS    RESTARTS   AGE   IP             NODE    NOMINATED NODE   READINESS GATES
nginx   1/1     Running   0          18s   10.244.104.6   node2   <none>           <none

4 exec¶

进入Pod 中的容器或执行命令
语法形式：

# 从 Pod <pod-name> 中获取运行 'date' 的输出。默认情况下，输出来自第一个容器。
kubectl exec <pod-name> -- date

# 运行输出 'date' 获取在 Pod <pod-name> 中容器 <container-name> 的输出。
kubectl exec <pod-name> -c <container-name> -- date

# 获取一个交互 TTY 并在 Pod  <pod-name> 中运行 /bin/bash。默认情况下，输出来自第一个容器。
kubectl exec -it <pod-name> -- /bin/bash

5 attach¶

功能：附着在running状态的容器上
语法：kubectl attach (POD | TYPE/NAME) -c CONTAINER
- -c CONTAINER：指定具体的容器，默认是pod的第一个容器
- -it：
示例1:attach nginx后，访问nginx，将会输出信息

[root@master ~]# kubectl attach nginx
If you don't see a command prompt, try pressing enter.

192.168.211.22 - - [25/Jul/2022:10:54:25 +0000] "GET / HTTP/1.1" 200 615 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36" "-"
2022/07/25 10:54:25 [error] 32#32: *1 open() "/usr/share/nginx/html/favicon.ico" failed (2: No such file or directory), client: 192.168.211.22, server: localhost, request: "GET /favicon.ico HTTP/1.1", host: "192.168.211.22:30987", referrer: "http://192.168.211.22:30987/"
192.168.211.22 - - [25/Jul/2022:10:54:25 +0000] "GET /favicon.ico HTTP/1.1" 404 555 "http://192.168.211.22:30987/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36" "-"

6 describe¶

不指定具体的资源名，默认显示所有的资源

功能：显示资源详细信息
语法：kubectl describe (-f FILENAME | TYPE [NAME_PREFIX | -l label] | TYPE/NAME)
示例

# 显示名为 <pod-name> 的 Pod 的详细信息。
kubectl describe nodes <node-name>

# 显示名为 <pod-name> 的 Pod 的详细信息。
kubectl describe pods/<pod-name>

# 显示由名为 <rc-name> 的副本控制器管理的所有 Pod 的详细信息。
# 记住：副本控制器创建的任何 Pod 都以副本控制器的名称为前缀。
kubectl describe pods <rc-name>

# 描述所有的 Pod
kubectl describe pods

7 expose¶

功能：将资源公开为一个新的 Kubernetes 服务
语法：kubectl expose (-f FILENAME | TYPE NAME) [--port=port] [--protocol=TCP|UDP|SCTP] [--target-port=number-or-name] [--name=name] [--external-ip=external-ip-of-service] [--type=type]
flag
- TYPE NAME：指定资源类型和资源名称，比如pod nginx
- --port：pod内端口
- --target-port：service端口
- --name：创建的service名
- --protocol=[TCP,UDP]：网络协议，默认TCP
- --type=[ClusterIP, NodePort, LoadBalancer, ExternalName]：service类型，默认是ClusterIP，只能k8s集群内访问
- -f 文件名：通过yaml文件指定要公开的资源
示例：把pod nginx中80端口绑定到service的8000端口，通过service IP+port可以访问nginx

[root@master ~]# kubectl expose pod nginx --name svc-nginx --port=8000 --target-port=80
service/svc-nginx exposed
[root@master ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP    4d
svc-nginx    ClusterIP   10.100.119.43   <none>        8000/TCP   3s
[root@master ~]# curl 10.100.119.43:8000
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

-示例：使用NodePort，集群外部可访问

[root@master ~]# kubectl expose pod nginx --name svc-nginx --type=NodePort --port=8000 --target-port=80
service/svc-nginx exposed
[root@master ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP          4d
svc-nginx    NodePort    10.107.26.219   <none>        8000:30987/TCP   4s
### 是k8s集群IP(任意节点ip均可)+30987端口即可访问，其中20，21，22是k8s集群节点ip
### 在浏览器中输入http://192.168.211.20:30987/ http://192.168.211.21:30987/  http://192.168.211.22:30987/ 都可以访问到nginx首页

8 delete¶

功能：删除资源
flag：
- --all：删除某类所有资源
- -A：在所有命令空间查
- -l：匹配指定的标签
示例：删除指定标签的pod

[root@master ~]# kubectl get pod --show-labels
NAME    READY   STATUS    RESTARTS   AGE   LABELS
nginx   1/1     Running   0          69m   run=nginx
[root@master ~]# kubectl delete pod  -l run=nginx
pod "nginx" deleted

9 label¶

功能：给资源添加标签
语法：kubectl label [--overwrite] (-f FILENAME | TYPE NAME) KEY_1=VAL_1 ... KEY_N=VAL_N [--resource-version=version]
- --overwrite：如果标签名存在，就会更新。默认不更新。直接返回错误
示例：示例给pod加上标签

[root@master ~]# kubectl label pod nginx version=1.0
pod/nginx labeled
[root@master ~]# kubectl get pod --show-labels
NAME    READY   STATUS    RESTARTS   AGE     LABELS
nginx   1/1     Running   0          2m23s   run=nginx,version=1.0

示例：更新标签

[root@master ~]# kubectl label pod nginx version=2.0
error: 'version' already has a value (1.0), and --overwrite is false
[root@master ~]# kubectl label pod nginx --overwrite version=2.0
pod/nginx labeled
[root@master ~]# kubectl get pod --show-labels
NAME    READY   STATUS    RESTARTS   AGE     LABELS
nginx   1/1     Running   0          4m59s   run=nginx,version=2.0

10 annotate¶

title: label和annotate区别？
1. label是给Kubernetes用的，可以使用便签和标签选择器来关联资源；
2. annotate是给人用的，用于展示给用户，让用户获取额外信息，Kubernetes并不使用这段信息。
3. label有长度限制，而annotate没有长度限制

功能：给资源添加或更新注释信息,annotations也是键值对形式
语法：kubectl annotate [--overwrite] (-f FILENAME | TYPE NAME) KEY_1=VAL_1 ... KEY_N=VAL_N [--resource-version=version]
- --list：显示资源annotations列表
- --overwrite：如果annotation存在相同的key，直接覆盖
- --record：1.在资源注解中记录当前的 kubectl 命令；2.记录到版本更新历史中
示例

[root@master k8s-yaml]# kubectl annotate deploy/nginx --overwrite --record  description="my deploy nginx 1"
Flag --record has been deprecated, --record will be removed in the future
deployment.apps/nginx annotated
[root@master k8s-yaml]# kubectl annotate deploy/nginx --overwrite description="my deploy nginx 1"
Flag --record has been deprecated, --record will be removed in the future
deployment.apps/nginx annotated
[root@master k8s-yaml]# kubectl annotate --list deploy/nginx
kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"labels":{"app":"nginx"},"name":"nginx","namespace":"default"},"spec":{"replicas":3,"selector":{"matchLabels":{"app":"nginx"}},"strategy":{"rollingUpdate":{"maxSurge":1,"maxUnavailable":1},"type":"RollingUpdate"},"template":{"metadata":{"labels":{"app":"nginx"}},"spec":{"containers":[{"image":"nginx","name":"nginx"}]}}}}

kubernetes.io/change-cause=kubectl annotate deploy/nginx description=my deploy nginx 1 --overwrite=true --record=true
deployment.kubernetes.io/revision=1
description=my deploy nginx 1

11 cp¶

功能：将文件和目录复制到容器和从容器复制。
语法：`kubectl cp
- --container NAME或-c NAME：指定具体的容器，默认是Pod的第一个容器
示例：

## Copy /tmp/foo from a remote pod to /tmp/bar locally
kubectl cp <some-namespace>/<some-pod>:/tmp/foo /tmp/bar
## Copy /tmp/foo local file to /tmp/bar in a remote pod in namespace
kubectl cp /tmp/foo <some-namespace>/<some-pod>:/tmp/bar
## Copy /tmp/foo from a remote pod to /tmp/bar locally
kubectl cp <some-namespace>/<some-pod>:/tmp/foo /tmp/bar

12 logs打印pod的日志¶

logs 只用来打印pod的日志，所以不需要执行资源的类型

语法形式：kubectl logs [-f] [-p] (POD | TYPE/NAME) [-c CONTAINER]
- -c CONTAINER：指定具体的容器
- --follow或-f：指定是否应流式传输日志。
- --tail=num：最后几条日志
- --since=time：当前时间之前多少时间内的，比如5s, 2m, 3h。
- --since-time=time：从指定时间之后的，使用RFC3339时间格式
示例

[root@master k8s-yaml]# kubectl logs nginx-8f458dc5b-lb97c --tail=20 --since=1h
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf
10-listen-on-ipv6-by-default.sh: info: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
/docker-entrypoint.sh: Configuration complete; ready for start up
2022/07/30 12:30:57 [notice] 1#1: using the "epoll" event method
2022/07/30 12:30:57 [notice] 1#1: nginx/1.21.5
2022/07/30 12:30:57 [notice] 1#1: built by gcc 10.2.1 20210110 (Debian 10.2.1-6) 
2022/07/30 12:30:57 [notice] 1#1: OS: Linux 5.18.10-1.el7.elrepo.x86_64
2022/07/30 12:30:57 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576
2022/07/30 12:30:57 [notice] 1#1: start worker processes
2022/07/30 12:30:57 [notice] 1#1: start worker process 30
2022/07/30 12:30:57 [notice] 1#1: start worker process 31

13 explain¶

功能：列出资源支持的字段信息
语法：kubectl explain RESOURCE
- RESOURCE：可以指定某资源具体字段，格式为<type>.<fieldName>[.<fieldName>]
示例

[root@master ~]# kubectl explain pod.spec.containers.image
KIND:     Pod
VERSION:  v1

FIELD:    image <string>

DESCRIPTION:
     Container image name. More info:
     https://kubernetes.io/docs/concepts/containers/images This field is
     optional to allow higher level config management to default or override
     container images in workload controllers like Deployments and StatefulSets.

14 kubectl中flags参数¶

14.1 -n指定命名空间¶

-n 是 --namespace 的简写

示例

[root@master ~]# kubectl get pod -n default
NAME        READY   STATUS    RESTARTS        AGE
nginx-pod   1/1     Running   1 (3h54m ago)   4h6m

14.2 -o格式化输出¶

-o 是--output的简写

-o name：仅打印资源名称而不打印任何其他内容。
-o wide：以纯文本格式输出，包含所有附加信息。对于 Pod 包含节点名。
-o yaml：输出 YAML 格式的 API 对象。
-o json：输出 JSON 格式的 API 对象
示例

[root@master ~]# kubectl  get pod 
NAME        READY   STATUS    RESTARTS       AGE
nginx-pod   1/1     Running   1 (143m ago)   155m
[root@master ~]# kubectl  get pod -o name
pod/nginx-pod
[root@master ~]# kubectl  get pod -o wide
NAME        READY   STATUS    RESTARTS       AGE    IP             NODE    NOMINATED NODE   READINESS GATES
nginx-pod   1/1     Running   1 (140m ago)   152m   10.244.104.2   node2   <none>           <none>

14.3 -w监听资源变化¶

-w 是 --watch 的简写

示例

[root@master ~]# kubectl get pod --watch 
NAME        READY   STATUS    RESTARTS       AGE
nginx-pod   1/1     Running   1 (160m ago)   172m

2. 更新命令¶

1 scale¶

功能：扩缩容。为deployment, replica set, replication controller,stateful set资源指定大小，增加或减少副本数
语法：kubectl scale [--resource-version=version] [--current-replicas=count] --replicas=COUNT (-f FILENAME | TYPE NAME)
- TYPE NAM：指定资源类型和名称
- --replicas=COUNT：期望的副本数
- --current-replicas=count：当前副本数（必须匹配当前副本数，才能执行，否则不执行）
- --selector或-l：资源需要匹配标签（ '=', '==', and '!='.(e.g. -l key1=value1,key2=value2).）
示例

[root@master k8s-yaml]# kubectl get deployments
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   3/3     3            3           75m
[root@master k8s-yaml]# kubectl scale  deployment/nginx  --current-replicas=3 --replicas=5
deployment.apps/nginx scaled
[root@master k8s-yaml]# kubectl get deployments
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   5/5     5            5           77m

2 edit¶

1. 默认编辑器是vi。可以通过修改环境变量KUBE_EDITOR或EDITOR来改变使用的文本编辑器
2. 可以yaml编辑文件，也可以直接编辑资源
3. 编辑时默认时以yaml格式显示资源配置，可以使用`-o json`参数指定json格式显示

功能：使用编辑器（linux默认vi）编辑资源，并重新上线
语法：kubectl edit (RESOURCE/NAME | -f FILENAME)
- --save-config：当前对象的配置将保存在其注解中
- --record：在资源注解中记录当前的 kubectl 命令
示例

## edit修改副本数由1->2
[root@master ~]# kubectl edit deployments/nginx --record
Flag --record has been deprecated, --record will be removed in the future
deployment.apps/nginx edited

## 查看版本历史
[root@master ~]# kubectl rollout history deploy/nginx
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
1         <none>
2         kubectl edit deployments/nginx --record=true

## 查看deploy信息
[root@master ~]# kubectl get deployments
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   1/2     2            1           25h

3 set¶

功能：配置应用程序资源
语法：kubectl set SUBCOMMAND

3.1 env¶

功能：更新pod模板上的环境变量
语法：kubectl set env RESOURCE/NAME KEY_1=VAL_1 ... KEY_N=VAL_N
- RESOURCE：支持的资源有pod (po), replicationcontroller (rc), deployment (deploy), daemonset (ds), statefulset (sts), cronjob (cj), replicaset (rs)
- --containers=NAME或-c NAME：指定具体的容器
- --overwrite：重写环境变量（如果环境变量已经存在，则覆盖）
- --list：显示环境变量列表
- --all：选择资源类型下所有资源
- --record：记录变更时命令，kubectl rollout history命令中能看到变更记录
示例1

[root@master ~]# kubectl set env deploy/nginx env1="hello world"
deployment.apps/nginx env updated
## 等待pod更新后，进入pod查看
[root@master ~]# kubectl exec nginx-86956484b-fgqsr -it -- /bin/bash
root@nginx-86956484b-fgqsr:/# echo $env1
hello world

示例2：显示环境变量列表

[root@master ~]# kubectl set env deploy --all --list
# Deployment nginx, container nginx
env1=hello world
[root@master ~]# kubectl set env pods --all --list
# Pod nginx-6b69b7d8fd-4vjps, container nginx
env1=hello world

3.2 image¶

功能：更新资源的现有容器镜像
语法：kubectl set image (-f FILENAME | TYPE NAME) CONTAINER_NAME_1=CONTAINER_IMAGE_1 ... CONTAINER_NAME_N=CONTAINER_IMAGE_N
- --record：记录变更时命令，kubectl rollout history命令中能看到变更记录
示例

[root@master ~]# kubectl set image deployment/nginx nginx=nginx:1.23  --record
Flag --record has been deprecated, --record will be removed in the future
deployment.apps/nginx image updated
[root@master ~]# kubectl describe deployments/nginx|grep Image
    Image:      nginx:1.23

3.3 resources¶

功能：为定义 pod 模板的任何资源指定计算资源要求（CPU、内存）
语法：kubectl set resources (-f FILENAME | TYPE NAME) ([--limits=LIMITS & --requests=REQUESTS]
- --limits=''：所能请求的计算机资源最大值，比如--limits=cpu=100m,memory=256Mi
- --requests=''：请求的资源（会收到limits的限制）
- -c, --containers='*'：指定具体的容器
- --record：记录变更时命令，kubectl rollout history命令中能看到变更记录
示例

[root@master ~]# kubectl set resources deployment nginx -c=nginx --limits=cpu=200m,memory=512Mi
deployment.apps/nginx resource requirements updated
[root@master ~]# kubectl describe deployments/nginx|grep -A 2 Limits
    Limits:
      cpu:     200m
      memory:  512Mi

4 rollout¶

功能：管理资源的上线服务
适用资源：
- deployments
- daemonsets
- statefulsets

4.1 history¶

更新资源时指定了 --record 选项，CHANGE-CAUSE字就会显示更新时执行的命令，否则显示<none>,示例：
- `kubectl set image deployment/nginx nginx=nginx:1.23 --record=true`

功能：查看以前的推出修订和配置。
语法：kubectl rollout history (TYPE NAME | TYPE/NAME) [flags]
示例

[root@master ~]# kubectl rollout history deployment nginx
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
1         <none>
2         <none>
[root@master ~]# kubectl set image deployment/nginx nginx=nginx:1.23  --record
Flag --record has been deprecated, --record will be removed in the future
deployment.apps/nginx image updated
[root@master ~]# kubectl rollout history deployment/nginx
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
1         <none>
2         <none>
3         kubectl set image deployment/nginx nginx=nginx:1.23 --record=true

4.2 pause¶

当前只支持deployment资源

功能：暂停资源的上线（此状态下，资源更新了，如deploy改变镜像版本，资源不会更新，直到恢复）
语法：kubectl rollout pause RESOURCE
示例

[root@master ~]# kubectl rollout pause deployment nginx
deployment.apps/nginx paused

4.3 restart¶

功能：重启资源（重新上线）
语法：kubectl restart pause RESOURCE
示例

[root@master ~]# kubectl rollout restart deployment nginx
deployment.apps/nginx restarted

### deploy资源重启中
[root@master ~]# kubectl get deployments
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   2/3     3            2           19h

4.4 resume¶

当前只支持deployment资源

功能：恢复暂停的资源（上线功能恢复）
语法：kubectl rollout resume RESOURCE
示例

[root@master ~]# kubectl rollout resume deployment nginx
deployment.apps/nginx resumed

4.5 status¶

功能：显示上线的状态
语法：kubectl rollout status RESOURCE
示例

[root@master ~]# kubectl set env deploy/nginx env1="hello world"
deployment.apps/nginx env updated
## 立即查看，上线过程中，实时更新状态，直到上线完成
[root@master ~]# kubectl rollout status deployment nginx
Waiting for deployment "nginx" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "nginx" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "nginx" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "nginx" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "nginx" rollout to finish: 2 of 3 updated replicas are available...
deployment "nginx" successfully rolled out

4.6 undo¶

功能：回滚版本
语法：kubectl rollout undo (TYPE NAME | TYPE/NAME) [flags]
- to-revision=num：回退到指定版本，默认回退到上一个版本
示例

[root@master ~]# kubectl rollout history deployment nginx
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
1         <none>
2         <none>
3         <none>

[root@master ~]# kubectl rollout undo deployment nginx --to-revision=2
deployment.apps/nginx rolled back
[root@master ~]# kubectl rollout history deployment nginx
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
1         <none>
3         <none>
4         <none>

### 版本2定义了env环境变量是"hello world"，结果显示正确
[root@master ~]# kubectl exec nginx-86956484b-kn8rz -it -- /bin/bash
root@nginx-86956484b-kn8rz:/# echo $env1 
hello world

3. 集群系统¶

1 version¶

功能：显示Kubernetes集群版本信息
语法：kubectl version
- --short：只显示版本号
- --client：只显示client版本信息
- -o [json/yaml]：输出格式
示例

[root@master ~]# kubectl version --short
Flag --short has been deprecated, and will be removed in the future. The --short output will become the default.
Client Version: v1.24.2
Kustomize Version: v4.5.4
Server Version: v1.24.2

2 api-resources¶

功能：显示支持的api资源
语法：kubectl api-resources
- --sort-by=[kind/name]：以kind或者name字段排序
- -o [wide/name]：wide显示详细信息，name只显示name字段
- --namespaced=bool：false显示非命名空间资源；true或者空显示命名空间资源
示例

[root@master ~]# kubectl api-resources --namespaced --sort-by=name
NAME                        SHORTNAMES   APIVERSION                     NAMESPACED   KIND
bindings                                 v1                             true         Binding
configmaps                  cm           v1                             true         ConfigMap
controllerrevisions                      apps/v1                        true         

....中间省略....

services                    svc          v1                             true         Service
statefulsets                sts          apps/v1                        true         StatefulSet

3 alpha¶

1. 此命令表示还属于alpha阶段，默认的Kubernetes集群时没有此功能。
2. 目前只支持events命令

3.1 events¶

功能：显示事件
语法：kubectl alpha events [--for TYPE/NAME] [--watch]
- --for TYPE/NAME：指定具体的资源
- --watch：监听事件
示例

[root@master ~]# kubectl alpha events --for pod/nginx
LAST SEEN           TYPE      REASON                 OBJECT      MESSAGE
50m (x2 over 51m)   Normal    TaintManagerEviction   Pod/nginx   Cancelling deletion of Pod default/nginx

4. 资源类型缩写统计¶

pod->po
nodes->no
namespaces->ns
persistentvolumeclaims ->pvc
persistentvolumes->pv
configmaps->cm
services->svc
deployment->deploy
daemonsets->ds
replicasets->rs
replicationcontrollers->rc
statefulsets->sts
storageclasses->sc

5. K8S快速生成yaml文件¶

第一种，使用kubectl create 命令生成:kubectl create deployment web --image=nginx -o yaml --dry-run > my1.yaml
第二种，使用kubectl get命令导出:kubectl get deploy nginx -o=yaml --export > my2.yaml