1. kubectl命令介绍

kubectl的命令语法

其中command，TYPE，NAME，和flags分别是：

: 指定要在一个或多个资源进行操作，例如create，get，describe，delete。
TYPE：指定。资源类型区分大小写，您可以指定单数，复数或缩写形式。例如，以下命令产生相同的输出：
```
kubectl get pod pod1  
kubectl get pods pod1 
kubectl get po pod1
```

NAME：指定资源的名称。名称区分大小写。如果省略名称，则会显示所有资源的详细信息,比如$ kubectl get pods。

按类型和名称指定多种资源：

* 要分组资源，如果它们都是相同的类型：`TYPE1 name1 name2 name<#>`.<br/>
例: `$ kubectl get pod example-pod1 example-pod2`
* 要分别指定多种资源类型:  `TYPE1/name1 TYPE1/name2 TYPE2/name3 TYPE<#>/name<#>`.<br/>
例: `$ kubectl get pod/example-pod1 replicationcontroller/example-rc1`

flags：指定可选标志。例如，您可以使用-s或--serverflags来指定Kubernetes API服务器的地址和端口。

更多命令介绍：

[root@node5 ~]# kubectl
kubectl controls the Kubernetes cluster manager.
Find more information at https://github.com/kubernetes/kubernetes.
Basic Commands (Beginner):
  create         Create a resource from a file or from stdin.
  expose         Take a replication controller, service, deployment or pod and expose it as a new Kubernetes Service
  run            Run a particular image on the cluster
  set            Set specific features on objects
  run-container  Run a particular image on the cluster. This command is deprecated, use "run" instead
  get            Display one or many resources
  edit           Edit a resource on the server
  delete         Delete resources by filenames, stdin, resources and names, or by resources and label selector
Deploy Commands:
  rollout        Manage the rollout of a resource
  rolling-update Perform a rolling update of the given ReplicationController
  scale          Set a new size for a Deployment, ReplicaSet, Replication Controller, or Job
  autoscale      Auto-scale a Deployment, ReplicaSet, or ReplicationController
Cluster Management Commands:
  certificate    Modify certificate resources.
  cluster-info   Display cluster info
  top            Display Resource (CPU/Memory/Storage) usage.
  cordon         Mark node as unschedulable
  uncordon       Mark node as schedulable
  drain          Drain node in preparation for maintenance
  taint          Update the taints on one or more nodes
Troubleshooting and Debugging Commands:
  describe       Show details of a specific resource or group of resources
  logs           Print the logs for a container in a pod
  attach         Attach to a running container
  exec           Execute a command in a container
  port-forward   Forward one or more local ports to a pod
  proxy          Run a proxy to the Kubernetes API server
  cp             Copy files and directories to and from containers.
  auth           Inspect authorization
Advanced Commands:
  apply          Apply a configuration to a resource by filename or stdin
  patch          Update field(s) of a resource using strategic merge patch
  replace        Replace a resource by filename or stdin
Settings Commands:
  annotate       Update the annotations on a resource
  completion     Output shell completion code for the specified shell (bash or zsh)
Other Commands:
  api-versions   Print the supported API versions on the server, in the form of "group/version"
  config         Modify kubeconfig files
  help           Help about any command
  plugin         Runs a command-line plugin
  version        Print the client and server version information
Use "kubectl <command> --help" for more information about a given command.
Use "kubectl options" for a list of global command-line options (applies to all commands).

2. 操作的常用资源对象

Node
Podes
Replication Controllers
Services
Namespace
Deployment
StatefulSet

具体对象类型及缩写：

3. kubectl命令分类[command]

1）create:[Create a resource by filename or stdin]

2）run:[ Run a particular image on the cluster]

4）proxy:[Run a proxy to the Kubernetes API server ]

3.2 删

1）delete:[Delete resources ]

1）scale:[Set a new size for a Replication Controller]

2）exec:[Execute a command in a container]

3）attach:[Attach to a running container]

4）patch:[Update field(s) of a resource by stdin]

5）edit:[Edit a resource on the server]

6） label:[Update the labels on a resource]

7）annotate:[Auto-scale a replication controller]

8）replace:[Replace a resource by filename or stdin]

9）config:[config modifies kubeconfig files]

3.4 查

2）describe:[Show details of a specific resource or group of resources]

3）log:[Print the logs for a container in a pod]

4）cluster-info:[Display cluster info]

5） version:[Print the client and server version information]

6）api-versions:[Print the supported API versions]

4. Pod相关命令

kubectl get pod -o wide --namespace=<NAMESPACE>

4.2 进入Pod

kubectl exec -it <PodName> /bin/bash --namespace=<NAMESPACE>
# 进入Pod中指定容器
kubectl exec -it <PodName> -c <ContainerName> /bin/bash --namespace=<NAMESPACE>

kubectl delete pod <PodName> --namespace=<NAMESPACE>
# 强制删除Pod，当Pod一直处于Terminating状态
kubectl delete pod <PodName> --namespace=<NAMESPACE> --force --grace-period=0

4.4 日志查看

5. Node隔离与恢复

说明：Node设置隔离之后，原先运行在该Node上的Pod不受影响，后续的Pod不会调度到被隔离的Node上。

1. Node隔离

# cordon命令
kubectl cordon <NodeName>
# 或者
kubectl patch node <NodeName> -p '{"spec":{"unschedulable":true}}'

2. Node恢复

# uncordon
kubectl uncordon <NodeName>
# 或者
kubectl patch node <NodeName> -p '{"spec":{"unschedulable":false}}'

6. kubectl label

1. 固定Pod到指定机器

2. 取消Pod固定机器

参考文章：

kubectl命令说明