03-1-Kubectl
1. 查看相关信息
1.1. get
1.1.1. 基本信息查看
Usage: kubectl get resource [-o wide|json|yaml] [-n namespace]Man: 获取资源的相关信息，-n 指定名称空间，-o 指定输出格式resource可以是具体资源名称，如pod nginx-xxx；也可以是资源类型，如pod；或者all(仅展示几种核心资源，并不完整)-A, --all-namespace 表示显示所有名称空间
[root@hdss7-21 ~]# kubectl get cs
NAME STATUS MESSAGE ERROR
controller-manager Healthy ok
scheduler Healthy ok
etcd-1 Healthy {"health": "true"}
etcd-2 Healthy {"health": "true"}
etcd-0 Healthy {"health": "true"}
[root@hdss7-21 ~]# kubectl get node -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
hdss7-21.host.com Ready master,node 11d v1.15.2 10.4.7.21 <none> CentOS Linux 7 (Core) 3.10.0-862.el7.x86_64 docker://19.3.5
hdss7-22.host.com Ready master,node 11d v1.15.2 10.4.7.22 <none> CentOS Linux 7 (Core) 3.10.0-862.el7.x86_64 docker://19.3.5
[root@hdss7-21 ~]# kubectl get svc -o wide -n kube-system
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
coredns ClusterIP 192.168.0.2 <none> 53/UDP,53/TCP,9153/TCP 4d20h k8s-app=coredns
kubernetes-dashboard ClusterIP 192.168.140.139 <none> 443/TCP 3d9h k8s-app=kubernetes-dashboard
traefik-ingress-service ClusterIP 192.168.45.46 <none> 80/TCP,8080/TCP 3d19h k8s-app=traefik-ingress
[root@hdss7-21 ~]# kubectl get pod nginx-ds-jdp7q -o yaml
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: "2020-01-13T13:13:02Z"
generateName: nginx-ds-
labels:
app: nginx-ds
......
[root@centos-7-51 ~]# kubectl get pod -A
NAMESPACE NAME READY STATUS RESTARTS AGE
default pod-demo 1/1 Running 0 23m
kube-system coredns-7cf6c46dd5-9phnm 1/1 Running 2 6d1h
kube-system coredns-7cf6c46dd5-dm55x 1/1 Running 2 6d1h
kube-system etcd-centos-7-51 1/1 Running 2 6d1h
kube-system etcd-centos-7-52 1/1 Running 2 6d1h
kube-system etcd-centos-7-53 1/1 Running 2 6d1h
kube-system kube-apiserver-centos-7-51 1/1 Running 2 6d1h
kube-system kube-apiserver-centos-7-52 1/1 Running 2 6d1h
kube-system kube-apiserver-centos-7-53 1/1 Running 2 6d1h
kube-system kube-controller-manager-centos-7-51 1/1 Running 3 6d1h
kube-system kube-controller-manager-centos-7-52 1/1 Running 3 6d1h
kube-system kube-controller-manager-centos-7-53 1/1 Running 3 6d1h
kube-system kube-flannel-ds-c2bs6 1/1 Running 4 7d12h
kube-system kube-flannel-ds-t6j77 1/1 Running 5 7d12h
kube-system kube-flannel-ds-w526w 1/1 Running 4 7d12h
kube-system kube-flannel-ds-wp546 1/1 Running 5 7d12h
kube-system kube-flannel-ds-xc5cb 1/1 Running 3 7d12h
kube-system kube-proxy-b2dcj 1/1 Running 4 6d1h
kube-system kube-proxy-gjhjc 1/1 Running 4 6d1h
kube-system kube-proxy-m6xn7 1/1 Running 4 6d1h
kube-system kube-proxy-qpndv 1/1 Running 4 6d1h
kube-system kube-proxy-tbjz8 1/1 Running 4 6d1h
kube-system kube-scheduler-centos-7-51 1/1 Running 3 6d1h
kube-system kube-scheduler-centos-7-52 1/1 Running 3 6d1h
kube-system kube-scheduler-centos-7-53 1/1 Running 2 6d1h
kube-system metrics-server-c66c59557-vbhq4 1/1 Running 2 6d
kube-system traefik-ingress-controller-2gpfs 1/1 Running 3 7d11h
kube-system traefik-ingress-controller-8jhgb 1/1 Running 3 7d11h
kubernetes-dashboard dashboard-metrics-scraper-894c58c65-58ftb 1/1 Running 2 6d20h
kubernetes-dashboard kubernetes-dashboard-ffb9ffc86-2np2t 1/1 Running 2 6d17h
storage nfs-client-provisioner-5bdc64dd59-ss8cm 1/1 Running 3 6d
1.1.2. 根据标签筛选
--show-labels 显示所有标签
-l app 仅显示标签为app的资源
-l app=nginx 仅显示包含app标签，且值为nginx的资源
[root@hdss7-21 ~]# kubectl get pod -n app --show-labels
NAME READY STATUS RESTARTS AGE LABELS
pod-02 1/1 Running 0 9h app=nginx,release=stable,version=v1.12
pod-demo 1/1 Running 9 9h app=centos7,environment=dev,release=stable
[root@hdss7-21 ~]# kubectl get pod -n app --show-labels -l app
NAME READY STATUS RESTARTS AGE LABELS
pod-02 1/1 Running 0 9h app=nginx,release=stable,version=v1.12
pod-demo 1/1 Running 9 9h app=centos7,environment=dev,release=stable
[root@hdss7-21 ~]# kubectl get pod -n app --show-labels -l app=nginx
NAME READY STATUS RESTARTS AGE LABELS
pod-02 1/1 Running 0 9h app=nginx,release=stable,version=v1.12
1.2. describe
Usage: kubectl describe (-f FILENAME | TYPE [NAME_PREFIX | -l label] | TYPE/NAME) [-n namespace]
Man: 描述某个资源信息
[root@hdss7-21 ~]# kubectl describe svc nginx-web
Name: nginx-web
......
[root@hdss7-21 ~]# kubectl describe pod -l app=nginx-web
Name: nginx-web-796c86d7cd-8kst5
Namespace: default
......
1.3. 其它集群信息
[root@hdss7-21 ~]# kubectl version # 集群版本
Client Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.2", GitCommit:"f6278300bebbb750328ac16ee6dd3aa7d3549568", GitTreeState:"clean", BuildDate:"2019-08-05T09:23:26Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.2", GitCommit:"f6278300bebbb750328ac16ee6dd3aa7d3549568", GitTreeState:"clean", BuildDate:"2019-08-05T09:15:22Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"}
[root@hdss7-21 ~]# kubectl cluster-info # 集群信息
Kubernetes master is running at http://localhost:8080
CoreDNS is running at http://localhost:8080/api/v1/namespaces/kube-system/services/coredns:dns/proxy
kubernetes-dashboard is running at http://localhost:8080/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'
2. 创建资源
2.1. run(弃用)
Usage: kubectl run NAME --image=image [--env="key=value"] [--port=port] [--replicas=replicas] [--dry-run=bool] [options]
Man: 通过kubectl创建一个deployment或者Job。name为deployment的名字，image为容器的镜像
port为对容器外暴露的端口，replicas为副本数，dry-run为干运行(不创建pod)
[root@hdss7-21 ~]# kubectl run web-deploy --image=harbor.od.com/public/nginx:latest --replicas=2
[root@hdss7-21 ~]# kubectl get deployment
NAME READY UP-TO-DATE AVAILABLE AGE
web-deploy 2/2 2 2 92s
[root@hdss7-21 ~]# kubectl get pods|grep web-deploy
web-deploy-bc78f6667-5s6rq 1/1 Running 0 119s
web-deploy-bc78f6667-h67zb 1/1 Running 0 119s
2.2. create
Uage: kubectl create -f filename.yaml
kubectl create resourece [options]
Man: 根据清单文件或者指定的资源参数创建资源
[root@hdss7-21 ~]# kubectl create namespace app # 创建名称空间
[root@hdss7-21 ~]# kubectl get ns app
NAME STATUS AGE
app Active 10s
[root@hdss7-21 ~]# kubectl create deployment app-deploy --image=harbor.od.com/public/nginx:latest -n app # 创建deployment
[root@hdss7-21 ~]# kubectl get all -n app
NAME READY STATUS RESTARTS AGE
pod/app-deploy-5b5649fc4-plbxg 1/1 Running 0 13s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/app-deploy 1/1 1 1 13s
NAME DESIRED CURRENT READY AGE
replicaset.apps/app-deploy-5b5649fc4 1 1 1 13s
2.3. 创建service资源
Usage: Usage: kubectl expose TYPE NAME [--port=port] [--protocol=TCP|UDP|SCTP] [--target-port=n] [--name=name] [--external-ip=external-ip-of-service] [options]
Man: TYPE为deployment,NAME为depoly资源名称，port和target-port分别为集群和pod的端口
[root@hdss7-21 ~]# kubectl expose deployment app-deploy --port=80 --target-port=80 --name=app-svc -n app
[root@hdss7-21 ~]# kubectl describe svc app-svc -n app
Name: app-svc
Namespace: app
Labels: app=app-deploy
Annotations: <none>
Selector: app=app-deploy
Type: ClusterIP
IP: 192.168.28.124
Port: <unset> 80/TCP
TargetPort: 80/TCP
Endpoints: 172.7.21.8:80
3. 扩缩容
Usage: kubectl scale --replicas=COUNT TYPE NAME [options]
Man: 对资源进行扩缩容，即修改副本数
[root@hdss7-21 ~]# kubectl get deploy web-deploy
NAME READY UP-TO-DATE AVAILABLE AGE
web-deploy 2/2 2 2 37m
[root@hdss7-21 ~]# kubectl scale --replicas=5 deployment web-deploy # 扩容
[root@hdss7-21 ~]# kubectl get deploy web-deploy
NAME READY UP-TO-DATE AVAILABLE AGE
web-deploy 3/5 5 3 38m
[root@hdss7-21 ~]# kubectl scale --replicas=1 deployment web-deploy # 缩容
[root@hdss7-21 ~]# kubectl get deploy web-deploy
NAME READY UP-TO-DATE AVAILABLE AGE
web-deploy 1/1 1 1 38m
4. 删除资源
Usage: kubectl delete ([-f FILENAME] | [-k DIRECTORY] | TYPE [(NAME | -l label | --all)]) [options]
Man: 删除指定资源
[root@hdss7-21 ~]# kubectl get deployment -n app
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/app-deploy 1/1 1 1 35m
[root@hdss7-21 ~]# kubectl delete deployment app-deploy -n app
deployment.extensions "app-deploy" deleted
[root@hdss7-21 ~]# kubectl delete ns app
namespace "app" deleted
5. 贴附到pod上
Usage: kubectl exec (POD | TYPE/NAME) [-c CONTAINER] [flags] -- COMMAND [args...] [options]
[root@hdss7-21 ~]# kubectl exec nginx-web-796c86d7cd-zx2b9 -it -- /bin/bash # 交互式
root@nginx-web-796c86d7cd-zx2b9:/# exit
exit
[root@hdss7-21 ~]# kubectl exec nginx-web-796c86d7cd-zx2b9 -- cat /etc/resolv.conf
nameserver 192.168.0.2
search default.svc.cluster.local svc.cluster.local cluster.local host.com
options ndots:5
[root@hdss7-21 ~]# kubectl exec nginx-web-796c86d7cd-zx2b9 cat /etc/resolv.conf
nameserver 192.168.0.2
search default.svc.cluster.local svc.cluster.local cluster.local host.com
options ndots:5
6. 查看资源清单文档
[root@hdss7-21 ~]# kubectl api-versions # 查看api-version信息
apps/v1
node.k8s.io/v1beta1
v1
......
Usage: kubectl explain RESOURCE [options]
Man: 查看各个字段的解释，随着k8s版本的更新，不同资源的Apiversion会发生变化，当出现API错误时，需要查询当前的API版本
[root@hdss7-21 ~]# kubectl explain pod.spec.containers
KIND: Pod
VERSION: v1
RESOURCE: containers <[]Object>
7. 调度
污点：https://www.yuque.com/duduniao/k8s/hlzt2y#5IXMC
驱逐：https://www.yuque.com/duduniao/k8s/hlzt2y#H6ofT
8. Kubectl 命令补全
https://kubernetes.io/zh/docs/tasks/tools/install-kubectl/#启用-shell-自动补全功能
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