kubernetes 基础管理

kubernetes 基础管理

kubectl 命令

命令说明

命令格式命令说明kubectl run 资源名称 -参数 --image=镜像名称:标签创建资源对象，常用参数-i交互，-t终端kubectl get 查询资源 可选参数 -o wide 显示主机信息常用查询的资源 node|deployment|podkubectl exec -it 容器id 执行的命令同 docker exec 指令，进入容器内kubectl describe 资源类型 资源名称查询资源的详细信息kubectl attach同 docker attach 指令，连接容器kubectl logs 容器id查看容器控制台的标准输出kubectl delete 资源类型 资源名称删除指定的资源kubectl create|apply -f 资源文件执行指定的资源文件

命令案例

# 执行指定的资源文件 [root@master flannel]# kubectl apply -f kube-flannel.yml # get 查询信息 [root@master ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION master Ready master 19h v1.17.6 node-0001 Ready <none> 16h v1.17.6 [root@master ~]# kubectl -n kube-system get pod NAME READY STATUS RESTARTS AGE kube-flannel-ds-amd64-hf2jp 1/1 Running 0 41m kube-flannel-ds-amd64-rtl4l 1/1 Running 0 41m ... ... # describe 查询详细信息 [root@master ~]# kubectl -n kube-system describe pod kube-flannel-ds-amd64-rtl4l Name: kube-proxy-4tbp6 Namespace: kube-system ... ... # 使用run启动容器 [root@master ~]# kubectl run testos -it --image=192.168.1.100:5000/myos:v1804 [root@testos-79778b4895-s8mxl /]# # 启动服务 [root@master ~]# kubectl run web-test --image=192.168.1.100:5000/myos:httpd kubectl run --generator=deployment/apps.v1 is DEPRECATED and will be removed in a future version. Use kubectl run --generator=run-pod/v1 or kubectl create instead. deployment.apps/web-test created # 访问节点 [root@master ~]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP testos-79778b4895-s8mxl 1/1 Running 1 6m33s 10.244.3.2 ... ... web-test-7bf98b9576-v566c 1/1 Running 0 4m24s 10.244.4.2 ... ... [root@master ~]# curl http://10.244.4.2/info.php <pre> Array ( [REMOTE_ADDR] => 10.244.0.0 [REQUEST_METHOD] => GET [HTTP_USER_AGENT] => curl/7.29.0 [REQUEST_URI] => /info.php ) php_host: web-test-7bf98b9576-v566c 1229 # 进入容器 [root@master ~]# kubectl exec -it testos-79778b4895-s8mxl -- /bin/bash [root@testos-79778b4895-s8mxl /]# [root@master ~]# kubectl attach -it testos-79778b4895-s8mxl [root@testos-79778b4895-s8mxl /]# # 查看终端日志 [root@master ~]# kubectl logs web-test-7bf98b9576-v566c AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 10.244.4.2. Set the 'ServerName' directive globally to suppress this message # 删除资源，直接删除POD会自动重建 [root@master ~]# kubectl delete pod testos-79778b4895-s8mxl pod "testos-79778b4895-s8mxl" deleted [root@master ~]# kubectl delete deployments testos deployment.apps "testos" deleted

资源文件

在k8s集群中，latest标签是不会被缓存，如果想缓存可以使用其他标签

[root@master ~]# docker pull 192.168.1.100:5000/myos:latest [root@master ~]# docker tag 192.168.1.100:5000/myos:latest 192.168.1.100:5000/myos:v1804 [root@master ~]# docker push 192.168.1.100:5000/myos:v1804 [root@master ~]# curl http://192.168.1.100:5000/v2/myos/tags/list {"name":"myos","tags":["nginx","php-fpm","latest","v1804","httpd"]}

pod-example资源文件

[root@master config]# vim pod-example.yaml --- apiVersion: v1 kind: Pod metadata: name: pod-example labels: app: myos spec: containers: - name: myos image: 192.168.1.100:5000/myos:v1804 stdin: true tty: true restartPolicy: Always [root@master config]# kubectl apply -f pod-example.yaml pod/pod-example created [root@master config]# kubectl get pod NAME READY STATUS RESTARTS AGE pod-example 1/1 Running 0 6s [root@master config]# kubectl delete -f pod-example.yaml pod "pod-example" deleted

简单web集群案例

[root@master ~]# vim deployment-example.yaml --- apiVersion: apps/v1 kind: Deployment metadata: name: httpd spec: selector: matchLabels: app: myapp replicas: 3 template: metadata: labels: app: myapp spec: containers: - name: apache image: 192.168.1.100:5000/myos:httpd restartPolicy: Always [root@master ~]# kubectl apply -f deployment-example.yaml deployment.apps/httpd created [root@master ~]# kubectl get pod NAME READY STATUS RESTARTS AGE httpd-679f76478-8ltrw 1/1 Running 0 5s httpd-679f76478-rcp76 1/1 Running 0 5s httpd-679f76478-vwjvr 1/1 Running 0 5s

集群调度

扩容与缩减

[root@master ~]# kubectl get deployments.apps NAME READY UP-TO-DATE AVAILABLE AGE httpd 3/3 3 3 60m [root@master ~]# kubectl scale deployment httpd --replicas=2 deployment.apps/httpd scaled [root@master ~]# kubectl get deployments.apps NAME READY UP-TO-DATE AVAILABLE AGE httpd 2/2 2 2 61m

滚动更新集群

刚刚使用 deployment-example.yaml 创建的 apache，我们更新集群为 nginx

拷贝 deployment-example.yaml 进行编辑或使用云盘中的模板文件

[root@master ~]# vim http-example-v2.yaml --- apiVersion: apps/v1 kind: Deployment metadata: name: httpd spec: selector: matchLabels: app: myapp replicas: 3 revisionHistoryLimit: 10 strategy: rollingUpdate: maxSurge: 25% maxUnavailable: 25% type: RollingUpdate template: metadata: labels: app: myapp spec: containers: - name: apache image: 192.168.1.100:5000/myos:nginx restartPolicy: Always [root@master ~]# kubectl apply -f http-example-v2.yaml # 查看历史版本并回滚 [root@master ~]# kubectl get deployments NAME READY UP-TO-DATE AVAILABLE AGE httpd 3/3 3 3 78m [root@master ~]# kubectl rollout history deployment httpd deployment.apps/httpd REVISION CHANGE-CAUSE 1 <none> 2 <none> [root@master ~]# kubectl rollout undo deployment httpd --to-revision=1

daemonset控制器

[root@master ~]# cat daemonset-expmple.yaml --- apiVersion: apps/v1 kind: DaemonSet metadata: name: daemonset-example namespace: default spec: selector: matchLabels: app: myapp1 template: metadata: labels: app: myapp1 spec: containers: - name: myos image: 192.168.1.100:5000/myos:v1804 stdin: true tty: true restartPolicy: Always [root@master ~]# kubectl apply -f daemonset-expmple.yaml

污点标签

[root@master ~]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE httpd-679f76478-7x7rw 1/1 Running 0 72m 10.244.3.6 node-0003 httpd-679f76478-gk2rk 1/1 Running 0 72m 10.244.4.6 node-0002 httpd-679f76478-sqvvc 1/1 Running 0 72m 10.244.5.7 node-0001 [root@master ~]# kubectl taint node node-0003 k1=v1:NoExecute node/node-0003 tainted [root@master ~]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE httpd-679f76478-gk2rk 1/1 Running 0 73m 10.244.4.6 node-0002 httpd-679f76478-qbkst 1/1 Running 0 6s 10.244.4.8 node-0002 httpd-679f76478-sqvvc 1/1 Running 0 73m 10.244.5.7 node-0001 # 查看污点标签 [root@master ~]# kubectl describe nodes node-0003 |grep -P "^Taints:" Taints: k1=v1:NoExecute # 删除污点标签 [root@master ~]# kubectl taint node node-0003 k1-

节点选择器

[root@master ~]# vim http-example-v3.yaml --- apiVersion: apps/v1 kind: Deployment metadata: name: httpd spec: selector: matchLabels: app: myapp replicas: 1 template: metadata: labels: app: myapp spec: nodeSelector: disktype: ssd containers: - name: apache image: 192.168.1.100:5000/myos:httpd restartPolicy: Always [root@master ~]# kubectl apply -f http-example-v3.yaml deployment.apps/httpd created [root@master ~]# kubectl get pod NAME READY STATUS RESTARTS AGE httpd-6bffbcb9d8-hgqvv 0/1 Pending 0 39s [root@master ~]# kubectl label nodes node-0003 disktype=ssd node/node-0003 labeled [root@master ~]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE httpd-6bffbcb9d8-hgqvv 1/1 Running 0 2m8s 10.244.3.9 node-0003

job/cronjob控制器

[root@master config]# vim job-example.yaml --- apiVersion: batch/v1 kind: Job metadata: name: pi spec: template: spec: containers: - name: pi image: 192.168.1.100:5000/myos:v1804 command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(500)"] restartPolicy: OnFailure [root@master config]# kubectl apply -f job-example.yaml job.batch/pi created [root@master config]# kubectl get job NAME COMPLETIONS DURATION AGE pi 1/1 2s 7s [root@master config]# kubectl get pod NAME READY STATUS RESTARTS AGE httpd-6bffbcb9d8-hgqvv 1/1 Running 0 12m pi-gvfwj 0/1 Completed 0 15s # 查看终端结果 [root@master config]# kubectl logs pi-gvfwj [root@master ~]# vim cronjob-example.yaml --- apiVersion: batch/v1beta1 kind: CronJob metadata: name: cronjob-pi spec: schedule: "*/1 * * * *" jobTemplate: spec: template: spec: containers: - name: pi image: 192.168.1.100:5000/myos:v1804 command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(500)"] restartPolicy: OnFailure [root@master ~]# kubectl apply -f cronjob-example.yaml cronjob.batch/cronjob-pi created [root@master ~]# kubectl get cronjobs.batch NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE cronjob-pi */1 * * * * False 0 <none> 10s [root@master ~]# kubectl get pod NAME READY STATUS RESTARTS AGE cronjob-pi-1595410620-vvztx 0/1 Completed 0 62s