# K8s基本操作命令 ## 一、namespace操作 ### 1）列出集群中所有API组名/版本号： `kubectl api-versions` 输出： ``` admissionregistration.k8s.io/v1 admissionregistration.k8s.io/v1beta1 apiextensions.k8s.io/v1 apiextensions.k8s.io/v1beta1 apiregistration.k8s.io/v1 apiregistration.k8s.io/v1beta1 apps/v1 authentication.k8s.io/v1 authentication.k8s.io/v1beta1 authorization.k8s.io/v1 authorization.k8s.io/v1beta1 autoscaling/v1 autoscaling/v2beta1 autoscaling/v2beta2 batch/v1 batch/v1beta1 certificates.k8s.io/v1beta1 coordination.k8s.io/v1 coordination.k8s.io/v1beta1 discovery.k8s.io/v1beta1 events.k8s.io/v1beta1 extensions/v1beta1 networking.k8s.io/v1 networking.k8s.io/v1beta1 node.k8s.io/v1beta1 policy/v1beta1 rbac.authorization.k8s.io/v1 rbac.authorization.k8s.io/v1beta1 scheduling.k8s.io/v1 scheduling.k8s.io/v1beta1 storage.k8s.io/v1 storage.k8s.io/v1beta1 v1 ``` ### 2）列出集群名称空间： `kubectl get namespaces` 输出结果： ``` NAME STATUS AGE default Active 2d20h kube-node-lease Active 2d20h kube-public Active 2d20h kube-system Active 2d20h ``` ### 3）创建新的名称空间： `kubectl create namespace new-space-name` 以上`namespace`均可以简写成`ns`，如：`kubectl create ns new-space-name` ### 4）列出集群内所有名称空间下所有pod： `kubectl get pod --all-namespaces` ## 二、Pod操作 ### 1）根据配置清单创建pod： `kubectl apply -f new-pod.yaml` ### 2）删除pod： `kubectl delete pods pod-name` ### 3）查看pod： `kubectl get pods` ### 4）通过镜像文件直接创建pod和无状态应用： ``` kubectl create deployment test1 --image=maxidea/flask-demo-app:v1.0 ``` ### 5）查看一下对应的pod和无状态应用： ``` $ kubectl get pods NAME READY STATUS RESTARTS AGE test1-86d54d9655-q9lv5 1/1 Running 0 5m15s $ kubectl get deploy NAME READY UP-TO-DATE AVAILABLE AGE test1 1/1 1 1 5m30s ``` 访问这个服务，首先查看一下它的ip地址，可以看到它被部署到哪个节点上去（这里被部署到36工作节点上），使用命令格式： `kubectl get pods -o wide` ``` $ kubectl get pods -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES test1-86d54d9655-q9lv5 1/1 Running 0 7m40s 10.244.2.2 36 $ curl 10.244.2.2 flask-demo-app v1.0 / ClientIP: 10.244.0.0, ServerName: test1-86d54d9655-q9lv5, ServerIP: 10.244.2.2! ``` ### 6）查看pod的配置清单 ``` $ kubectl create deployment test2 --image=maxidea/flask-demo-app:v1.0 --dry-run=client -o yaml apiVersion: apps/v1 kind: Deployment metadata: creationTimestamp: null labels: app: test2 name: test2 spec: replicas: 1 selector: matchLabels: app: test2 strategy: {} template: metadata: creationTimestamp: null labels: app: test2 spec: containers: - image: maxidea/flask-demo-app:v1.0 name: flask-demo-app resources: {} status: {} ``` ### 7）查看pod的label `kubectl get pods --show-labels` ``` NAME READY STATUS RESTARTS AGE LABELS new-pod 1/1 Running 0 15h test1-86d54d9655-q9lv5 1/1 Running 0 18h app=test1,pod-template-hash=86d54d9655 test2-69444f54b-4phj2 1/1 Running 0 7m40s app=test2,pod-template-hash=69444f54b ``` ### 7）查看指定名称空间下pod的资源使用情况 `kubectl top pods -n [namespaces]` 例如： ``` [root@consumer-prd-paas-k8s-masterb-0 ~]# kubectl top pods -n momtest NAME CPU(cores) MEMORY(bytes) r-49b86 132m 249Mi r-569wf 177m 353Mi r-5g9jp 168m 284Mi r-6sp9t 164m 237Mi r-859fw 154m 263Mi r-8ggdz 183m 260Mi ``` 对指定pod资源状态自动刷新： `watch 'kubectl top pods -n momtest r-vqnc2'` ### 8）查看每个节点主机资源使用情况 `kubectl top node` ## 三、Service操作 ### 1）创建service `kubectl create service clusterip test1 --tcp=80` 这里要注意，如果需要pod自动关联这个service，service的名字需要和pod一致。 查看这个创建的service： ``` $ kubectl get service NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 443/TCP 3d4h test1 ClusterIP 10.102.176.227 80/TCP 18s ``` 查看service相关详细信息： ``` $ kubectl describe service test1 Name: test1 Namespace: default Labels: app=test1 Annotations: Selector: app=test1 Type: ClusterIP IP: 10.102.176.227 Port: 80 80/TCP TargetPort: 80/TCP Endpoints: 10.244.2.2:80 Session Affinity: None Events: ``` 这里看到pod test1已经作为这个service的Endpoints了。 从同一集群的其他pod（用`kubectl exec -it pod_name -- /bin/sh`进入）访问这个service，注意地址结构：`[service name].[namespace].svc.[cluster domain]`也可以使用这个service的ip地址访问：`10.102.176.227` ``` # curl test1.default.svc.cluster.local flask-demo-app v1.0 / ClientIP: 10.244.1.3, ServerName: test1-86d54d9655-q9lv5, ServerIP: 10.244.2.2! ``` ### 2）扩展/缩小service下的pod个数 例如，把test1的副本数量扩展/缩少到三个（用同一命令指定数量即可）： `kubectl scale deployment/test1 --replicas=3` ``` $ kubectl get pods -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES new-pod 1/1 Running 0 18h 10.244.1.3 35 test1-86d54d9655-c9h5m 1/1 Running 0 84s 10.244.1.4 35 test1-86d54d9655-htbkd 1/1 Running 0 84s 10.244.3.4 37 test1-86d54d9655-q9lv5 1/1 Running 0 21h 10.244.2.2 36 ``` 可以看到在三个工作节点上会自动生成另外两个一样的pod。 ``` flask-demo-app v1.0 / ClientIP: 10.244.1.3, ServerName: test1-86d54d9655-htbkd, ServerIP: 10.244.3.4! flask-demo-app v1.0 / ClientIP: 10.244.1.3, ServerName: test1-86d54d9655-q9lv5, ServerIP: 10.244.2.2! flask-demo-app v1.0 / ClientIP: 10.244.1.3, ServerName: test1-86d54d9655-c9h5m, ServerIP: 10.244.1.4! ``` ### 3）service的iptable规则 集群每创建一个新的pod，都会在节点宿主机的`iptables`上创建对应的新规则，例如： ``` # iptables -t nat -S KUBE-SERVICES | grep test1 -A KUBE-SERVICES ! -s 10.244.0.0/16 -d 10.102.176.227/32 -p tcp -m comment --comment "default/test1:80 cluster IP" -m tcp --dport 80 -j KUBE-MARK-MASQ -A KUBE-SERVICES -d 10.102.176.227/32 -p tcp -m comment --comment "default/test1:80 cluster IP" -m tcp --dport 80 -j KUBE-SVC-VRCN2UH6RARGOJZA # iptables -t nat -S KUBE-SVC-VRCN2UH6RARGOJZA -N KUBE-SVC-VRCN2UH6RARGOJZA -A KUBE-SVC-VRCN2UH6RARGOJZA -m comment --comment "default/test1:80" -m statistic --mode random --probability 0.33333333349 -j KUBE-SEP-M4LMZLRGTFEOZERX -A KUBE-SVC-VRCN2UH6RARGOJZA -m comment --comment "default/test1:80" -m statistic --mode random --probability 0.50000000000 -j KUBE-SEP-LL5YVFAV2NKPJ2W3 -A KUBE-SVC-VRCN2UH6RARGOJZA -m comment --comment "default/test1:80" -j KUBE-SEP-OSFWLWIVOCAZBH6N # iptables -t nat -S KUBE-SEP-M4LMZLRGTFEOZERX -N KUBE-SEP-M4LMZLRGTFEOZERX -A KUBE-SEP-M4LMZLRGTFEOZERX -s 10.244.1.4/32 -m comment --comment "default/test1:80" -j KUBE-MARK-MASQ -A KUBE-SEP-M4LMZLRGTFEOZERX -p tcp -m comment --comment "default/test1:80" -m tcp -j DNAT [unsupported revision] ``` 完整的iptables规则如下图： ![来源：https://github.com/cilium/k8s-iptables-diagram](/files/-M8-CHcWcJ0gfM8gdTdA) ### 4）service的ipvs规则 对于使用ipvs的集群，上述规则在ipvs下显示如下，对比iptables，ipvs更为简单和高效：（通过修改`kube-proxy`的`configMap`里的`mode`字段为`“ipvs”`来配置） 工作节点上安装`apt install ipvsadm` ``` # ipvsadm -L -n IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 10.96.0.1:443 rr -> 192.168.2.31:6443 Masq 1 0 0 -> 192.168.2.32:6443 Masq 1 0 0 -> 192.168.2.33:6443 Masq 1 0 0 TCP 10.96.0.10:53 rr -> 10.244.0.2:53 Masq 1 0 0 -> 10.244.0.3:53 Masq 1 0 0 TCP 10.96.0.10:9153 rr -> 10.244.0.2:9153 Masq 1 0 0 -> 10.244.0.3:9153 Masq 1 0 0 TCP 10.102.176.227:80 rr -> 10.244.1.4:80 Masq 1 0 0 -> 10.244.2.2:80 Masq 1 0 0 -> 10.244.3.4:80 Masq 1 0 0 UDP 10.96.0.10:53 rr -> 10.244.0.2:53 Masq 1 0 0 -> 10.244.0.3:53 Masq 1 0 0 ``` ## 四、ConfigMap操作 ### 1）列出configmap资源（kebu-system名称空间下） ``` $ kubectl get cm -n kube-system NAME DATA AGE coredns 1 3d23h extension-apiserver-authentication 6 3d23h kube-flannel-cfg 2 3d15h kube-proxy 2 3d23h kubeadm-config 2 3d23h kubelet-config-1.18 1 3d23h ``` ### 2）修改kube-proxy `kubectl edit cm kube-proxy -n kube-system` `-n kube-system`为指定名称空间。 修改完kube-proxy，需要删除并重新生成kube-system下的对应6个kube-proxy的pod（由于这里测试用的主节点+工作节点有6个）。 实现批量删除，通过labels： ``` $ kubectl get pods -n kube-system --show-labels NAME READY STATUS RESTARTS AGE LABELS coredns-7ff77c879f-7t8nw 1/1 Running 0 3d23h k8s-app=kube-dns,pod-template-hash=7ff77c879f coredns-7ff77c879f-bpkwh 1/1 Running 0 3d23h k8s-app=kube-dns,pod-template-hash=7ff77c879f etcd-31 1/1 Running 2 3d23h component=etcd,tier=control-plane etcd-32 1/1 Running 0 2d14h component=etcd,tier=control-plane etcd-33 1/1 Running 0 2d14h component=etcd,tier=control-plane kube-apiserver-31 1/1 Running 2 3d23h component=kube-apiserver,tier=control-plane kube-apiserver-32 1/1 Running 0 2d14h component=kube-apiserver,tier=control-plane kube-apiserver-33 1/1 Running 0 2d14h component=kube-apiserver,tier=control-plane kube-controller-manager-31 1/1 Running 3 3d23h component=kube-controller-manager,tier=control-plane kube-controller-manager-32 1/1 Running 1 2d14h component=kube-controller-manager,tier=control-plane kube-controller-manager-33 1/1 Running 0 2d14h component=kube-controller-manager,tier=control-plane kube-flannel-ds-amd64-76cdz 1/1 Running 0 3d15h app=flannel,controller-revision-hash=56c5465959,pod-template-generation=1,tier=node kube-flannel-ds-amd64-ct8v2 1/1 Running 0 2d17h app=flannel,controller-revision-hash=56c5465959,pod-template-generation=1,tier=node kube-flannel-ds-amd64-h6m9w 1/1 Running 0 2d17h app=flannel,controller-revision-hash=56c5465959,pod-template-generation=1,tier=node kube-flannel-ds-amd64-l6rfc 1/1 Running 0 2d14h app=flannel,controller-revision-hash=56c5465959,pod-template-generation=1,tier=node kube-flannel-ds-amd64-nm5rl 1/1 Running 0 2d17h app=flannel,controller-revision-hash=56c5465959,pod-template-generation=1,tier=node kube-flannel-ds-amd64-qlv78 1/1 Running 0 2d14h app=flannel,controller-revision-hash=56c5465959,pod-template-generation=1,tier=node kube-proxy-27226 1/1 Running 0 2d14h controller-revision-hash=55877fc8b6,k8s-app=kube-proxy,pod-template-generation=1 kube-proxy-5qmnq 1/1 Running 0 2d17h controller-revision-hash=55877fc8b6,k8s-app=kube-proxy,pod-template-generation=1 kube-proxy-79vk2 1/1 Running 0 2d17h controller-revision-hash=55877fc8b6,k8s-app=kube-proxy,pod-template-generation=1 kube-proxy-hwfss 1/1 Running 2 3d23h controller-revision-hash=55877fc8b6,k8s-app=kube-proxy,pod-template-generation=1 kube-proxy-ms2lx 1/1 Running 0 2d17h controller-revision-hash=55877fc8b6,k8s-app=kube-proxy,pod-template-generation=1 kube-proxy-z68st 1/1 Running 0 2d14h controller-revision-hash=55877fc8b6,k8s-app=kube-proxy,pod-template-generation=1 kube-scheduler-31 1/1 Running 4 3d23h component=kube-scheduler,tier=control-plane kube-scheduler-32 1/1 Running 0 2d14h component=kube-scheduler,tier=control-plane kube-scheduler-33 1/1 Running 1 2d14h component=kube-scheduler,tier=control-plane ``` 看到这6个pod都具有同一个label叫`k8s-app=kube-proxy,` 所以如2-2的操作，批量删除加入`label`后的指令是： `kubectl delete pods -l k8s-app=kube-proxy -n kube-system` kube-proxy的pod被删除后重新根据修改后的配置清单生成新的pod。 ## 五、deployments/rc/rs删除操作 上面测试用的两个pod，如果直接使用`kubectl delete pod`来删除，过一会又会生成新的pod，原因是对应的pod在创建时，kubernetes创建了对应的deployment和rs（副本集replicasets）来监控pod的生命周期。所以，要删除这两个pod，首先要删除对应的deployment/rc/rs。 检查是否创建了deployments任务：`kubectl get deployments` 检查是否创建了副本控制器ReplicationController：`kubectl get rc` 检查死否创建了副本集replicasets：`kubectl get rs` 删除对应的对应的deployment：`kubectl delete deployment test1` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://maxidea.gitbook.io/k8s-testing/kubernetes-ji-chu/k8s-ji-ben-cao-zuo-ming-ling.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.