这期内容当中小编将会给大家带来有关如何理解K8S中kubectl,文章内容丰富且以专业的角度为大家分析和叙述,阅读完这篇文章希望大家可以有所收获。
kubectl小洁: kubectl是官方的CLI命令行工具,用于apiserver进行通信,将用户在命令行输入的命令,组织并转化为apiserver能识别的信息,进而实现管理k8s各种资源的一种有效途径。 1、查看当前集群所有命名空间 [root@test-nodes1 ~]# kubectl get namespace NAME STATUS AGE default Active 42h kube-node-lease Active 42h kube-public Active 42h kube-system Active 42h ------------------------------------------------------------------------------------------ 2、查看default命名空间下的所有资源 [root@test-nodes1 ~]# kubectl get all -n default NAME READY STATUS RESTARTS AGE pod/nginx-ds-76fr8 0/1 ImagePullBackOff 0 39h pod/nginx-ds-zz7jn 0/1 ErrImagePull 0 39h pod/nginx-ds1-qg45q 1/1 Running 0 39h pod/nginx-ds1-whnmv 1/1 Running 0 39h #pod资源 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes ClusterIP 192.168.0.1 <none> 443/TCP 42h #service资源 NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE daemonset.apps/nginx-ds 2 2 0 2 0 <none> 39h daemonset.apps/nginx-ds1 2 2 2 2 2 <none> 39h #pod控制器 ------------------------------------------------------------------------------------------ 3、创建与删除命名空间 [root@test-nodes1 ~]# kubectl create namespace test namespace/test created [root@test-nodes1 ~]# kubectl get namespace NAME STATUS AGE default Active 42h kube-node-lease Active 42h kube-public Active 42h kube-system Active 42h test Active 6s [root@test-nodes1 ~]# kubectl delete namespace test namespace "test" deleted ------------------------------------------------------------------------------------------ 4、创建deployment(pods控制器)资源 [root@test-nodes1 ~]# kubectl create deployment nignx-dp --image=test-harbor.cedarhd.com/public/nginx:v1.7.9 -n kube-public deployment.apps/nignx-dp created ------------------------------------------------------------------------------------------ 5、查看kube-public命名空间下的deployment资源控制器 [root@test-nodes1 ~]# kubectl get deployment -n kube-public NAME READY UP-TO-DATE AVAILABLE AGE nignx-test 0/1 1 0 70s ------------------------------------------------------------------------------------------ 6、查看kube-public命名空间下pods的运行情况 [root@test-nodes1 ~]# kubectl get deployment -n kube-public NAME READY UP-TO-DATE AVAILABLE AGE nignx-test 1/1 1 1 21s ------------------------------------------------------------------------------------------ 7、查看kube-public空间下的pods资源 [root@test-nodes1 ~]# kubectl get pods -n kube-public -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nignx-dp-7f6d4979bd-nnc57 0/1 ImagePullBackOff 0 13m 172.7.21.4 test-nodes1.cedarhd.com <none> <none> nignx-test-655d6fbcb5-r9t57 1/1 Running 0 4m1s 172.7.22.4 test-nodes2.cedarhd.com <none> <none> ------------------------------------------------------------------------------------------ 8、在test-nodes2.cedarhd.com节点上curl 172.7.22.4 nginx [root@test-nodes2 ~]# curl 172.7.22.4 <!DOCTYPE html> <html> <head> <title>Welcome to nginx!</title> <style> body { width: 35em; margin: 0 auto; font-family: Tahoma, Verdana, Arial, sans-serif; } </style> </head> <body> <h2>Welcome to nginx!</h2> <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> ------------------------------------------------------------------------------------------ 9、查看deployment下具体pods(nginx-test)详细信息 [root@test-nodes1 ~]# kubectl describe deployment nignx-test -n kube-public Name: nignx-test Namespace: kube-public CreationTimestamp: Mon, 03 Feb 2020 02:02:59 -0500 Labels: app=nignx-test Annotations: deployment.kubernetes.io/revision: 1 Selector: app=nignx-test Replicas: 1 desired | 1 updated | 1 total | 1 available | 0 unavailable StrategyType: RollingUpdate MinReadySeconds: 0 RollingUpdateStrategy: 25% max unavailable, 25% max surge Pod Template: Labels: app=nignx-test Containers: nginx: Image: test-harbor.cedarhd.com/public/nginx:v1.7.9 Port: <none> Host Port: <none> Environment: <none> Mounts: <none> Volumes: <none> Conditions: Type Status Reason ---- ------ ------ Available True MinimumReplicasAvailable Progressing True NewReplicaSetAvailable OldReplicaSets: <none> NewReplicaSet: nignx-test-655d6fbcb5 (1/1 replicas created) Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal ScalingReplicaSet 22m deployment-controller Scaled up replica set nignx-test-655d6fbcb5 to 1 ------------------------------------------------------------------------------------------ 10、进入nginx-test pod资源 [root@test-nodes1 ~]# kubectl get pods -n kube-public NAME READY STATUS RESTARTS AGE nignx-test-655d6fbcb5-r9t57 1/1 Running 0 24m [root@test-nodes1 ~]# kubectl exec -ti nignx-test-655d6fbcb5-r9t57 /bin/bash -n kube-public #与docker 操作方法一致 root@nignx-test-655d6fbcb5-r9t57:/# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever 12: eth0@if13: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP link/ether 02:42:ac:07:16:04 brd ff:ff:ff:ff:ff:ff inet 172.7.22.4/24 brd 172.7.22.255 scope global eth0 valid_lft forever preferred_lft forever ------------------------------------------------------------------------------------------ 11、删除pod资源(即重启) [root@test-nodes1 ~]# kubectl delete pod nignx-test-655d6fbcb5-r9t57 -n kube-public pod "nignx-test-655d6fbcb5-r9t57" deleted [root@test-nodes1 ~]# kubectl get pods -n kube-public -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nignx-dp-7f6d4979bd-nnc57 0/1 ImagePullBackOff 0 40m 172.7.21.4 test-nodes1.cedarhd.com <none> <none> nignx-test-655d6fbcb5-c42z8 1/1 Running 0 18s 172.7.21.5 test-nodes1.cedarhd.com <none> <none> ------------------------------------------------------------------------------------------ 12、删除deployment [root@test-nodes1 ~]# kubectl get deploy -n kube-public NAME READY UP-TO-DATE AVAILABLE AGE nignx-dp 0/1 1 0 53m nignx-test 1/1 1 1 36m [root@test-nodes1 ~]# kubectl delete deploy nignx-dp -n kube-public deployment.extensions "nignx-dp" deleted ------------------------------------------------------------------------------------------ 13、为nginx-dp pod资源创建service资源,保障pod的高可用,通过集群IP访问 [root@test-nodes1 ~]# kubectl get all -n kube-public NAME READY STATUS RESTARTS AGE pod/nginx-dp-5b9b697bcc-jtrlp 1/1 Running 0 17s NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/nginx-dp 1/1 1 1 17s NAME DESIRED CURRENT READY AGE replicaset.apps/nginx-dp-5b9b697bcc 1 1 1 17s [root@test-nodes1 ~]# kubectl get pods -n kube-public -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nginx-dp-5b9b697bcc-jtrlp 1/1 Running 0 3m19s 172.7.21.4 test-nodes1.cedarhd.com <none> <none> [root@test-nodes1 ~]# kubectl expose deployment nginx-dp --port=80 -n kube-public service/nginx-dp exposed [root@test-nodes1 ~]# kubectl get svc -n kube-public #查看service资源 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nginx-dp ClusterIP 192.168.224.56 <none> 80/TCP 12m [root@test-nodes1 ~]# kubectl get all -n kube-public NAME READY STATUS RESTARTS AGE pod/nginx-dp-5b9b697bcc-jtrlp 1/1 Running 0 5m21s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/nginx-dp ClusterIP 192.168.224.56 <none> 80/TCP 79s NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/nginx-dp 1/1 1 1 5m21s NAME DESIRED CURRENT READY AGE replicaset.apps/nginx-dp-5b9b697bcc 1 1 1 5m21s [root@test-nodes1 ~]# curl 192.168.224.56 <!DOCTYPE html> <html> <head> <title>Welcome to nginx!</title> <style> body { width: 35em; margin: 0 auto; font-family: Tahoma, Verdana, Arial, sans-serif; } </style> </head> <body> <h2>Welcome to nginx!</h2> <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> [root@test-nodes1 ~]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 192.168.0.1:443 nq -> 10.3.153.221:6443 Masq 1 0 0 -> 10.3.153.222:6443 Masq 1 0 0 TCP 192.168.224.56:80 nq -> 172.7.21.4:80 Masq 1 0 0
小结: 声明式资源管理方法依赖于—资源配置清单(yaml\json),偏于修改POD配置。
1、查看当前pod的资源配置清单 [root@test-nodes1 ~]# kubectl get pods -n kube-public NAME READY STATUS RESTARTS AGE nginx-dp-5b9b697bcc-jtrlp 1/1 Running 0 5h31m -nodes1.cedarhd.com <none> <none> [root@test-nodes1 ~]# kubectl get pods nginx-dp-5b9b697bcc-jtrlp -n kube-public -o yaml apiVersion: v1 kind: Pod #类型为pod metadata: creationTimestamp: "2020-02-03T07:50:11Z" generateName: nginx-dp-5b9b697bcc- labels: app: nginx-dp pod-template-hash: 5b9b697bcc name: nginx-dp-5b9b697bcc-jtrlp namespace: kube-public ownerReferences: - apiVersion: apps/v1 blockOwnerDeletion: true controller: true kind: ReplicaSet name: nginx-dp-5b9b697bcc uid: 30bbaf90-c97e-4167-9419-45a632e9b3ce resourceVersion: "222257" selfLink: /api/v1/namespaces/kube-public/pods/nginx-dp-5b9b697bcc-jtrlp uid: 59d63844-8ee7-4d7e-8536-d4e5de1ba903 spec: containers: - image: test-harbor.cedarhd.com/public/nginx:v1.7.9 imagePullPolicy: IfNotPresent name: nginx resources: {} terminationMessagePath: /dev/termination-log terminationMessagePolicy: File volumeMounts: - mountPath: /var/run/secrets/kubernetes.io/serviceaccount name: default-token-nt4w9 readOnly: true dnsPolicy: ClusterFirst enableServiceLinks: true nodeName: test-nodes1.cedarhd.com priority: 0 restartPolicy: Always schedulerName: default-scheduler securityContext: {} serviceAccount: default serviceAccountName: default terminationGracePeriodSeconds: 30 tolerations: - effect: NoExecute key: node.kubernetes.io/not-ready operator: Exists tolerationSeconds: 300 - effect: NoExecute key: node.kubernetes.io/unreachable operator: Exists tolerationSeconds: 300 volumes: - name: default-token-nt4w9 secret: defaultMode: 420 secretName: default-token-nt4w9 status: conditions: - lastProbeTime: null lastTransitionTime: "2020-02-03T07:50:11Z" status: "True" type: Initialized - lastProbeTime: null lastTransitionTime: "2020-02-03T07:50:14Z" status: "True" type: Ready - lastProbeTime: null lastTransitionTime: "2020-02-03T07:50:14Z" status: "True" type: ContainersReady - lastProbeTime: null lastTransitionTime: "2020-02-03T07:50:11Z" status: "True" type: PodScheduled containerStatuses: - containerID: docker://745d5ad3412e5bccf2fb27dacce57e76987e8f6881cdb3aec79912888ba37ad6 image: test-harbor.cedarhd.com/public/nginx:v1.7.9 imageID: docker-pullable://test-harbor.cedarhd.com/public/nginx@sha256:b1f5935eb2e9e2ae89c0b3e2e148c19068d91ca502e857052f14db230443e4c2 lastState: {} name: nginx ready: true restartCount: 0 state: running: startedAt: "2020-02-03T07:50:13Z" hostIP: 10.3.153.221 phase: Running podIP: 172.7.21.4 qosClass: BestEffort startTime: "2020-02-03T07:50:11Z" ------------------------------------------------------------------------------------------ 2、获取service资源的配置清单 [root@test-nodes1 ~]# kubectl get service -n kube-public NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nginx-dp ClusterIP 192.168.224.56 <none> 80/TCP 5h31m [root@test-nodes1 ~]# kubectl get service nginx-dp -o yaml -n kube-public apiVersion: v1 kind: Service #类型为service metadata: creationTimestamp: "2020-02-03T07:54:13Z" labels: app: nginx-dp name: nginx-dp namespace: kube-public resourceVersion: "222606" selfLink: /api/v1/namespaces/kube-public/services/nginx-dp uid: 1b2310b5-6016-4692-b632-5c43d6dc4de5 spec: clusterIP: 192.168.224.56 ports: - port: 80 protocol: TCP targetPort: 80 selector: app: nginx-dp sessionAffinity: None type: ClusterIP status: loadBalancer: {} ------------------------------------------------------------------------------------------ 3、explain查看字段帮助说明 kubectl explain service.metadata ------------------------------------------------------------------------------------------ 4、新建一个service的资源配置清单 [root@test-nodes1 ~]# vi nginx-ds-svc.yaml apiVersion: v1 kind: Service metadata: labels: app: nginx-ds name: nginx-ds namespace: kube-public spec: ports: - port: 80 protocol: TCP targetPort: 80 selector: app: nginx-ds sessionAffinity: None type: ClusterIP ------------------------------------------------------------------------------------------ 5、通过声明式资源配置清单创建一个service资源 [root@test-nodes1 ~]# kubectl create -f nginx-ds-svc.yaml service/nginx-ds created [root@test-nodes1 ~]# kubectl get service -n kube-public NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nginx-dp ClusterIP 192.168.224.56 <none> 80/TCP 5h39m nginx-ds ClusterIP 192.168.66.3 <none> 80/TCP 16s ------------------------------------------------------------------------------------------ 6、在线修改nginx-ds的 service 资源端口为81 [root@test-nodes1 ~]# kubectl get svc -n kube-public NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nginx-dp ClusterIP 192.168.224.56 <none> 80/TCP 5h49m nginx-ds ClusterIP 192.168.66.3 <none> 80/TCP 10m [root@test-nodes1 ~]# kubectl edit svc nginx-ds -n kube-public # Please edit the object below. Lines beginning with a '#' will be ignored, # and an empty file will abort the edit. If an error occurs while saving this file will be # reopened with the relevant failures. # apiVersion: v1 kind: Service metadata: creationTimestamp: "2020-02-03T13:23:41Z" labels: app: nginx-ds name: nginx-ds namespace: kube-public resourceVersion: "250724" selfLink: /api/v1/namespaces/kube-public/services/nginx-ds uid: 5840630d-e00d-4e98-91a1-2b65a1eb22f4 spec: clusterIP: 192.168.66.3 ports: - port: 81 #修改对外端口81 protocol: TCP targetPort: 80 selector: app: nginx-ds sessionAffinity: None type: ClusterIP status: loadBalancer: {} "/tmp/kubectl-edit-wp634.yaml" 27L, 684C written service/nginx-ds edited [root@test-nodes1 ~]# kubectl get svc -n kube-public NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nginx-dp ClusterIP 192.168.224.56 <none> 80/TCP 5h50m nginx-ds ClusterIP 192.168.66.3 <none> 81/TCP 10m ------------------------------------------------------------------------------------------ 7、删除一个service资源 [root@test-nodes1 ~]# kubectl delete svc nginx-ds -n kube-public service "nginx-ds" deleted
[root@test-nodes1 ~]# kubectl get all -n kube-public NAME READY STATUS RESTARTS AGE pod/nginx-dp-5b9b697bcc-jtrlp 1/1 Running 0 6h2m #pod资源,承载容器应用所在 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/nginx-dp ClusterIP 192.168.224.56 <none> 80/TCP 5h67m #service资源,Service是Kubernetes里最核心的资源对象之一,Service定义了一个服务的访问入口地址,前端的应用(Pod)通过这个入口地址访问其背后的一组由Pod副本组成的集群实力 NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/nginx-dp 1/1 1 1 6h2m #deployment资源,Deployment同样也是Kubernetes系统的一个核心概念, 主要职责和RC一样的都是保证Pod的数量和健康,可理解为pod控制器, 当我们删除pod时,会再启动,不是真正删除,如需删除该pod,必须删除 该控制器 NAME DESIRED CURRENT READY AGE replicaset.apps/nginx-dp-5b9b697bcc 1 1 1 6h2m
1、创建一个nginx pod [root@test-nodes1 ~]# vi nginx-pod.yaml apiVersion: v1 kind: Pod metadata: name: nginx labels: app: web spec: containers: - name: nginx image: test-harbor.cedarhd.com/public/nginx:v1.7.9 ports: - containerPort: 80 [root@test-nodes1 ~]# kubectl create -f nginx-pod.yaml #创建一个POD pod/nginx created [root@test-nodes1 ~]# kubectl get all NAME READY STATUS RESTARTS AGE pod/nginx 1/1 Running 0 10m #刚刚创建的POD pod/nginx-ds1-qg45q 1/1 Running 0 47h pod/nginx-ds1-whnmv 1/1 Running 0 47h NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes ClusterIP 192.168.0.1 <none> 443/TCP 2d2h NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE daemonset.apps/nginx-ds1 2 2 2 2 2 <none> 47h ------------------------------------------------------------------------------------------ 2、为该pod创建一个service [root@test-nodes1 ~]# kubectl expose pod nginx --port=80 -n default service/nginx exposed [root@test-nodes2 ~]# kubectl get all NAME READY STATUS RESTARTS AGE pod/nginx 1/1 Running 0 14m pod/nginx-ds1-qg45q 1/1 Running 0 47h pod/nginx-ds1-whnmv 1/1 Running 0 47h NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes ClusterIP 192.168.0.1 <none> 443/TCP 2d2h service/nginx ClusterIP 192.168.123.163 <none> 80/TCP 107s NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE daemonset.apps/nginx-ds1 2 2 2 2 2 <none> 47h [root@test-nodes2 ~]# curl 192.168.123.163 获取nginx页面 ------------------------------------------------------------------------------------------ 3、创建一个deployment [root@test-nodes2 ~]# kubectl create deployment nginx-test --image=test-harbor.cedarhd.com/public/nginx:v1.7.9 deployment.apps/nginx-test created [root@test-nodes2 ~]# kubectl get all NAME READY STATUS RESTARTS AGE pod/nginx 1/1 Running 0 27m pod/nginx-ds1-qg45q 1/1 Running 0 47h pod/nginx-ds1-whnmv 1/1 Running 0 47h pod/nginx-test-5674474869-5nr7j 1/1 Running 0 4s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes ClusterIP 192.168.0.1 <none> 443/TCP 2d2h service/nginx ClusterIP 192.168.123.163 <none> 80/TCP 15m NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE daemonset.apps/nginx-ds1 2 2 2 2 2 <none> 47h NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/nginx-test 1/1 1 1 4s NAME DESIRED CURRENT READY AGE replicaset.apps/nginx-test-5674474869 1 1 1 4s
上述就是小编为大家分享的如何理解K8S中kubectl了,如果刚好有类似的疑惑,不妨参照上述分析进行理解。如果想知道更多相关知识,欢迎关注亿速云行业资讯频道。
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