2.K8S的核心资源管理方法
目录
1.1陈述式资源管理方法
1.1.1.管理名称空间资源
1.1.2.管理Deployment资源
1.1.3.管理Service资源
1.1.4.kubectl用法总结
1.2.声明式资源管理方法
1.1.1.管理名称空间资源
查看名称空间
[root@hdss7-21 ~]# kubectl get namespace NAME STATUS AGE default Active 4d19h kube-node-lease Active 4d19h kube-public Active 4d19h kube-system Active 4d19h
[root@hdss7-21 ~]# kubectl get ns
NAME STATUS AGE
default Active 4d19h
kube-node-lease Active 4d19h
kube-public Active 4d19h
kube-system Active 4d19h
查看名称空间内的资源
[root@hdss7-21 ~]# kubectl get all -n default NAME READY STATUS RESTARTS AGE pod/nginx-ds-7hg9l 1/1 Running 0 3d18h pod/nginx-ds-tnhsg 1/1 Running 0 3d18h NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes ClusterIP 192.168.0.1 <none> 443/TCP 4d19h NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE daemonset.apps/nginx-ds 2 2 2 2 2 <none> 3d18h
创建名称空间
[root@hdss7-21 ~]# kubectl create namespace app namespace/app created [root@hdss7-21 ~]# kubectl get namespace NAME STATUS AGE app Active 35s default Active 4d20h kube-node-lease Active 4d20h kube-public Active 4d20h kube-system Active 4d20h
删除名称空间
[root@hdss7-21 ~]# kubectl delete ns app namespace "app" deleted [root@hdss7-21 ~]# kubectl get ns NAME STATUS AGE default Active 4d20h kube-node-lease Active 4d20h kube-public Active 4d20h kube-system Active 4d20h
1.1.2.管理Deployment资源
创建deployment
[root@hdss7-21 ~]# kubectl create deployment nginx-dp --image=harbor.fx.com/public/nginx:v1.7.9 -n kube-public
deployment.apps/nginx-dp created
查看deployment
- 简单查看
[root@hdss7-21 ~]# kubectl get deployment -n kube-public NAME READY UP-TO-DATE AVAILABLE AGE nginx-dp 1/1 1 1 56s
- 扩展查看
[root@hdss7-21 ~]# kubectl get deployment -n kube-public -o wide NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR nginx-dp 1/1 1 1 20m nginx harbor.fx.com/public/nginx:v1.7.9 app=nginx-dp
- 详细查看
[root@hdss7-21 ~]# kubectl describe deployment nginx-dp -n kube-public Name: nginx-dp Namespace: kube-public CreationTimestamp: Mon, 08 Jun 2020 11:40:54 +0800 Labels: app=nginx-dp Annotations: deployment.kubernetes.io/revision: 1 Selector: app=nginx-dp 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=nginx-dp Containers: nginx: Image: harbor.fx.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: nginx-dp-6f4ddd775 (1/1 replicas created) Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal ScalingReplicaSet 6m31s deployment-controller Scaled up replica set nginx-dp-6f4ddd775 to 1
查看pod资源
- 简单查找
[root@hdss7-21 ~]# kubectl get pods -n kube-public NAME READY STATUS RESTARTS AGE nginx-dp-6f4ddd775-98dbq 1/1 Running 0 107m
- 扩展查找
[root@hdss7-21 ~]# kubectl get pods -n kube-public -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nginx-dp-6f4ddd775-98dbq 1/1 Running 0 108m 172.7.21.3 hdss7-21.host.com <none> <none>
- 扩展查找
[root@hdss7-21 ~]# kubectl describe pods nginx-dp-6f4ddd775-98dbq -n kube-public Name: nginx-dp-6f4ddd775-98dbq Namespace: kube-public Priority: 0 Node: hdss7-21.host.com/10.4.7.21 Start Time: Mon, 08 Jun 2020 11:40:54 +0800 Labels: app=nginx-dp pod-template-hash=6f4ddd775 Annotations: <none> Status: Running IP: 172.7.21.3 Controlled By: ReplicaSet/nginx-dp-6f4ddd775 Containers: nginx: Container ID: docker://93213abdbfb595ebe213c6764f0af4932a40c2ceaa5efc562fac9f2cde5b69fe Image: harbor.fx.com/public/nginx:v1.7.9 Image ID: docker-pullable://harbor.fx.com/public/nginx@sha256:b1f5935eb2e9e2ae89c0b3e2e148c19068d91ca502e857052f14db230443e4c2 Port: <none> Host Port: <none> State: Running Started: Mon, 08 Jun 2020 11:40:56 +0800 Ready: True Restart Count: 0 Environment: <none> Mounts: /var/run/secrets/kubernetes.io/serviceaccount from default-token-zld8g (ro) Conditions: Type Status Initialized True Ready True ContainersReady True PodScheduled True Volumes: default-token-zld8g: Type: Secret (a volume populated by a Secret) SecretName: default-token-zld8g Optional: false QoS Class: BestEffort Node-Selectors: <none> Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s node.kubernetes.io/unreachable:NoExecute for 300s Events: <none>
进入pod资源
[root@hdss7-21 ~]# kubectl exec -it nginx-dp-6f4ddd775-98dbq /bin/bash -n kube-public root@nginx-dp-6f4ddd775-98dbq:/#
注：也可以使用docker exec进入容器
删除pod资源(重启)
[root@hdss7-21 ~]# kubectl delete pods nginx-dp-6f4ddd775-98dbq -n kube-public pod "nginx-dp-6f4ddd775-98dbq" deleted
强制删除参数: --force-grace-period=0
删除deployment
[root@hdss7-21 ~]# kubectl delete deployment nginx-dp -n kube-public deployment.extensions "nginx-dp" deleted
[root@hdss7-21 ~]# kubectl get deployment -n kube-public No resources found.
[root@hdss7-21 ~]# kubectl get pods -n kube-public No resources found.
1.1.3 管理Service资源
创建Service
[root@hdss7-21 ~]# kubectl create deployment nginx-dp --image=harbor.fx.com/public/nginx:v1.7.9 -n kube-public deployment.apps/nginx-dp created [root@hdss7-21 ~]# kubectl expose deployment nginx-dp --port=80 -n kube-public service/nginx-dp exposed [root@hdss7-21 ~]# kubectl scale deployment nginx-dp --replicas=2 -n kube-public deployment.extensions/nginx-dp scaled [root@hdss7-21 ~]# 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 -> 10.4.7.21:6443 Masq 1 0 0 -> 10.4.7.22:6443 Masq 1 0 0 TCP 192.168.164.107:80 nq -> 172.7.21.3:80 Masq 1 0 0 -> 172.7.22.3:80 Masq 1 0 0 [root@hdss7-21 ~]# kubectl get service -n kube-public NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nginx-dp ClusterIP 192.168.164.107 <none> 80/TCP 6m54s
查看service
[root@hdss7-21 ~]# kubectl describe service nginx-dp -n kube-public Name: nginx-dp Namespace: kube-public Labels: app=nginx-dp Annotations: <none> Selector: app=nginx-dp Type: ClusterIP IP: 192.168.164.107 Port: <unset> 80/TCP TargetPort: 80/TCP Endpoints: 172.7.22.3:80 Session Affinity: None Events: <none>
1.1.4.kubectl用法总结
陈述式资源管理方法小结:
- kubernetes集群管理集群的唯一入口是通过相应的方法调用apiserver的接口。
- kubectl是官方的CLI命令行工具，用于与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。
- kubectl的命令大全
- kubectl --help
- http://docs.kubernetes.org.cn/683.html
- 陈述式资源管理方法可以满足90%以上的资源管理需求，但它的缺点也很明显
- 命令冗长、复杂、难以记忆。
- 特定场景下，无法实现管理需求。
- 对资源的增、删、查操作比较容易，改就很痛苦。
1.2.声明式资源管理方法
声明式资源管理方法依赖于一资源配置清单（yaml/json）
查看资源配置清单的方法
[root@hdss7-21 ~]# kubectl get pods nginx-dp-6f4ddd775-x9hjg -o yaml -n kube-public apiVersion: v1 kind: Pod metadata: creationTimestamp: "2020-06-08T05:56:16Z" generateName: nginx-dp-6f4ddd775- labels: app: nginx-dp pod-template-hash: 6f4ddd775 name: nginx-dp-6f4ddd775-x9hjg namespace: kube-public ownerReferences: - apiVersion: apps/v1 blockOwnerDeletion: true controller: true kind: ReplicaSet name: nginx-dp-6f4ddd775 uid: 872e6838-b8ef-4a6a-8cb2-98a94dca0c91 resourceVersion: "522272" selfLink: /api/v1/namespaces/kube-public/pods/nginx-dp-6f4ddd775-x9hjg uid: 7a04423c-add2-45ee-8211-c6e80545cb9a spec: containers: - image: harbor.fx.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-zld8g readOnly: true dnsPolicy: ClusterFirst enableServiceLinks: true nodeName: hdss7-22.host.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-zld8g secret: defaultMode: 420 secretName: default-token-zld8g status: conditions: - lastProbeTime: null lastTransitionTime: "2020-06-08T05:56:16Z" status: "True" type: Initialized - lastProbeTime: null lastTransitionTime: "2020-06-08T05:56:17Z" status: "True" type: Ready - lastProbeTime: null lastTransitionTime: "2020-06-08T05:56:17Z" status: "True" type: ContainersReady - lastProbeTime: null lastTransitionTime: "2020-06-08T05:56:16Z" status: "True" type: PodScheduled containerStatuses: - containerID: docker://f5e7ac3cef3c1439df242cc2519ca22c7b942ec44099ffdd0258fed05a075dea image: harbor.fx.com/public/nginx:v1.7.9 imageID: docker-pullable://harbor.fx.com/public/nginx@sha256:b1f5935eb2e9e2ae89c0b3e2e148c19068d91ca502e857052f14db230443e4c2 lastState: {} name: nginx ready: true restartCount: 0 state: running: startedAt: "2020-06-08T05:56:17Z" hostIP: 10.4.7.22 phase: Running podIP: 172.7.22.3 qosClass: BestEffort startTime: "2020-06-08T05:56:16Z" [root@hdss7-21 ~]# kubectl get svc nginx-dp -o yaml -n kube-public apiVersion: v1 kind: Service metadata: creationTimestamp: "2020-06-08T05:58:22Z" labels: app: nginx-dp name: nginx-dp namespace: kube-public resourceVersion: "522457" selfLink: /api/v1/namespaces/kube-public/services/nginx-dp uid: df2f2bd9-bfa7-4cdb-b25b-1488e63944a9 spec: clusterIP: 192.168.164.107 ports: - port: 80 protocol: TCP targetPort: 80 selector: app: nginx-dp sessionAffinity: None type: ClusterIP status: loadBalancer: {}
解释资源配置清单
[root@hdss7-21 ~]# kubectl explain service
创建资源配置清单
[root@hdss7-21 ~]# vim nginx-ds.yaml apiVersion: v1 kind: Service metadata: labels: nginx: nginx-ds name: nginx-ds namespace: default spec: ports: - port: 80 protocol: TCP targetPort: 80 selector: app: nginx-ds type: ClusterIP
应用资源配置清单
[root@hdss7-21 ~]# kubectl create -f nginx-ds.yaml service/nginx-ds configured [root@hdss7-21 ~]# kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 192.168.0.1 <none> 443/TCP 5d1h nginx-ds ClusterIP 192.168.100.178 <none> 80/TCP 8m54s
修改资源配置清单
- 离线修改
[root@hdss7-21 ~]# docker login docker.io [root@hdss7-21 ~]# docker pull fangxing1001/nginx:curl [root@hdss7-21 ~]# vim nginx-ds.yaml apiVersion: extensions/v1beta1 kind: Deployment metadata: name: nginx-test spec: template: metadata: labels: app: nginx-test spec: containers: - name: mynginx image: harbor.fx.com/public/nginx:v1.7.9 ports: - containerPort: 80 [root@hdss7-21 ~]# kubectl apply -f nginx-ds.yaml deployment.extensions/nginx-test created [root@hdss7-21 ~]# vim nginx-ds.yaml apiVersion: extensions/v1beta1 kind: Deployment metadata: name: nginx-test spec: template: metadata: labels: app: nginx-test spec: containers: - name: mynginx image: harbor.fx.com/public/nginx:curl ports: - containerPort: 80 [root@hdss7-21 ~]# kubectl apply -f nginx-ds.yaml deployment.extensions/nginx-test configured [root@hdss7-21 ~]# kubectl describe pods nginx-test-655f555749-wwbnp Name: nginx-test-655f555749-wwbnp Namespace: default Priority: 0 Node: hdss7-22.host.com/10.4.7.22 Start Time: Mon, 08 Jun 2020 17:40:13 +0800 Labels: app=nginx-test pod-template-hash=655f555749 Annotations: <none> Status: Running IP: 172.7.22.4 Controlled By: ReplicaSet/nginx-test-655f555749 Containers: mynginx: Container ID: docker://35a16c22463b9ff05adb69bb2f3665c316c58de657ab01f9c9f63896d0d1c3f0 Image: harbor.fx.com/public/nginx:curl Image ID: docker-pullable://harbor.fx.com/public/nginx@sha256:75f7e3c69bb839f8400adbca228bce8b7e5bc3e9bce2ff1bb543094b82337e16 Port: 80/TCP Host Port: 0/TCP State: Running Started: Mon, 08 Jun 2020 17:40:22 +0800 Ready: True Restart Count: 0 Environment: <none> Mounts: /var/run/secrets/kubernetes.io/serviceaccount from default-token-zkqff (ro) Conditions: Type Status Initialized True Ready True ContainersReady True PodScheduled True Volumes: default-token-zkqff: Type: Secret (a volume populated by a Secret) SecretName: default-token-zkqff Optional: false QoS Class: BestEffort Node-Selectors: <none> Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s node.kubernetes.io/unreachable:NoExecute for 300s Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Scheduled 3m13s default-scheduler Successfully assigned default/nginx-test-655f555749-wwbnp to hdss7-22.host.com Normal Pulling 3m11s kubelet, hdss7-22.host.com Pulling image "harbor.fx.com/public/nginx:curl" Normal Pulled 3m4s kubelet, hdss7-22.host.com Successfully pulled image "harbor.fx.com/public/nginx:curl" Normal Created 3m4s kubelet, hdss7-22.host.com Created container mynginx Normal Started 3m4s kubelet, hdss7-22.host.com Started container mynginx
- 在线修改
[root@hdss7-21 ~]# kubectl edit svc nginx-ds service/nginx-ds edited [root@hdss7-21 ~]# kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 192.168.0.1 <none> 443/TCP 5d1h nginx-ds ClusterIP 192.168.100.178 <none> 80/TCP 16m
删除资源
[root@hdss7-21 ~]# kubectl delete -f nginx-ds.yaml deployment.extensions "nginx-test" deleted [root@hdss7-21 ~]# kubectl get pods NAME READY STATUS RESTARTS AGE nginx-ds-7hg9l 1/1 Running 0 4d1h nginx-ds-tnhsg 1/1 Running 0 4d1h
声明资源管理方法小结：
- 声明式资源管理方法，依赖于统一资源配置清单文件对资源进行管理。
- 对资源的管理，是通过事先定义在统一资源配置清单内，再通过陈述式命令应用到K8S集群里。
- 语法格式:kubectl create/apply/delete -f /path/to/yaml
