K8s 管理工具 kubectl 详解

文章目录

    • 一、陈述式管理
      • 1. 陈述式资源管理方法
      • 2. k8s 相关信息查看
        • 2.1 查看版本信息
        • 2.2 查看资源对象简写
        • 2.3 查看集群信息
        • 2.4 配置kubectl自动补全
        • 2.5 查看日志
        • 2.6 基本信息查看
          • 2.6.1 查看master节点状态
          • 2.6.2 查看命名空间
        • 2.7 命名空间操作
          • 2.7.1 查看default命名空间的所有资源
          • 2.7.2 创建命名空间app
          • 2.7.3 删除命名空间app
        • 2.8 deployment/pod操作
          • 2.8.1 在命名空间kube-public创建副本控制器(deployment)来启动Pod(nginx-test)
          • 2.8.2 描述某个资源的详细信息
          • 2.8.3 查看命名空间kube-public中pod信息
          • 2.8.4 登录容器
          • 2.8.5 删除(重启)pod资源
          • 2.8.6 若无法删除,总是处于terminate状态,则要强行删除pod
          • 2.8.7 扩缩容
            • 2.8.7.1 扩容
            • 2.8.7.2 缩容
          • 2.8.8 删除副本控制器
        • 2.9 增加/删除label
          • 2.9.1 增加label
          • 2.9.2 删除label
      • 3. K8S模拟项目
        • 3.1 项目的生命周期
        • 3.2 创建kubectl run命令
        • 3.3 发布kubectl expose命令
          • 3.3.1 Service的作用
          • 3.3.2 Service的类型
          • 3.3.3 查看Pod网络状态详细信息和Service暴露的端口
          • 3.3.4 查看关联后端的节点
          • 3.3.5 查看service的描述信息
          • 3.3.6 查看负载均衡端口
          • 3.3.7 访问查看
          • 3.3.8 查看访问日志
        • 3.4 更新kubectl set
          • 3.4.1 获取修改模板
          • 3.4.2 查看当前nginx的版本号
          • 3.4.3 将nginx版本更新为1.15
          • 3.4.4 监听pod状态
          • 3.4.5 查看pod的ip变化
          • 3.4.6 重新查看nginx版本号
        • 3.5 回滚kubectl rollout
          • 3.5.1 查看历史版本
          • 3.5.2 执行回滚到上一个版本
          • 3.5.3 执行回滚到指定版本
          • 3.5.4 检查回滚状态
        • 3.6 删除kubectl delete
          • 3.6.1 删除副本控制器
          • 3.6.2 删除service
      • 4. 金丝雀发布/灰度发布(Canary Release)
        • 4.1 金丝雀发布简介
        • 4.2 更新deployment的版本,并配置暂停deployment
          • 4.2.1 创建pods
          • 4.2.2 发布服务
          • 4.2.3 查看nginx版本
          • 4.2.4 定义版本CHANGE-CAUSE
            • 4.2.4.1 查看历史版本
            • 4.2.4.2 定义版本CHANGE-CAUSE
            • 4.2.4.3 再次查看历史版本
          • 4.2.5 更新nginx版本为1.15并配置暂停
          • 4.2.6 观察更新状态
          • 4.2.7 监控更新的过程
          • 4.2.8 查看nginx版本
          • 4.2.9 查看并更新历史版本change-cause
          • 4.2.10 resume继续更新
          • 4.2.11 查看最后的更新情况
    • 二、声明式管理
      • 1. 声明式管理方法
      • 2. 查看资源配置清单
      • 3. 解释资源配置清单
      • 4. 修改资源配置清单并应用
        • 4.1 离线修改
        • 4.2 在线修改
      • 5. 删除资源配置清单
        • 5.1 陈述式删除
        • 5.2 声明式删除


一、陈述式管理

1. 陈述式资源管理方法

  • kubernetes 集群管理集群资源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
    k8s官方中文文档:http://docs.kubernetes.org.cn/683.html
  • 对资源的增、删、查操作比较容易,但对改的操作就不容易了

2. k8s 相关信息查看

2.1 查看版本信息

kubectl version

[root@master ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.1", GitCommit:"4485c6f18cee9a5d3c3b4e523bd27972b1b53892", GitTreeState:"clean", BuildDate:"2019-07-18T09:18:22Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.1", GitCommit:"4485c6f18cee9a5d3c3b4e523bd27972b1b53892", GitTreeState:"clean", BuildDate:"2019-07-18T09:09:21Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"}

kubectl get nodes

[root@master ~]# kubectl get nodes 
NAME     STATUS   ROLES    AGE   VERSION
master   Ready    master   20h   v1.15.1
node01   Ready    <none>   20h   v1.15.1
node02   Ready    <none>   20h   v1.15.1

2.2 查看资源对象简写

kubectl api-resources

[root@master ~]# kubectl api-resources
NAME                              SHORTNAMES   APIGROUP                       NAMESPACED   KIND
bindings                                                                      true         Binding
componentstatuses                 cs                                          false        ComponentStatus
configmaps                        cm                                          true         ConfigMap
endpoints                         ep                                          true         Endpoints
events                            ev                                          true         Event
limitranges                       limits                                      true         LimitRange
namespaces                        ns                                          false        Namespace
nodes                             no                                          false        Node
persistentvolumeclaims            pvc                                         true         PersistentVolumeClaim
persistentvolumes                 pv                                          false        PersistentVolume
pods                              po                                          true         Pod
podtemplates                                                                  true         PodTemplate
replicationcontrollers            rc                                          true         ReplicationController
resourcequotas                    quota                                       true         ResourceQuota
secrets                                                                       true         Secret
serviceaccounts                   sa                                          true         ServiceAccount
services                          svc                                         true         Service
mutatingwebhookconfigurations                  admissionregistration.k8s.io   false        MutatingWebhookConfiguration
validatingwebhookconfigurations                admissionregistration.k8s.io   false        ValidatingWebhookConfiguration
customresourcedefinitions         crd,crds     apiextensions.k8s.io           false        CustomResourceDefinition
apiservices                                    apiregistration.k8s.io         false        APIService
controllerrevisions                            apps                           true         ControllerRevision
daemonsets                        ds           apps                           true         DaemonSet
deployments                       deploy       apps                           true         Deployment
replicasets                       rs           apps                           true         ReplicaSet
statefulsets                      sts          apps                           true         StatefulSet
tokenreviews                                   authentication.k8s.io          false        TokenReview
localsubjectaccessreviews                      authorization.k8s.io           true         LocalSubjectAccessReview
selfsubjectaccessreviews                       authorization.k8s.io           false        SelfSubjectAccessReview
selfsubjectrulesreviews                        authorization.k8s.io           false        SelfSubjectRulesReview
subjectaccessreviews                           authorization.k8s.io           false        SubjectAccessReview
horizontalpodautoscalers          hpa          autoscaling                    true         HorizontalPodAutoscaler
cronjobs                          cj           batch                          true         CronJob
jobs                                           batch                          true         Job
certificatesigningrequests        csr          certificates.k8s.io            false        CertificateSigningRequest
leases                                         coordination.k8s.io            true         Lease
events                            ev           events.k8s.io                  true         Event
daemonsets                        ds           extensions                     true         DaemonSet
deployments                       deploy       extensions                     true         Deployment
ingresses                         ing          extensions                     true         Ingress
networkpolicies                   netpol       extensions                     true         NetworkPolicy
podsecuritypolicies               psp          extensions                     false        PodSecurityPolicy
replicasets                       rs           extensions                     true         ReplicaSet
ingresses                         ing          networking.k8s.io              true         Ingress
networkpolicies                   netpol       networking.k8s.io              true         NetworkPolicy
runtimeclasses                                 node.k8s.io                    false        RuntimeClass
poddisruptionbudgets              pdb          policy                         true         PodDisruptionBudget
podsecuritypolicies               psp          policy                         false        PodSecurityPolicy
clusterrolebindings                            rbac.authorization.k8s.io      false        ClusterRoleBinding
clusterroles                                   rbac.authorization.k8s.io      false        ClusterRole
rolebindings                                   rbac.authorization.k8s.io      true         RoleBinding
roles                                          rbac.authorization.k8s.io      true         Role
priorityclasses                   pc           scheduling.k8s.io              false        PriorityClass
csidrivers                                     storage.k8s.io                 false        CSIDriver
csinodes                                       storage.k8s.io                 false        CSINode
storageclasses                    sc           storage.k8s.io                 false        StorageClass
volumeattachments                              storage.k8s.io                 false        VolumeAttachment

2.3 查看集群信息

kubectl cluster-info

[root@master ~]# kubectl cluster-info
Kubernetes master is running at https://192.168.122.10:6443
KubeDNS is running at https://192.168.122.10:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
 
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

2.4 配置kubectl自动补全

source <(kubectl completion bash)

[root@master ~]# source <(kubectl completion bash)

可通过TAB键实现命令补全,建议将其写入 /etc/profile

2.5 查看日志

journalctl -u kubelet -f

[root@master ~]# journalctl -u kubelet -f
-- Logs begin at 一 2021-11-01 18:58:09 CST. --
......

2.6 基本信息查看

kubectl get [-o wide|json|yaml] [-n namespace]
获取资源的相关信息,-n指定命名空间,-o指定输出格式
resource可以是具体资源名称,如"pod nhinx-xxx";也可以是资源类型,如“pod,node,svc,deploy”多种资源使用逗号间隔;或者all(仅展示几种核心资源,并不完整)
–all-namespaces或-A:表示显示所有命名空间
–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

2.6.1 查看master节点状态

kubectl get componentstatuses
kubectl get cs

[root@master ~]# kubectl get componentstatuses
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
[root@master ~]# kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
2.6.2 查看命名空间

kubectl get namespace
kubectl get ns

[root@master ~]# kubectl get namespace
NAME              STATUS   AGE
default           Active   26h
kube-node-lease   Active   26h
kube-public       Active   26h
kube-system       Active   26h
[root@master ~]# kubectl get ns
NAME              STATUS   AGE
default           Active   26h
kube-node-lease   Active   26h
kube-public       Active   26h
kube-system       Active   26h

2.7 命名空间操作

2.7.1 查看default命名空间的所有资源

kubectl get all [-n default]
由于deafult为缺省空间,当不指定命名空间时默认查看default命名空间

[root@node1 ~]# kubectl get all
NAME                 TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.244.64.1   <none>        443/TCP   4h36m
2.7.2 创建命名空间app

kubectl create ns app

[root@node1 ~]# kubectl create ns app
namespace/app created
[root@node1 ~]# kubectl get ns
NAME                   STATUS   AGE
app                    Active   3s
default                Active   4h37m
ingress-controller     Active   4h34m
kube-node-lease        Active   4h37m
kube-public            Active   4h37m
kube-system            Active   4h37m
kubernetes-dashboard   Active   4h33m
2.7.3 删除命名空间app

kubectl delete ns app

[root@node1 ~]# kubectl delete ns app
namespace "app" deleted
[root@node1 ~]# kubectl get ns
NAME                   STATUS   AGE
default                Active   4h37m
ingress-controller     Active   4h35m
kube-node-lease        Active   4h37m
kube-public            Active   4h37m
kube-system            Active   4h37m
kubernetes-dashboard   Active   4h33m

2.8 deployment/pod操作

2.8.1 在命名空间kube-public创建副本控制器(deployment)来启动Pod(nginx-test)

kubectl create deployment nginx-test --image=nginx -n kube-public

[root@node1 ~]# kubectl get pod -n kube-public
No resources found in kube-public namespace.
[root@node1 ~]# kubectl create deployment nginx-test --image=nginx -n kube-public 
deployment.apps/nginx-test created
[root@node1 ~]# kubectl get deploy -n kube-public
NAME         READY   UP-TO-DATE   AVAILABLE   AGE
nginx-test   0/1     1            0           23s
[root@node1 ~]# kubectl get deploy -n kube-public
NAME         READY   UP-TO-DATE   AVAILABLE   AGE
nginx-test   1/1     1            1           2m24s
[root@node1 ~]# kubectl get pod -n kube-public
NAME                          READY   STATUS    RESTARTS   AGE
nginx-test-795d659f45-n4nks   1/1     Running   0          2m58s
2.8.2 描述某个资源的详细信息

kubectl describe deployment nginx-test -n kube-public

[root@node1 ~]# kubectl describe deployment nginx-test -n kube-public 
Name:                   nginx-test
Namespace:              kube-public
CreationTimestamp:      Thu, 16 Dec 2021 20:35:23 +0800
Labels:                 app=nginx-test
Annotations:            deployment.kubernetes.io/revision: 1
Selector:               app=nginx-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=nginx-test
  Containers:
   nginx:
    Image:        nginx
    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-test-795d659f45 (1/1 replicas created)
Events:
  Type    Reason             Age    From                   Message
  ----    ------             ----   ----                   -------
  Normal  ScalingReplicaSet  4m26s  deployment-controller  Scaled up replica set nginx-test-795d659f45 to 1

kubectl describe pod nginx-test -n kube-public

[root@node1 ~]# kubectl describe pod nginx-test -n kube-public
......
2.8.3 查看命名空间kube-public中pod信息

kubectl get pods -n kube-public

[root@node1 ~]# kubectl get pod -n kube-public 
NAME                          READY   STATUS    RESTARTS   AGE
nginx-test-795d659f45-n4nks   1/1     Running   0          6m4s
2.8.4 登录容器

kubectl exec 可以跨主机登录容器,docker exec 只能在容器所在主机登录

[root@node1 ~]# kubectl exec -it nginx-test-795d659f45-n4nks bash -n kube-public 
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
root@nginx-test-795d659f45-n4nks:/# ls
bin   dev		   docker-entrypoint.sh  home  lib64  mnt  proc  run   srv  tmp  var
boot  docker-entrypoint.d  etc			 lib   media  opt  root  sbin  sys  usr
2.8.5 删除(重启)pod资源

由于存在 deployment/rc 之类的副本控制器,删除 pod 也会重新拉起来

[root@node1 ~]# kubectl get pod -n kube-public 
NAME                          READY   STATUS    RESTARTS   AGE
nginx-test-795d659f45-n4nks   1/1     Running   0          12m
[root@node1 ~]# kubectl delete pod nginx-test-795d659f45-n4nks -n kube-public 
pod "nginx-test-795d659f45-n4nks" deleted
[root@node1 ~]# kubectl get pod -n kube-public 
NAME                          READY   STATUS    RESTARTS   AGE
nginx-test-795d659f45-65pwr   1/1     Running   0          11s
2.8.6 若无法删除,总是处于terminate状态,则要强行删除pod

kubectl delete pod [] -n [] --force --grace-period=0
grace-period表示过渡存活期,默认30s,在删除pod之前允许pod慢慢终止其上的容器进程,从而优雅的退出,0表示立即终止pod

[root@node1 ~]# kubectl get pod -n kube-public 
NAME                          READY   STATUS    RESTARTS   AGE
nginx-test-795d659f45-r2jwz   1/1     Running   0          13s
[root@node1 ~]# kubectl delete pod nginx-test-795d659f45-r2jwz -n kube-public --force --grace-period=0
warning: Immediate deletion does not wait for confirmation that the running resource has been terminated. The resource may continue to run on the cluster indefinitely.
pod "nginx-test-795d659f45-r2jwz" force deleted
[root@node1 ~]# kubectl get pod -n kube-public 
NAME                          READY   STATUS              RESTARTS   AGE
nginx-test-795d659f45-6h9kj   0/1     ContainerCreating   0          9s
2.8.7 扩缩容
2.8.7.1 扩容

kubectl scale deployment nginx-test --replicas=3 -n kube-public

[root@node1 ~]# kubectl scale deployment nginx-test --replicas=3 -n kube-public
deployment.apps/nginx-test scaled
[root@node1 ~]# kubectl get pod -n kube-public 
NAME                          READY   STATUS              RESTARTS   AGE
nginx-test-795d659f45-6h9kj   1/1     Running             0          7m
nginx-test-795d659f45-gl6z2   0/1     ContainerCreating   0          101s
nginx-test-795d659f45-p2q9s   0/1     ContainerCreating   0          101s
2.8.7.2 缩容

kubectl scale deployment nginx-test --replicas=1 -n kube-public

[root@node1 ~]# kubectl scale deployment nginx-test --replicas=1 -n kube-public 
deployment.apps/nginx-test scaled
[root@node1 ~]# kubectl get pod -n kube-public 
NAME                          READY   STATUS        RESTARTS   AGE
nginx-test-795d659f45-6h9kj   1/1     Running       0          8m4s
nginx-test-795d659f45-gl6z2   0/1     Terminating   0          2m45s
nginx-test-795d659f45-p2q9s   0/1     Terminating   0          2m45s
[root@node1 ~]# kubectl get pod -n kube-public 
NAME                          READY   STATUS    RESTARTS   AGE
nginx-test-795d659f45-6h9kj   1/1     Running   0          8m19s
2.8.8 删除副本控制器

kubectl delete deployment nginx-test -n kube-public
kubectl delete deployment/nginx-test -n kube-public

[root@node1 ~]# kubectl delete deployment nginx-test -n kube-public
deployment.apps "nginx-test" deleted
[root@node1 ~]# kubectl get pod -n kube-public 
NAME                          READY   STATUS        RESTARTS   AGE
nginx-test-795d659f45-6h9kj   0/1     Terminating   0          8m46s
[root@node1 ~]# kubectl get pod -n kube-public 
No resources found in kube-public namespace.

2.9 增加/删除label

2.9.1 增加label

kubectl label deploy nginx-test version=nginx1.14

[root@master ~]# kubectl get deploy --show-labels
NAME         READY   UP-TO-DATE   AVAILABLE   AGE   LABELS
nginx-test   3/3     3            3           19m   run=nginx-test
[root@master ~]# kubectl label deploy nginx-test version=nginx1.14
deployment.extensions/nginx-test labeled
[root@master ~]# kubectl get deploy --show-labels
NAME         READY   UP-TO-DATE   AVAILABLE   AGE   LABELS
nginx-test   3/3     3            3           19m   run=nginx-test,version=nginx1.14
2.9.2 删除label

kubectl label deploy nginx-test version-

[root@master ~]# kubectl get deploy --show-labels
NAME         READY   UP-TO-DATE   AVAILABLE   AGE   LABELS
nginx-test   3/3     3            3           19m   run=nginx-test,version=nginx1.14
[root@master ~]# kubectl label deploy nginx-test version-
deployment.extensions/nginx-test labeled
[root@master ~]# kubectl get deploy --show-labels
NAME         READY   UP-TO-DATE   AVAILABLE   AGE   LABELS
nginx-test   3/3     3            3           20m   run=nginx-test

3. K8S模拟项目

K8S 模拟项目 pod 发布

3.1 项目的生命周期

创建–>发布–>更新–>回滚–>删除

3.2 创建kubectl run命令

● 创建并运行一个或多个容器镜像
● 创建一个deployment或job来管理容器
kubectl run --help查看使用帮助

启动nginx实例,暴露容器端口80,设置副本数3
kubectl run nginx --image=nginx:1.14 --port=80 --replicas=3

[root@master ~]# kubectl run nginx --image=nginx:1.14 --port=80 --replicas=3
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/nginx created

kubectl get pods

[root@master ~]# kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
nginx-65fc77987d-cwvwl   1/1     Running   0          7s
nginx-65fc77987d-m7cnn   1/1     Running   0          7s
nginx-65fc77987d-z7hvx   1/1     Running   0          7s

kubectl get all

[root@master ~]# kubectl get all
NAME                         READY   STATUS    RESTARTS   AGE
pod/nginx-65fc77987d-cwvwl   1/1     Running   0          24s
pod/nginx-65fc77987d-m7cnn   1/1     Running   0          24s
pod/nginx-65fc77987d-z7hvx   1/1     Running   0          24s


NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.1.0.1     <none>        443/TCP   82s


NAME                    READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/nginx   3/3     3            3           24s

NAME                               DESIRED   CURRENT   READY   AGE
replicaset.apps/nginx-65fc77987d   3         3         3       24s

3.3 发布kubectl expose命令

● 将资源暴露为新的Service
kubectl expose --help查看使用帮助

为Deployment的nginx创建Service,并通过Service的80端口转发至容器的80端口上,Service的名称为nginx-service,类型为NodePort
kubectl expose deployment nginx --port=80 --target-port=80 --name=nginx-service --type=NodePort

[root@master ~]# kubectl expose deployment nginx --port=80 --target-port=80 --name=nginx-service --type=NodePort
service/nginx-service exposed
3.3.1 Service的作用

Kubernetes之所以需要Service,一方面是因为Pod的IP不是固定的(Pod可能会重建),另一方面是因为一组Pod实例之间总会有负载均衡的需求。
Service通过Label Selector实现的对一组的Pod的访问。
对于容器应用而言,Kubernetes提供了基于VIP(虚拟IP)的网桥的方式访问Service,再由Service重定向到相应的Pod。

3.3.2 Service的类型

K8s 管理工具 kubectl 详解_第1张图片
● ClusterIP:提供一个集群内部的虚拟IP以供Pod访问(Service默认类型)
● NodePort:在每个Node上打开一个端口以供外部访问,Kubernetes将会在每个Node上打开一个端口并且每个Node的端口都是一样的,通过NodeIP:NodePort的方式
● LoadBalancer:通过外部的负载均衡器来访问,通常在云平台部署LoadBalancer还需要额外的费用。

3.3.3 查看Pod网络状态详细信息和Service暴露的端口

kubectl get pods,svc -o wide

[root@master ~]# kubectl get pods,svc -o wide
NAME                         READY   STATUS    RESTARTS   AGE   IP            NODE     NOMINATED NODE   READINESS GATES
pod/nginx-65fc77987d-cwvwl   1/1     Running   0          61s   10.244.1.25   node01   <none>           <none>
pod/nginx-65fc77987d-m7cnn   1/1     Running   0          61s   10.244.1.24   node01   <none>           <none>
pod/nginx-65fc77987d-z7hvx   1/1     Running   0          61s   10.244.2.15   node02   <none>           <none>

NAME                    TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE    SELECTOR
service/kubernetes      ClusterIP   10.1.0.1       <none>        443/TCP        119s   <none>
service/nginx-service   NodePort    10.1.155.154   <none>        80:32107/TCP   15s    run=nginx
3.3.4 查看关联后端的节点

kubectl get endpoints

[root@master ~]# kubectl get endpoints
NAME            ENDPOINTS                                      AGE
kubernetes      192.168.122.10:6443                            15m
nginx-service   10.244.1.24:80,10.244.1.25:80,10.244.2.15:80   13m
3.3.5 查看service的描述信息

kubectl describe svc nginx

[root@master ~]# kubectl describe svc nginx
Name:                     nginx-service
Namespace:                default
Labels:                   run=nginx
Annotations:              <none>
Selector:                 run=nginx
Type:                     NodePort
IP:                       10.1.155.154
Port:                     <unset>  80/TCP
TargetPort:               80/TCP
NodePort:                 <unset>  32107/TCP
Endpoints:                10.244.1.24:80,10.244.1.25:80,10.244.2.15:80
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>
3.3.6 查看负载均衡端口

在node01节点上操作

[root@node01 ~]# yum install -y ipvsadm
[root@node01 ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
......      
TCP  192.168.122.11:32107 rr
#外部访问的IP和端口
  -> 10.244.1.24:80               Masq    1      0          0         
  -> 10.244.1.25:80               Masq    1      0          0         
  -> 10.244.2.15:80               Masq    1      0          0         
......        
TCP  10.1.155.154:80 rr
#pod集群组内部访问的IP和端口
  -> 10.244.1.24:80               Masq    1      0          0         
  -> 10.244.1.25:80               Masq    1      0          0         
  -> 10.244.2.15:80               Masq    1      0          0                
......     

在node02节点上操作

[root@node02 ~]# yum install -y ipvsadm
[root@node02 ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
......
TCP  192.168.122.12:32107 rr
#外部访问的IP和端口
  -> 10.244.1.24:80               Masq    1      0          0         
  -> 10.244.1.25:80               Masq    1      0          0         
  -> 10.244.2.15:80               Masq    1      0          0         
......
TCP  10.1.155.154:80 rr
#pod集群组内部访问的IP和端口
  -> 10.244.1.24:80               Masq    1      0          0         
  -> 10.244.1.25:80               Masq    1      0          0         
  -> 10.244.2.15:80               Masq    1      0          0         
......
3.3.7 访问查看

curl 10.1.155.154

[root@master ~]# curl 10.1.155.154
<!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>
<h1>Welcome to nginx!</h1>
<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>

curl 192.168.122.11:32107

[root@master ~]# curl 192.168.122.11:32107
<!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>
<h1>Welcome to nginx!</h1>
<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>
3.3.8 查看访问日志
[root@master ~]# kubectl logs nginx-65fc77987d-cwvwl
10.244.0.0 - - [02/Nov/2021:12:58:38 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.29.0" "-"
[root@master ~]# kubectl logs nginx-65fc77987d-m7cnn
10.244.1.1 - - [02/Nov/2021:13:00:06 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.29.0" "-"
[root@master ~]# kubectl logs nginx-65fc77987d-z7hvx
10.244.2.1 - - [02/Nov/2021:13:00:10 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.29.0" "-"

3.4 更新kubectl set

● 更改现有应用资源一些信息。
kubectl set --help查看使用帮助

3.4.1 获取修改模板

kubectl set image --help获取

[root@master ~]# kubectl set image --help
......
Examples:
  # Set a deployment's nginx container image to 'nginx:1.9.1', and its busybox container image to 'busybox'.
  kubectl set image deployment/nginx busybox=busybox nginx=nginx:1.9.1
......
3.4.2 查看当前nginx的版本号
[root@master ~]# curl -I 192.168.122.11:32107
#通过报文头查看版本号
HTTP/1.1 200 OK
Server: nginx/1.14.2
#nginx版本号为1.14.2
Date: Tue, 02 Nov 2021 13:10:49 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 04 Dec 2018 14:44:49 GMT
Connection: keep-alive
ETag: "5c0692e1-264"
Accept-Ranges: bytes
3.4.3 将nginx版本更新为1.15

kubectl set image deployment/nginx nginx=nginx:1.15

[root@master ~]# kubectl set image deployment/nginx nginx=nginx:1.15
deployment.extensions/nginx image updated
3.4.4 监听pod状态

处于动态监听pod状态,由于使用的是滚动更新方式,所以会先生成一个新的pod,然后删除一个旧的pod,往后以此类推
kubectl get pods -w

[root@master ~]# kubectl get pods -w
NAME                     READY   STATUS              RESTARTS   AGE
nginx-65fc77987d-cwvwl   1/1     Running             0          62m
nginx-65fc77987d-m7cnn   1/1     Running             0          62m
nginx-65fc77987d-z7hvx   1/1     Running             0          62m
nginx-6cbd4b987c-65qtx   0/1     ContainerCreating   0          23s
#新建第一个pod
nginx-6cbd4b987c-65qtx   1/1     Running             0          24s
nginx-65fc77987d-cwvwl   1/1     Terminating         0          63m
#第一个新pod运行后,删除一个旧pod
nginx-6cbd4b987c-27qz7   0/1     Pending             0          0s
nginx-6cbd4b987c-27qz7   0/1     Pending             0          0s
nginx-6cbd4b987c-27qz7   0/1     ContainerCreating   0          0s
#新建第二个pod
nginx-65fc77987d-cwvwl   0/1     Terminating         0          63m
nginx-65fc77987d-cwvwl   0/1     Terminating         0          63m
nginx-65fc77987d-cwvwl   0/1     Terminating         0          63m
nginx-6cbd4b987c-27qz7   1/1     Running             0          8s
nginx-65fc77987d-m7cnn   1/1     Terminating         0          63m
#第二个新pod运行后,删除第二个旧pod
nginx-6cbd4b987c-m467f   0/1     Pending             0          0s
nginx-6cbd4b987c-m467f   0/1     Pending             0          0s
nginx-6cbd4b987c-m467f   0/1     ContainerCreating   0          0s
#新建第三个pod
nginx-65fc77987d-m7cnn   0/1     Terminating         0          63m
nginx-6cbd4b987c-m467f   1/1     Running             0          2s
nginx-65fc77987d-z7hvx   1/1     Terminating         0          63m
#第三个新pod运行后,删除第三个旧pod
nginx-65fc77987d-z7hvx   0/1     Terminating         0          63m
nginx-65fc77987d-m7cnn   0/1     Terminating         0          63m
nginx-65fc77987d-m7cnn   0/1     Terminating         0          63m
nginx-65fc77987d-z7hvx   0/1     Terminating         0          63m
nginx-65fc77987d-z7hvx   0/1     Terminating         0          63m

更新规则可通过“kubetl describe deployment nginx”的“RollingUpdateStrategy”查看,默认配置为“25% max unavailable, 25% max surge”,即按照25%的比例进行滚动更新。

3.4.5 查看pod的ip变化

kubectl get pod -o wide

[root@master ~]# kubectl get pod -o wide
NAME                     READY   STATUS    RESTARTS   AGE     IP            NODE     NOMINATED NODE   READINESS GATES
nginx-6cbd4b987c-27qz7   1/1     Running   0          6m19s   10.244.2.16   node02   <none>           <none>
nginx-6cbd4b987c-65qtx   1/1     Running   0          6m43s   10.244.1.26   node01   <none>           <none>
nginx-6cbd4b987c-m467f   1/1     Running   0          6m11s   10.244.1.27   node01   <none>           <none>

pod更新后,ip改变

3.4.6 重新查看nginx版本号
[root@master ~]# curl -I 192.168.122.11:32107
HTTP/1.1 200 OK
Server: nginx/1.15.12
#nginx版本更新为1.15.12
Date: Tue, 02 Nov 2021 13:22:29 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 16 Apr 2019 13:08:19 GMT
Connection: keep-alive
ETag: "5cb5d3c3-264"
Accept-Ranges: bytes

3.5 回滚kubectl rollout

● 对资源进行回滚管理
kubectl rollout --help查看使用帮助

3.5.1 查看历史版本

kubectl rollout history deployment/nginx

[root@master ~]# kubectl rollout history deployment/nginx
deployment.extensions/nginx 
REVISION  CHANGE-CAUSE
1         <none>
2         <none>
3.5.2 执行回滚到上一个版本

kubectl rollout undo deployment/nginx

[root@master ~]# kubectl rollout undo deployment/nginx
deployment.extensions/nginx rolled back

查看pod的ip变化

[root@master ~]# kubectl get pods -o wide
NAME                     READY   STATUS    RESTARTS   AGE   IP            NODE     NOMINATED NODE   READINESS GATES
#回滚后ip再次改变
nginx-65fc77987d-2525z   1/1     Running   0          42s   10.244.2.17   node02   <none>           <none>
nginx-65fc77987d-9qkzp   1/1     Running   0          40s   10.244.2.18   node02   <none>           <none>
nginx-65fc77987d-qg75q   1/1     Running   0          41s   10.244.1.28   node01   <none>           <none>

查看当前nginx版本

[root@master ~]# curl -I 192.168.122.11:32107
HTTP/1.1 200 OK
Server: nginx/1.14.2
#nginx版本回到1.14.2
Date: Tue, 02 Nov 2021 13:31:35 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 04 Dec 2018 14:44:49 GMT
Connection: keep-alive
ETag: "5c0692e1-264"
Accept-Ranges: bytes
3.5.3 执行回滚到指定版本

查看历史版本

[root@master ~]# kubectl rollout history deployment/nginx
deployment.extensions/nginx 
REVISION  CHANGE-CAUSE
2         <none>
3         <none>

回到revison2,即1.15版本
kubectl rollout undo deployment/nginx --to-revision=2

[root@master ~]# kubectl rollout undo deployment/nginx --to-revision=2
deployment.extensions/nginx rolled back

查看pod的ip变化

[root@master ~]# kubectl get pods -o wide
NAME                     READY   STATUS    RESTARTS   AGE   IP            NODE     NOMINATED NODE   READINESS GATES
#回滚后ip再次改变
nginx-6cbd4b987c-mhqbc   1/1     Running   0          37s   10.244.1.29   node01   <none>           <none>
nginx-6cbd4b987c-tf462   1/1     Running   0          36s   10.244.2.19   node02   <none>           <none>
nginx-6cbd4b987c-z86d6   1/1     Running   0          35s   10.244.1.30   node01   <none>           <none>

查看当前nginx版本

[root@master ~]# curl -I 192.168.122.11:32107
HTTP/1.1 200 OK
Server: nginx/1.15.12
#nginx版本回到1.15.12
Date: Tue, 02 Nov 2021 13:36:42 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 16 Apr 2019 13:08:19 GMT
Connection: keep-alive
ETag: "5cb5d3c3-264"
Accept-Ranges: bytes
3.5.4 检查回滚状态

kubectl rollout status deployment/nginx

[root@master ~]# kubectl rollout status deployment/nginx
deployment "nginx" successfully rolled out

3.6 删除kubectl delete

3.6.1 删除副本控制器

kubectl delete deployment/nginx

[root@master ~]# kubectl get deploy
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   3/3     3            3           88m
[root@master ~]# kubectl delete deployment/nginx
deployment.extensions "nginx" deleted
[root@master ~]# kubectl get deploy
No resources found.
3.6.2 删除service

kubectl delete svc/nginx-service

[root@master ~]# kubectl get svc
NAME            TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
kubernetes      ClusterIP   10.1.0.1       <none>        443/TCP        91m
nginx-service   NodePort    10.1.155.154   <none>        80:32107/TCP   89m
[root@master ~]# kubectl delete svc/nginx-service
service "nginx-service" deleted
[root@master ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.1.0.1     <none>        443/TCP   91m
[root@master ~]# kubectl get all


NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.1.0.1     <none>        443/TCP   92m

4. 金丝雀发布/灰度发布(Canary Release)

4.1 金丝雀发布简介

Deployment控制器支持自定义控制更新过程中的滚动节奏,如“暂停(pause)”或“继续(resume)”更新操作。比如等待第一批新的Pod资源创建完成后立即暂停更新过程,此时,仅存在一部分新版本的应用,主体部分还是旧的版本。然后,在筛选一小部分的用户请求路由到新版本的Pod应用,继续观察能否稳定地按期望的方式运行。确定没问题之后再继续完成余下的Pod资源滚动更新,否则立即回滚更新操作。这就是所谓的金丝雀发布。

4.2 更新deployment的版本,并配置暂停deployment

4.2.1 创建pods

kubectl run nginx-test --image=nginx:1.14 --replicas=3

[root@master ~]# kubectl run nginx-test --image=nginx:1.14 --replicas=3
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/nginx-test created
[root@master ~]# kubectl get pods,deploy -o wide
NAME                              READY   STATUS    RESTARTS   AGE   IP            NODE     NOMINATED NODE   READINESS GATES
pod/nginx-test-6cc7cd5547-4xqcb   1/1     Running   0          51s   10.244.2.23   node02   <none>           <none>
pod/nginx-test-6cc7cd5547-gcbh5   1/1     Running   0          51s   10.244.1.37   node01   <none>           <none>
pod/nginx-test-6cc7cd5547-nw6k6   1/1     Running   0          51s   10.244.1.38   node01   <none>           <none>

NAME                               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES       SELECTOR
deployment.extensions/nginx-test   3/3     3            3           51s   nginx-test   nginx:1.14   run=nginx-test
4.2.2 发布服务

kubectl expose deploy nginx-test --port=80 --target-port=80 --name=nginx-service --type=NodePort

[root@master ~]# kubectl expose deploy nginx-test --port=80 --target-port=80 --name=nginx-service --type=NodePort
service/nginx-service exposed
[root@master ~]# kubectl get svc -o wide
NAME            TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)        AGE   SELECTOR
kubernetes      ClusterIP   10.1.0.1      <none>        443/TCP        23h   <none>
nginx-service   NodePort    10.1.36.134   <none>        80:30191/TCP   9s    run=nginx-test
4.2.3 查看nginx版本
[root@master ~]# curl -I 192.168.122.11:30191
HTTP/1.1 200 OK
Server: nginx/1.14.2
#版本号为1.14.2
Date: Wed, 03 Nov 2021 11:54:11 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 04 Dec 2018 14:44:49 GMT
Connection: keep-alive
ETag: "5c0692e1-264"
Accept-Ranges: bytes
4.2.4 定义版本CHANGE-CAUSE
4.2.4.1 查看历史版本

在不定义CHANGE-CAUSE的情况下,缺省值为,当历史版本较多时,不便于咱们回滚时辨认版本号。因此,建议定义CHANGE-CAUSE为服务版本以帮助咱们辨认当前服务。
kubectl rollout history deploy/nginx-test

[root@master ~]# kubectl rollout history deploy/nginx-test
deployment.extensions/nginx-test 
REVISION  CHANGE-CAUSE
1         <none>
4.2.4.2 定义版本CHANGE-CAUSE

一般通过修改配置的方式定义change-cause

[root@master ~]# kubectl edit deploy/nginx-test

......
kind: Deployment
metadata:
  annotations:
#下行可定义历史版本revision
    deployment.kubernetes.io/revision: "1"
#在Deployment的matadata项下的annotations中如下行定义change-cause
    kubernetes.io/change-cause: "nginx1.14"
......
4.2.4.3 再次查看历史版本
[root@master ~]# kubectl rollout history deploy/nginx-test
deployment.extensions/nginx-test 
REVISION  CHANGE-CAUSE
1         nginx1.14
4.2.5 更新nginx版本为1.15并配置暂停

kubectl set image deploy/nginx-test nginx-test=nginx:1.15 && kubectl rollout pause deploy/nginx-test

[root@master ~]# kubectl set image deploy/nginx-test nginx-test=nginx:1.15 && kubectl rollout pause deploy/nginx-test
deployment.extensions/nginx-test image updated
deployment.extensions/nginx-test paused
4.2.6 观察更新状态

kubectl rollout status deploy/nginx-test

[root@master ~]# kubectl rollout status deploy/nginx-test
Waiting for deployment "nginx-test" rollout to finish: 1 out of 3 new replicas have been updated...
4.2.7 监控更新的过程

可以看到已经新增了一个pod,但是并未按照预期的状态去删除一个旧的资源,就是因为使用了pause暂停命令
kubectl get pods -w

[root@master ~]# kubectl get pod -o wide
NAME                          READY   STATUS    RESTARTS   AGE     IP            NODE     NOMINATED NODE   READINESS GATES
nginx-test-679dcbd68d-zw8w5   1/1     Running   0          8m28s   10.244.2.24   node02   <none>           <none>
nginx-test-6cc7cd5547-4xqcb   1/1     Running   0          48m     10.244.2.23   node02   <none>           <none>
nginx-test-6cc7cd5547-gcbh5   1/1     Running   0          48m     10.244.1.37   node01   <none>           <none>
nginx-test-6cc7cd5547-nw6k6   1/1     Running   0          48m     10.244.1.38   node01   <none>           <none>
4.2.8 查看nginx版本

kubectl get pod -o wide

[root@master ~]# kubectl get pod -o wide
NAME                          READY   STATUS    RESTARTS   AGE     IP            NODE     NOMINATED NODE   READINESS GATES
nginx-test-679dcbd68d-zw8w5   1/1     Running   0          8m28s   10.244.2.24   node02   <none>           <none>
nginx-test-6cc7cd5547-4xqcb   1/1     Running   0          48m     10.244.2.23   node02   <none>           <none>
nginx-test-6cc7cd5547-gcbh5   1/1     Running   0          48m     10.244.1.37   node01   <none>           <none>
nginx-test-6cc7cd5547-nw6k6   1/1     Running   0          48m     10.244.1.38   node01   <none>           <none>

查看nginx版本

[root@master ~]# curl -I 192.168.122.12:30191
HTTP/1.1 200 OK
Server: nginx/1.14.2
Date: Wed, 03 Nov 2021 12:45:37 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 04 Dec 2018 14:44:49 GMT
Connection: keep-alive
ETag: "5c0692e1-264"
Accept-Ranges: bytes

[root@master ~]# curl -I 192.168.122.12:30191
HTTP/1.1 200 OK
Server: nginx/1.14.2
Date: Wed, 03 Nov 2021 12:46:59 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 04 Dec 2018 14:44:49 GMT
Connection: keep-alive
ETag: "5c0692e1-264"
Accept-Ranges: bytes

[root@master ~]# curl -I 192.168.122.12:30191
HTTP/1.1 200 OK
Server: nginx/1.14.2
Date: Wed, 03 Nov 2021 12:47:09 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 04 Dec 2018 14:44:49 GMT
Connection: keep-alive
ETag: "5c0692e1-264"
Accept-Ranges: bytes

[root@master ~]# curl -I 192.168.122.12:30191
HTTP/1.1 200 OK
Server: nginx/1.15.12
#新pod为1.15
Date: Wed, 03 Nov 2021 12:47:12 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 16 Apr 2019 13:08:19 GMT
Connection: keep-alive
ETag: "5cb5d3c3-264"
Accept-Ranges: bytes
4.2.9 查看并更新历史版本change-cause

kubectl rollout history deploy/nginx-test

[root@master ~]# kubectl rollout history deploy/nginx-test
deployment.extensions/nginx-test 
REVISION  CHANGE-CAUSE
1         nginx1.14
2         nginx1.14

kubectl edit deploy/nginx-test

[root@master ~]# kubectl edit deploy/nginx-test

kind: Deployment
metadata:
  annotations:
#下行的revison自动更新为2
    deployment.kubernetes.io/revision: "2"
#修改下行的change-cause为nginx1.15
    kubernetes.io/change-cause: nginx1.15

kubectl rollout history deploy/nginx-test

[root@master ~]# kubectl rollout history deploy/nginx-test
deployment.extensions/nginx-test 
REVISION  CHANGE-CAUSE
1         nginx1.14
2         nginx1.15
4.2.10 resume继续更新

测试新版本没问题继续更新
kubectl rollout resume deploy/nginx-test

[root@master ~]# kubectl rollout resume deploy/nginx-test
deployment.extensions/nginx-test resumed
4.2.11 查看最后的更新情况
[root@master ~]# kubectl get pods -w
NAME                          READY   STATUS    RESTARTS   AGE
nginx-test-679dcbd68d-zw8w5   1/1     Running   0          61s
nginx-test-6cc7cd5547-4xqcb   1/1     Running   0          41m
nginx-test-6cc7cd5547-gcbh5   1/1     Running   0          41m
nginx-test-6cc7cd5547-nw6k6   1/1     Running   0          41m
nginx-test-6cc7cd5547-gcbh5   1/1     Terminating   0          63m
nginx-test-679dcbd68d-cljzh   0/1     Pending       0          0s
nginx-test-679dcbd68d-cljzh   0/1     Pending       0          0s
nginx-test-679dcbd68d-cljzh   0/1     ContainerCreating   0          0s
nginx-test-6cc7cd5547-gcbh5   0/1     Terminating         0          63m
nginx-test-6cc7cd5547-gcbh5   0/1     Terminating         0          63m
nginx-test-6cc7cd5547-gcbh5   0/1     Terminating         0          63m
nginx-test-679dcbd68d-cljzh   1/1     Running             0          1s
nginx-test-6cc7cd5547-nw6k6   1/1     Terminating         0          63m
nginx-test-679dcbd68d-s2gck   0/1     Pending             0          0s
nginx-test-679dcbd68d-s2gck   0/1     Pending             0          0s
nginx-test-679dcbd68d-s2gck   0/1     ContainerCreating   0          0s
nginx-test-679dcbd68d-s2gck   1/1     Running             0          1s
nginx-test-6cc7cd5547-4xqcb   1/1     Terminating         0          63m
nginx-test-6cc7cd5547-nw6k6   0/1     Terminating         0          63m
nginx-test-6cc7cd5547-4xqcb   0/1     Terminating         0          63m
nginx-test-6cc7cd5547-nw6k6   0/1     Terminating         0          63m
nginx-test-6cc7cd5547-nw6k6   0/1     Terminating         0          63m
nginx-test-6cc7cd5547-4xqcb   0/1     Terminating         0          63m
nginx-test-6cc7cd5547-4xqcb   0/1     Terminating         0          63m

二、声明式管理

1. 声明式管理方法

  1. 适合于对资源的修改操作
  2. 声明式资源管理方法依赖于资源配置清明文件对资源进行管理
    资源配置清单文件有两种格式:yaml(人性化,易读),json(易于api接口解析)
  3. 对资源的观念里,是通过实现定义在同一资源配置清单内,再通过陈述式命令应用到k8s集群里
  4. 语法格式:kubectl create/apply/delete -f -o yaml

2. 查看资源配置清单

kubectl get deploy/nginx-test -o yaml

[root@master ~]# kubectl get deploy/nginx-test -o yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "3"
    kubernetes.io/change-cause: nginx1.14
  creationTimestamp: "2021-11-03T11:47:56Z"
  generation: 7
  labels:
    run: nginx-test
  name: nginx-test
  namespace: default
  resourceVersion: "105895"
  selfLink: /apis/extensions/v1beta1/namespaces/default/deployments/nginx-test
  uid: 634d471e-3907-4717-a02e-f5cce101d2f4
spec:
  progressDeadlineSeconds: 600
  replicas: 3
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      run: nginx-test
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        run: nginx-test
    spec:
      containers:
      - image: nginx:1.14
        imagePullPolicy: IfNotPresent
        name: nginx-test
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status:
  availableReplicas: 3
  conditions:
  - lastTransitionTime: "2021-11-03T11:47:58Z"
    lastUpdateTime: "2021-11-03T11:47:58Z"
    message: Deployment has minimum availability.
    reason: MinimumReplicasAvailable
    status: "True"
    type: Available
  - lastTransitionTime: "2021-11-03T12:50:56Z"
    lastUpdateTime: "2021-11-03T12:57:35Z"
    message: ReplicaSet "nginx-test-6cc7cd5547" has successfully progressed.
    reason: NewReplicaSetAvailable
    status: "True"
    type: Progressing
  observedGeneration: 7
  readyReplicas: 3
  replicas: 3
  updatedReplicas: 3

kubectl get service nginx-service -o yaml

[root@master ~]# kubectl get service nginx-service -o yaml
apiVersion: v1
kind: Service
metadata:
  creationTimestamp: "2021-11-03T11:52:40Z"
  labels:
    run: nginx-test
  name: nginx-service
  namespace: default
  resourceVersion: "100051"
  selfLink: /api/v1/namespaces/default/services/nginx-service
  uid: b2ec9834-864a-4146-9296-5420ac15451d
spec:
  clusterIP: 10.1.36.134
  externalTrafficPolicy: Cluster
  ports:
  - nodePort: 30191
    port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx-test
  sessionAffinity: None
  type: NodePort
status:
  loadBalancer: {}

3. 解释资源配置清单

kubectl explain deployment.metadata

[root@master ~]# kubectl explain deployment.metadata
KIND:     Deployment
VERSION:  extensions/v1beta1

RESOURCE: metadata <Object>

DESCRIPTION:
     Standard object metadata.

     ObjectMeta is metadata that all persisted resources must have, which
     includes all objects users must create.

FIELDS:
   annotations	<map[string]string>
     Annotations is an unstructured key value map stored with a resource that
     may be set by external tools to store and retrieve arbitrary metadata. They
     are not queryable and should be preserved when modifying objects. More
     info: http://kubernetes.io/docs/user-guide/annotations
......

kubectl explain service.metadata

[root@master ~]# kubectl explain service.metadata
KIND:     Service
VERSION:  v1

RESOURCE: metadata <Object>

DESCRIPTION:
     Standard object's metadata. More info:
     https://git.k8s.io/community/contributors/devel/api-conventions.md#metadata

     ObjectMeta is metadata that all persisted resources must have, which
     includes all objects users must create.

FIELDS:
   annotations	<map[string]string>
     Annotations is an unstructured key value map stored with a resource that
     may be set by external tools to store and retrieve arbitrary metadata. They
     are not queryable and should be preserved when modifying objects. More
     info: http://kubernetes.io/docs/user-guide/annotations
......

4. 修改资源配置清单并应用

4.1 离线修改

修改yaml文件:并用kubectl apply -f xxxx.yaml文件使之生效
注意:当apply不生效时,先使用delete清除资源,再apply创建资源
kubectl get service nginx-service -o yaml > nginx-svc.yaml

[root@master ~]# kubectl get service nginx-service -o yaml > nginx-svc.yaml
[root@master ~]# vim nginx-svc.yaml 

apiVersion: v1
kind: Service
metadata:
  creationTimestamp: "2021-11-03T11:52:40Z"
  labels:
    run: nginx-test
  name: nginx-service
  namespace: default
  resourceVersion: "100051"
  selfLink: /api/v1/namespaces/default/services/nginx-service
  uid: b2ec9834-864a-4146-9296-5420ac15451d
spec:
  clusterIP: 10.1.36.134
  externalTrafficPolicy: Cluster
  ports:
  - nodePort: 30191
#修改port为80
    port: 8080
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx-test
  sessionAffinity: None
  type: NodePort
status:
  loadBalancer: {}

删除资源
kubectl delete -f nginx-svc.yaml

[root@master ~]# kubectl delete -f nginx-svc.yaml
service "nginx-service" deleted

新建资源
kubectl apply -f nginx-svc.yaml

[root@master ~]# kubectl apply -f nginx-svc.yaml
service/nginx-service created

查看service资源
kubectl get svc

[root@master ~]# kubectl get svc
NAME            TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)          AGE
kubernetes      ClusterIP   10.1.0.1      <none>        443/TCP          25h
nginx-service   NodePort    10.1.36.134   <none>        8080:30191/TCP   56s

4.2 在线修改

直接使用kubectl edit service nginx-service在线编辑配置资源清单并保存退出即时生效(如port: 888)
PS:此修改方式不会对yaml文件内容修改
kubectl edit service nginx-service

[root@master ~]# kubectl edit service nginx-service
 
......
  ports:
  - nodePort: 30191
#修改port为888
    port: 888
    protocol: TCP
    targetPort: 80
......

查看service资源
kubectl get svc

[root@master ~]# kubectl get svc
NAME            TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)         AGE
kubernetes      ClusterIP   10.1.0.1      <none>        443/TCP         25h
nginx-service   NodePort    10.1.36.134   <none>        888:30191/TCP   6m50s

5. 删除资源配置清单

5.1 陈述式删除

kubectl delete service nginx-service

[root@master ~]# kubectl delete service nginx-service
service "nginx-service" deleted
[root@master ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.1.0.1     <none>        443/TCP   25h

5.2 声明式删除

kubectl delete -f nginx-svc.yaml

[root@master ~]# kubectl apply -f nginx-svc.yaml 
service/nginx-service created
[root@master ~]# kubectl get svc
NAME            TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)          AGE
kubernetes      ClusterIP   10.1.0.1      <none>        443/TCP          25h
nginx-service   NodePort    10.1.36.134   <none>        8080:30191/TCP   1s
[root@master ~]# kubectl delete -f nginx-svc.yaml 
service "nginx-service" deleted
[root@master ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.1.0.1     <none>        443/TCP   25h

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