Kubernetes滚动更新及回滚

 # 和rs一模一样。但是不支持复杂的matchLabel机制
 [root@yygh-de rollback]# kubectl explain rc.spec
 KIND:     ReplicationController
 VERSION: v1
 
 RESOURCE: spec <Object>
 
 DESCRIPTION:
     Spec defines the specification of the desired behavior of the replication
     controller. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
 
     ReplicationControllerSpec is the specification of a replication controller.
 
 FIELDS:
   minReadySeconds<integer>
     Minimum number of seconds forwhich a newly created pod should be ready
     without any of its container crashing, forit to be considered available.
     Defaults to 0(pod will be considered available as soon as it is ready)
 
   replicas<integer>
     Replicas is the number of desired replicas. This is a pointer to
     distinguish between explicit zero and unspecified. Defaults to 1. More
     info:
     https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller#what-is-a-replicationcontroller
 
   selector<map[string]string>
     Selector is a label query over pods that should match the Replicas count.
     If Selector is empty, it is defaulted to the labels present on the Pod
     template. Label keys and values that must match inorder to be controlled
     by this replication controller, ifempty defaulted to labels on Pod
     template. More info:
     https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors
 
   template<Object>
     Template is the object that describes the pod that will be created if
     insufficient replicas are detected. This takes precedence over a
     TemplateRef. More info:
     https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller#pod-template

 [root@yygh-de rollback]# kubectl explain rs.spec
 KIND:     ReplicaSet
 VERSION: apps/v1
 
 RESOURCE: spec <Object>
 
 DESCRIPTION:
     Spec defines the specification of the desired behavior of the ReplicaSet.
     More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
 
     ReplicaSetSpec is the specification of a ReplicaSet.
 
 FIELDS:
   minReadySeconds<integer>
     Minimum number of seconds forwhich a newly created pod should be ready
     without any of its container crashing, forit to be considered available.
     Defaults to 0(pod will be considered available as soon as it is ready)
 # Kubernetes在等待设置的时间后才进行升级
 # 如果没有设置该值，Kubernetes会假设该容器启动起来后就提供服务了
 # 如果没有设置该值，在某些极端情况下可能会造成服务服务正常运行
   replicas<integer>
     Replicas is the number of desired replicas. This is a pointer to
     distinguish between explicit zero and unspecified. Defaults to 1. More
     info:
 # 保证的副本数     https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller/#what-is-a-replicationcontroller
 
   selector<Object> -required-
     Selector is a label query over pods that should match the replica count.
     Label keys and values that must match inorder to be controlled by this
     replica set. It must match the pod template's labels. More info:
     https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors
 
   template<Object>
     Template is the object that describes the pod that will be created if
     insufficient replicas are detected. More info:
     https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller#pod-template

 [root@yygh-de rollback]# kubectl explain deploy.spec
 KIND:     Deployment
 VERSION: apps/v1
 
 RESOURCE: spec <Object>
 
 DESCRIPTION:
     Specification of the desired behavior of the Deployment.
 
     DeploymentSpec is the specification of the desired behavior of the
     Deployment.
 
 FIELDS:
   minReadySeconds<integer>
     Minimum number of seconds forwhich a newly created pod should be ready
     without any of its container crashing, forit to be considered available.
     Defaults to 0(pod will be considered available as soon as it is ready)
 
   paused<boolean>
     Indicates that the deployment is paused.
 # 用于暂停记录部署版本信息
   progressDeadlineSeconds<integer>
     The maximum time inseconds fora deployment to makeprogress before it is
     considered to be failed. The deployment controller will continue to process
     failed deployments and a condition with a ProgressDeadlineExceeded reason
     will be surfaced inthe deployment status. Note that progress will not be
     estimated during the time a deployment is paused. Defaults to 600s.
 # 等待多少秒才能确定Deployment进程是卡住的。如果卡住，这次部署失败，并汇报自己状态，我们可以用kubectl describe查看原因，进行手动修复等
   replicas<integer>
     Number of desired pods. This is a pointer to distinguish between explicit
     zero and not specified. Defaults to 1.
 # 副本
   revisionHistoryLimit<integer>
     The number of old ReplicaSets to retain to allow rollback. This is a
     pointer to distinguish between explicit zero and not specified. Defaults to
     10.
 # 历史总记录数
   selector<Object> -required-
     Label selector forpods. Existing ReplicaSets whose pods are selected by
     this will be the ones affected by this deployment. It must match the pod
     template's labels.
 
   strategy<Object>
     The deployment strategy to use to replace existing pods with new ones.
 # 滚动更新策略
   template<Object> -required-
     Template describes the pods that will be created.

 [root@yygh-de rollback]# kubectl explain deploy.spec.strategy
 KIND:     Deployment
 VERSION: apps/v1
 
 RESOURCE: strategy <Object>
 
 DESCRIPTION:
     The deployment strategy to use to replace existing pods with new ones.
 
     DeploymentStrategy describes how to replace existing pods with new ones.
 
 FIELDS:
   rollingUpdate<Object>
     Rolling update config params. Present only ifDeploymentStrategyType =
     RollingUpdate.
 #     Recreate 全部重新创建
 #     RollingUpdate 拉起一个停一个
   type<string>
     Type of deployment. Can be "Recreate"or "RollingUpdate". Default is
     RollingUpdate.

 [root@yygh-de rollback]# kubectl explain deploy.spec.strategy.rollingUpdate
 KIND:     Deployment
 VERSION: apps/v1
 
 RESOURCE: rollingUpdate <Object>
 
 DESCRIPTION:
     Rolling update config params. Present only ifDeploymentStrategyType =
     RollingUpdate.
 
     Spec to control the desired behavior of rolling update.
 
 FIELDS:
   maxSurge<string>
     The maximum number of pods that can be scheduled above the desired number
     of pods. Value can be an absolute number (ex: 5) or a percentage of desired
     pods (ex: 10%). This can not be 0ifMaxUnavailable is 0. Absolute number
     is calculated from percentage by rounding up. Defaults to 25%. Example:
     when this is setto 30%, the new ReplicaSet can be scaled up immediately
     when the rolling update starts, such that the total number of old and new
     pods donot exceed 130% of desired pods. Once old pods have been killed,
     new ReplicaSet can be scaled up further, ensuring that total number of pods
     running at any time during the update is at most 130% of desired pods.
 
   maxUnavailable<string>
     The maximum number of pods that can be unavailable during the update. Value
     can be an absolute number (ex: 5) or a percentage of desired pods (ex:
     10%). Absolute number is calculated from percentage by rounding down. This
     can not be 0ifMaxSurge is 0. Defaults to 25%. Example: when this is set
     to 30%, the old ReplicaSet can be scaled down to 70% of desired pods
     immediately when the rolling update starts. Once new pods are ready, old
     ReplicaSet can be scaled down further, followed by scaling up the new
     ReplicaSet, ensuring that the total number of pods available at all times
     during the update is at least 70% of desired pods.

 [root@yygh-de rollback]# vim test.yaml
 apiVersion: apps/v1
 kind: Deployment
 metadata:
 name: frontend-test
 labels:
   app: guestbook
   tier: frontend
 spec:
  # modify replicas according to your case
 strategy:
   rollingUpdate:
     maxSurge: 1
     maxUnavailable: 2
 replicas: 6
 selector:
   matchLabels:
     tier: frontend-test
 template:
   metadata:
     labels:
       tier: frontend-test
   spec:
     containers:
      -name: php-redis
       image: tomcat:6

 [root@yygh-de rollback]# kubectl apply -f test.yaml 
 deployment.apps/frontend-test created
 [root@yygh-de rollback]# kubectl set image deployment.apps/frontend-test php-redis=tomcat:777
 [root@yygh-de rollback]# kubectl get pod
 NAME                             READY   STATUS             RESTARTS   AGE
 frontend-test-6f8656f964-8lt6p   0/1     ImagePullBackOff   0        25s
 frontend-test-6f8656f964-j2d7s   0/1     ImagePullBackOff   0        25s
 frontend-test-6f8656f964-jcx6p   0/1     ImagePullBackOff   0        25s
 frontend-test-c986f4d7c-5qjqt    1/1     Running            0        48s
 frontend-test-c986f4d7c-7wgjz    1/1     Running            0        48s
 frontend-test-c986f4d7c-lbl6l    1/1     Running            0        48s
 frontend-test-c986f4d7c-nxr7r    1/1     Running            0        48s
 [root@yygh-de rollback]# kubectl get deployment
 NAME           READY   UP-TO-DATE   AVAILABLE   AGE
 frontend-test   4/6     3           4          43s

 [root@yygh-de rollback]# vim abcdocker-test.yaml
 apiVersion: apps/v1
 kind: Deployment
 metadata:
 name: nginx-deployment
 spec:
 replicas: 6
 selector:
   matchLabels:
     app: nginx
 template:
   metadata:
     labels:
       app: nginx
   spec:
     containers:
      -name: nginx
       image: nginx:1.13.0-alpine
       imagePullPolicy: IfNotPresent
       ports:
        -containerPort: 80

 [root@yygh-de rollback]# kubectl apply -f abcdocker-test.yaml --record

 [root@yygh-de rollback]# kubectl get pod
 NAME                               READY   STATUS   RESTARTS   AGE
 nginx-deployment-7dbcbc677f-2f2dd   1/1     Running   0        5s
 nginx-deployment-7dbcbc677f-8hw96   1/1     Running   0        5s
 nginx-deployment-7dbcbc677f-lvlqr   1/1     Running   0        5s
 nginx-deployment-7dbcbc677f-ntjqh   1/1     Running   0        5s
 nginx-deployment-7dbcbc677f-qfgn6   1/1     Running   0        5s
 nginx-deployment-7dbcbc677f-zqbpz   1/1     Running   0        5s

 [root@yygh-de rollback]# sed -i 's#1.13.0-alpine#1.10.0-alpine#g' abcdocker-test.yaml
 [root@yygh-de rollback]# kubectl apply -f abcdocker-test.yaml --record
 deployment.apps/nginx-deployment configured
 # --record的作用是将当前命令记录到 revision 记录中，这样我们就可以知道每个 revison 对应的是哪个配置文件。

 ^C[root@yygh-de rollback]# kubectl get deployment
 NAME               READY   UP-TO-DATE   AVAILABLE   AGE
 nginx-deployment   6/6     6           6          6m42s
 [root@yygh-de rollback]# kubectl edit deployments nginx-deployment

 [root@yygh-de rollback]# kubectl set image deploy nginx-deployment nginx=nginx.13.0-alpine

 [root@yygh-de rollback]# kubectl rollout status deployment/nginx-deployment
 deployment "nginx-deployment"successfully rolled out

 [root@yygh-de rollback]# kubectl rollout pause deployment deployment/nginx-deployment

 [root@yygh-de rollback]# kubectl rollout resume deployment deployment/nginx-deployment

 [root@yygh-de rollback]# kubectl get rs
 # 根据AGE我们可以看到离我们最近的当前状态是：3，和我们的yaml文件是一致的，证明升级成功了。用describe命令可以查看升级的全部信息.

 [root@yygh-de rollback]# kubectl rollout history deployment nginx-deployment
 deployment.apps/nginx-deployment 
 REVISION CHANGE-CAUSE
 2        kubectl apply --filename=abcdocker-test.yaml --record=true
 4        kubectl apply --filename=abcdocker-test.yaml --record=true
 5        kubectl apply --filename=abcdocker-test.yaml --record=true

 [root@yygh-de rollback]# kubectl rollout history deployment nginx-deployment --revision=4
 deployment.apps/nginx-deployment with revision #4
 Pod Template:
 Labels:app=nginx
 pod-template-hash=678746dbb4
 Annotations:kubernetes.io/change-cause: kubectl apply --filename=abcdocker-test.yaml --record=true
 Containers:
   nginx:
   Image:nginx:1.10.0-alpine
   Port:80/TCP
   Host Port:0/TCP
   Environment:<none>
   Mounts:<none>
 Volumes:<none>

 [root@yygh-de rollback]# kubectl rollout undo deployment nginx-deployment

 [root@yygh-de rollback]# kubectl rollout undo deployment nginx-deployment --to-revision=5