K8S之资源控制器RC、RS、Deployment详解

爱被打了一巴掌 2022-12-23 14:23 219阅读 0赞

### K8S之资源控制器RC、RS、Deployment详解 ###

*   *  1. （Controller）-Deployment
     *   *  1.1. 介绍
         *   *  1. 简介
             *  2. 部署方式
             *  3. Deployment升级方案
         *  1.2. 模板
         *  1.3 Pod和Controller关系
 *  2、Deployment控制器应用场景
 *   *  2.1 yaml文件字段说明
     *  2.2 Deployment控制器应用部署
     *  2.3 ReplicaSet示例
     *  2.4 Deployment示例
     *   *  创建 Deployment
         *  刚启动时状态说明
     *  2.5 更新 Deployment
     *  2.6 多 Deployment 动态更新
     *   *  回滚 Deployment
         *  yaml文件方式
         *  命令行方式
     *  2.7 扩容/缩容Deployment
     *  2.8 清理策略Policy
 *  3、 升级回滚
 *  3、 弹性伸缩
 *  案例
 *   *   *   *  1. 创建deployment
             *  2. 模拟蓝绿发布
             *  3. 滚动发布
             *  4. 模拟灰度(金丝雀)发布
             *  5. 版本回滚
             *  6. 常用命令

## 1. （Controller）-Deployment ##

### 1.1. 介绍 ###

kubernetes中内建了很多controller（控制器），这些相当于一个状态机，用来控制pod的具体状态和行为。

Controller，在集群上管理和运行容器的对象。

*  确保预期的Pod副本数量
 *  无状态应用部署
 *  有状态应用部署
 *  确保所有的node运行同一个pod
 *  一次性任务和定时任务

**部分控制器类型如下：**

*  ReplicationController 和 ReplicaSet
 *  Deployment
 *  DaemonSet
 *  StatefulSet
 *  Job/CronJob
 *  HorizontalPodAutoscaler

#### 1. 简介 ####

Pod控制器有很多种，最初的是使用 ReplicationController，即副本控制器，用于控制pod数量。随着版本升级，出现了ReplicaSet，跟ReplicationController没有本质的不同，只是名字不一样，并且ReplicaSet支持集合式的selector。ReplicaSet的核心管理对象有三种：用户期望的副本数、标签选择器、pod模板。

ReplicaSet一般不会直接使用，而是采用Deployment，Deployment是用来管理Replicaset，ReplicaSet来管理Pod。Deployment为ReplicaSet 提供了一个声明式定义(declarative)方法，用来替代以前的 ReplicationController 来方便的管理应用，比ReplicaSet的功能更加强大，且包含了ReplicaSet的功能。Deployment支持以下功能：

*  定义Deployment来创建Pod和ReplicaSet
 *  滚动升级和回滚应用
 *  扩容和缩容
 *  暂停部署功能和手动部署

#### 2. 部署方式 ####

*  蓝绿发布

如图，假设副本数是5，目标是从v1升级到v2。先部署5个v2版本的业务机器，再将SLB的流量全部切换到v2上。如果出现异常，可以快速切换到v1版本。但是实际上用的不多，因为需要消耗大量的额外机器资源。

![image.png][]

*  滚动发布

滚动发布是逐台(批次)升级，需要占用的额外资源少。比如先升级一台，再升级一台，直到全部升级完毕。也可以每次升级10%数量的机器，逐批次升级。

![image.png][image.png 1]

*  灰度发布(金丝雀发布)

灰度发布也叫金丝雀发布，起源是，矿井工人发现，金丝雀对瓦斯气体很敏感，矿工会在下井之前，先放一只金丝雀到井中，如果金丝雀不叫了，就代表瓦斯浓度高。

灰度发布会先升级一台灰度机器，将版本升级为v2，此时先经过测试验证，确认没有问题后。从LB引入少量流量进入灰度机器，运行一段时间后，再将其它机器升级为v2版本，引入全部流量。

![image.png][image.png 2]

#### 3. Deployment升级方案 ####

Deployment的升级方案默认是滚动升级，支持升级暂停，支持指定最大超过预期pod数量，支持指定最小低于预期pod数量。可以实现上述三种部署方案(以目标预期pod数量5个，v1版本升级到v2版本为案例)：

*  蓝绿发布场景实现方案：新创建5个v2版本pod，等待5个v2版本Pod就绪后，下掉5个v1版本pod。
 *  灰度发布场景实现案例：新创建的第一个pod最为灰度pod，此时暂定升级，等待灰度成功后再升级v1版本Pod
 *  滚动发布：通过控制超出预期pod数量和低于预期Pod数量来控制滚动发布的节奏。

如下图，预期pod数量5个，滚动升级，最大超出副本数为2个，最大低于期望值2个的升级方式：

![image.png][image.png 3]

### 1.2. 模板 ###

apiVersion: apps/v1
    kind: Deployment
    metadata
        name        <string>                            # 在一个名称空间不能重复
        namespace   <string>                            # 指定名称空间，默认defalut
        labels      <map[string]string>                 # 标签
        annotations <map[string]string>                 # 注释
    
    spec
        replicas                    <integer>           # 期望副本数，默认值1
        selector                    <Object>            # 标签选择器
            matchExpressions        <[]Object>          # 标签选择器的一种形式,多个条件使用AND连接
                key                 <string> -required- # 标签中的Key
                operator            <string> -required- # 操作符，支持 In, NotIn, Exists, DoesNotExist
                values              <[]string>          # value的数组集合，当操作符为In或NotIn时不能为空
            matchLabels             <map[string]string> # 使用key/value的格式做筛选
        strategy                    <Object>            # pod更新策略，即如何替换已有的pod
            type                    <string>            # 更新类型，支持 Recreate, RollingUpdate。默认RollingUpdate
            rollingUpdate           <Object>            # 滚动更新策略，仅在type为RollingUpdate时使用
                maxSurge            <string>            # 最大浪涌pod数，即滚动更新时最多可多于出期望值几个pod。支持数字和百分比格式
                maxUnavailable      <string>            # 最大缺失Pod数，即滚动更新时最多可少于期望值出几个pod。支持数字和百分比格式
        revisionHistoryLimit        <integer>           # 历史版本记录数，默认为最大值(2^32)
        template                    <Object> -required- # Pod模板，和Pod管理器yaml几乎格式一致
            metadata                <Object>            # Pod的metadata
            spec                    <Object>            # Pod的spec

### 1.3 Pod和Controller关系 ###

*  Pod是通过Controller实现应用的运维，比如伸缩，滚动升级等。
 *  Pod和Controller之间通过label标签建立关系

# 2、Deployment控制器应用场景 #

Deployment 控制器为 Pods和 ReplicaSets提供描述性的更新方式。用来替代以前的ReplicationController以方便管理应用。

**典型的应用场景包括：**

*  定义Deployment来创建Pod和ReplicaSet
 *  滚动升级和回滚应用
 *  扩容和缩容，管理Pod和ReplicaSet（副本数量）
 *  暂停和继续Deployment
 *  部署无状态应用（Web，微服务，nginx等）

## 2.1 yaml文件字段说明 ##

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## 2.2 Deployment控制器应用部署 ##

# 1.生成yaml文件到Web.yaml，导出yaml文件
    kubectl create deployment web --image=nginx --dry-run -o yaml > web.yaml

部署：

# 2.使用yaml部署应用
    kubectl apply -f web.yaml
    # 3.查看
    kubectl get pods
    # 4.对外发布（暴露对外端口号）-----先生成yaml文件
    kubectl expose deployment web --port=80 --type=NodePort --target-port=80 --name=web1 -o yaml >
    web1.yaml
    # 5. 使用yaml方式发布
    kubectl apply -f web1.yaml
    # 6、查看已经发布的应用
    kubectl get pods,svc

## 2.3 ReplicaSet示例 ##

yaml文件

[root@k8s-master controller]# pwd
    /root/k8s_practice/controller
    [root@k8s-master controller]# cat ReplicaSet-01.yaml
    apiVersion: apps/v1
    kind: ReplicaSet
    metadata:
      name: frontend
    spec:
      replicas: 3
      selector:
        matchLabels:
          tier: frontend
      template:
        metadata:
          labels:
            tier: frontend
        spec:
          containers:
          - name: nginx
            image: registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17
            imagePullPolicy: IfNotPresent
            ports:
            - name: httpd
              containerPort: 80

创建ReplicaSet，并查看rs状态与详情

[root@k8s-master controller]# kubectl apply -f ReplicaSet-01.yaml
    replicaset.apps/frontend created
    [root@k8s-master controller]# kubectl get rs -o wide # 查看状态
    NAME       DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES                                                        SELECTOR
    frontend   3         3         3       2m12s   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17   tier=frontend
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl describe rs frontend # 查看详情
    Name:         frontend
    Namespace:    default
    Selector:     tier=frontend
    Labels:       <none>
    Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                    { "apiVersion":"apps/v1","kind":"ReplicaSet","metadata":{ "annotations":{ },"name":"frontend","namespace":"default"},"spec":{ "replicas":3,"se...
    Replicas:     3 current / 3 desired
    Pods Status:  3 Running / 0 Waiting / 0 Succeeded / 0 Failed
    Pod Template:
      Labels:  tier=frontend
      Containers:
       nginx:
        Image:        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17
        Port:         80/TCP
        Host Port:    0/TCP
        Environment:  <none>
        Mounts:       <none>
      Volumes:        <none>
    Events:
      Type    Reason            Age    From                   Message
      ----    ------            ----   ----                   -------
      Normal  SuccessfulCreate  10m    replicaset-controller  Created pod: frontend-kltwp
      Normal  SuccessfulCreate  10m    replicaset-controller  Created pod: frontend-76dbn
      Normal  SuccessfulCreate  10m    replicaset-controller  Created pod: frontend-jk8td

查看pod状态信息

[root@k8s-master controller]# kubectl get pod -o wide --show-labels
    NAME             READY   STATUS    RESTARTS   AGE     IP            NODE         NOMINATED NODE   READINESS GATES   LABELS
    frontend-76dbn   1/1     Running   0          5m15s   10.244.4.31   k8s-node01   <none>           <none>            tier=frontend
    frontend-jk8td   1/1     Running   0          5m15s   10.244.2.35   k8s-node02   <none>           <none>            tier=frontend
    frontend-kltwp   1/1     Running   0          5m15s   10.244.2.34   k8s-node02   <none>           <none>            tier=frontend

删除一个pod，然后再次查看

[root@k8s-master controller]# kubectl delete pod frontend-kltwp
    pod "frontend-kltwp" deleted
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get pod -o wide --show-labels # 可见重新创建了一个pod
    NAME             READY   STATUS    RESTARTS   AGE     IP            NODE         NOMINATED NODE   READINESS GATES   LABELS
    frontend-76dbn   1/1     Running   0          7m27s   10.244.4.31   k8s-node01   <none>           <none>            tier=frontend
    frontend-jk8td   1/1     Running   0          7m27s   10.244.2.35   k8s-node02   <none>           <none>            tier=frontend
    frontend-mf79k   1/1     Running   0          16s     10.244.4.32   k8s-node01   <none>           <none>            tier=frontend

由上可见，rs又新建了一个pod，保证了pod数总是为3.

## 2.4 Deployment示例 ##

### 创建 Deployment ###

yaml文件

[root@k8s-master controller]# pwd
    /root/k8s_practice/controller
    [root@k8s-master controller]# cat nginx-deployment-1.17.1.yaml
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx-deployment
      labels:
        app: nginx
    spec:
      replicas: 3
      # 重点关注该字段
      selector:
        matchLabels:
          app: nginx
      template:
        metadata:
          labels:
            app: nginx
        spec:
          containers:
          - name: nginx
            image: registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.1
            ports:
            - containerPort: 80
    [root@k8s-master controller]#
    [root@k8s-master controller]# cat nginx-deployment-1.17.5.yaml
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx-deployment
      labels:
        app: nginx
    spec:
      replicas: 3
      # 重点关注该字段
      selector:
        matchLabels:
          app: nginx
      template:
        metadata:
          labels:
            app: nginx
        spec:
          containers:
          - name: nginx
            image: registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5
            ports:
            - containerPort: 80

selector 字段定义 Deployment 如何查找要管理的 Pods。 在这种情况下，会选择在 template（Pod）模板中定义的标签labels（app: nginx）。但更复杂的选择规则是可能的，只要 template （Pod） 模板本身满足规则。

### 刚启动时状态说明 ###

启动deployment，并查看状态

[root@k8s-master controller]# kubectl apply -f nginx-deployment-1.17.1.yaml --record
    deployment.apps/nginx-deployment created
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get deployment -o wide
    NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                          SELECTOR
    nginx-deployment   2/3     3            2           10s   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.1   app=nginx
    
    # --record 参数可以记录命令，通过 kubectl rollout history deployment/nginx-deployment 可查询

**参数说明：**

*  NAME：列出集群中 Deployments 的名称
 *  READY：已就绪副本数/期望副本数
 *  UP-TO-DATE：显示已更新和正在更新中的副本数
 *  AVAILABLE：显示应用程序可供用户使用的副本数
 *  AGE：显示运行的时间

查看ReplicaSet状态

[root@k8s-master controller]# kubectl get rs -o wide
    NAME                          DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                          SELECTOR
    nginx-deployment-76b9d6bcf5   3         3         2       17s   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.1   app=nginx,pod-template-hash=76b9d6bcf5

**参数说明：**

*  NAME：列出集群中 ReplicaSet的名称
 *  DESIRED：期望副本数
 *  CURRENT：当前副本数
 *  READY：已就绪副本数
 *  AGE：运行时间

查看pod状态

[root@k8s-master controller]# kubectl get pod -o wide
    NAME                                READY   STATUS              RESTARTS   AGE   IP            NODE         NOMINATED NODE   READINESS GATES
    nginx-deployment-76b9d6bcf5-ngpg5   1/1     Running             0          26s   10.244.2.43   k8s-node02   <none>           <none>
    nginx-deployment-76b9d6bcf5-rw827   1/1     Running             0          26s   10.244.2.44   k8s-node02   <none>           <none>
    nginx-deployment-76b9d6bcf5-ttf4j   0/1     ContainerCreating   0          26s   <none>        k8s-node01   <none>           <none>

过一会儿状态说明

[root@k8s-master controller]# kubectl get deployment -o wide --show-labels
    NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                          SELECTOR    LABELS
    nginx-deployment   3/3     3            3           23m   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.1   app=nginx   app=nginx
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get rs -o wide --show-labels
    NAME                          DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                          SELECTOR                                 LABELS
    nginx-deployment-76b9d6bcf5   3         3         3       23m   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.1   app=nginx,pod-template-hash=76b9d6bcf5   app=nginx,pod-template-hash=76b9d6bcf5
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get pod -o wide --show-labels
    NAME                                READY   STATUS    RESTARTS   AGE   IP            NODE         NOMINATED NODE   READINESS GATES   LABELS
    nginx-deployment-76b9d6bcf5-ngpg5   1/1     Running   0          23m   10.244.2.43   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=76b9d6bcf5
    nginx-deployment-76b9d6bcf5-rw827   1/1     Running   0          23m   10.244.2.44   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=76b9d6bcf5
    nginx-deployment-76b9d6bcf5-ttf4j   1/1     Running   0          23m   10.244.4.37   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=76b9d6bcf5

**重点说明**

1、ReplicaSet 的名称始终被格式化为`[DEPLOYMENT-NAME]-[RANDOM-STRING]`。随机字符串是随机生成，并使用 pod-template-hash 作为选择器和标签。

2、Deployment 控制器将 pod-template-hash 标签添加到 Deployment 创建或使用的每个 ReplicaSet 。此标签可确保 Deployment 的子 ReplicaSets 不重叠。因此不可修改。

3、注意Deployment、ReplicaSet和Pod三者的名称关系

## 2.5 更新 Deployment ##

Deployment 可确保在更新时仅关闭一定数量的 Pods。默认情况下，它确保至少 75%所需 Pods 运行（25%最大不可用）。

Deployment 更新过程中还确保仅创建一定数量的 Pods 且高于期望的 Pods 数。默认情况下，它可确保最多增加 25% 期望 Pods 数（25%最大增量）。

备注：实际操作中如果更新Deployment，那么最好通过yaml文件更新，这样回滚到任何版本都非常便捷，而且更容易追述；而不是通过命令行。

如下Deployment示例，由于只有3个副本。因此更新时不会先删除旧的pod，而是先新建一个pod。新pod运行时，才会删除对应老的pod。一切的前提都是为了满足上述的条件。

需求：更新 nginx Pods，从当前的1.17.1版本改为1.17.5版本。

# 方式一
    kubectl edit deployment/nginx-deployment    # 然后修改 image 镜像信息 【不推荐】
    # 上述方法不会记录命令，通过kubectl rollout history deployment/nginx-deployment 无法查询
    
    # 方式二如下【可使用】：
    kubectl set image deployment/nginx-deployment nginx=registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5 --record
    
    # 方式三如下【推荐★★★★★】
    kubectl apply -f nginx-deployment-1.17.5.yaml --record
    
    # --record 参数可以记录命令，通过 kubectl rollout history deployment/nginx-deployment 可查询

要查看更新状态

[root@k8s-master controller]# kubectl rollout status deployment/nginx-deployment
    # 如没有更新完成，则显示更新过程直到更新成功
    Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 3 new replicas have been updated...
    Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 3 new replicas have been updated...
    Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
    Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
    Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
    Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
    deployment "nginx-deployment" successfully rolled out
    # 如已更新完毕，直接显示更新成功
    deployment "nginx-deployment" successfully rolled out

**更新中的Deployment、ReplicaSet、Pod信息**

[root@k8s-master controller]# kubectl get deployment -o wide --show-labels
    NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                          SELECTOR    LABELS
    nginx-deployment   3/3     1            3           12m   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5   app=nginx   app=nginx
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get rs -o wide --show-labels
    NAME                          DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                          SELECTOR                                 LABELS
    nginx-deployment-56d78686f5   1         1         0       23s   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5   app=nginx,pod-template-hash=56d78686f5   app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-76b9d6bcf5   3         3         3       12m   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.1   app=nginx,pod-template-hash=76b9d6bcf5   app=nginx,pod-template-hash=76b9d6bcf5
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get pod -o wide --show-labels
    NAME                                READY   STATUS              RESTARTS   AGE   IP            NODE         NOMINATED NODE   READINESS GATES   LABELS
    nginx-deployment-56d78686f5-4kn4c   0/1     ContainerCreating   0          30s   <none>        k8s-node02   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-76b9d6bcf5-7lcr9   1/1     Running             0          12m   10.244.4.41   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=76b9d6bcf5
    nginx-deployment-76b9d6bcf5-jbb5h   1/1     Running             0          12m   10.244.2.48   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=76b9d6bcf5
    nginx-deployment-76b9d6bcf5-rt4m7   1/1     Running             0          12m   10.244.4.42   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=76b9d6bcf5

**更新成功后的Deployment、ReplicaSet、Pod信息**

[root@k8s-master controller]# kubectl get deployment -o wide --show-labels
    NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                          SELECTOR    LABELS
    nginx-deployment   3/3     3            3           15m   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5   app=nginx   app=nginx
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get rs -o wide --show-labels
    NAME                          DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES                                                          SELECTOR                                 LABELS
    nginx-deployment-56d78686f5   3         3         3       3m23s   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5   app=nginx,pod-template-hash=56d78686f5   app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-76b9d6bcf5   0         0         0       15m     nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.1   app=nginx,pod-template-hash=76b9d6bcf5   app=nginx,pod-template-hash=76b9d6bcf5
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get pod -o wide --show-labels
    NAME                                READY   STATUS    RESTARTS   AGE     IP            NODE         NOMINATED NODE   READINESS GATES   LABELS
    nginx-deployment-56d78686f5-4kn4c   1/1     Running   0          3m25s   10.244.2.49   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-khsnm   1/1     Running   0          100s    10.244.2.50   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-t24qw   1/1     Running   0          2m44s   10.244.4.43   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=56d78686f5

通过查询Deployment详情，知晓pod替换过程

[root@k8s-master controller]# kubectl describe deploy nginx-deployment
    Name:                   nginx-deployment
    Namespace:              default
    CreationTimestamp:      Thu, 28 May 2020 00:04:09 +0800
    Labels:                 app=nginx
    Annotations:            deployment.kubernetes.io/revision: 2
                            kubectl.kubernetes.io/last-applied-configuration:
                              { "apiVersion":"apps/v1","kind":"Deployment","metadata":{ "annotations":{ "kubernetes.io/change-cause":"kubectl apply --filename=nginx-deploy...
                            kubernetes.io/change-cause:
                              kubectl set image deployment/nginx-deployment nginx=registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5 --record=true
    Selector:               app=nginx
    Replicas:               3 desired | 3 updated | 3 total | 3 available | 0 unavailable
    StrategyType:           RollingUpdate
    MinReadySeconds:        0
    RollingUpdateStrategy:  25% max unavailable, 25% max surge
    Pod Template:
      Labels:  app=nginx
      Containers:
       nginx:
        Image:        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5
        Port:         80/TCP
        Host Port:    0/TCP
        Environment:  <none>
        Mounts:       <none>
      Volumes:        <none>
    Conditions:
      Type           Status  Reason
      ----           ------  ------
      Available      True    MinimumReplicasAvailable
      Progressing    True    NewReplicaSetAvailable
    OldReplicaSets:  <none>
    NewReplicaSet:   nginx-deployment-56d78686f5 (3/3 replicas created)
    Events:
      Type    Reason             Age   From                   Message
      ----    ------             ----  ----                   -------
      Normal  ScalingReplicaSet  93s   deployment-controller  Scaled up replica set nginx-deployment-76b9d6bcf5 to 3
      Normal  ScalingReplicaSet  38s   deployment-controller  Scaled up replica set nginx-deployment-56d78686f5 to 1
      Normal  ScalingReplicaSet  37s   deployment-controller  Scaled down replica set nginx-deployment-76b9d6bcf5 to 2
      Normal  ScalingReplicaSet  37s   deployment-controller  Scaled up replica set nginx-deployment-56d78686f5 to 2
      Normal  ScalingReplicaSet  35s   deployment-controller  Scaled down replica set nginx-deployment-76b9d6bcf5 to 1
      Normal  ScalingReplicaSet  35s   deployment-controller  Scaled up replica set nginx-deployment-56d78686f5 to 3
      Normal  ScalingReplicaSet  34s   deployment-controller  Scaled down replica set nginx-deployment-76b9d6bcf5 to 0

## 2.6 多 Deployment 动态更新 ##

当 Deployment 正在展开进行更新时，Deployment 会为每个更新创建一个新的 ReplicaSet 并开始向上扩展，之前的 ReplicaSet 会被添加到旧 ReplicaSets 队列并开始向下扩展。

例如，假设创建一个 Deployment 以创建 nginx:1.7.9 的 5 个副本，然后更新 Deployment 以创建 5 个 nginx:1.9.1 的副本，而此时只有 3 个nginx:1.7.9 的副本已创建。在这种情况下， Deployment 会立即开始杀死3个 nginx:1.7.9 Pods，并开始创建 nginx:1.9.1 Pods。它不等待 nginx:1.7.9 的 5 个副本完成后再更新为nginx:1.9.1。

### 回滚 Deployment ###

### yaml文件方式 ###

针对应用的每个镜像版本，都有对应deploy的yaml文件。不管是升级还是回滚都已轻松应对。如下

nginx-deployment-1.15.6.yaml
    nginx-deployment-1.17.yaml
    nginx-deployment-1.17.1.yaml
    nginx-deployment-1.17.5.yaml

yaml文件中的信息，参考上文即可。

### 命令行方式 ###

**问题产生**

假设在更新 Deployment 时犯了一个拼写错误，将镜像名称命名为了 nginx:1.1710 而不是 nginx:1.17.10

[root@k8s-master controller]# kubectl set image deployment/nginx-deployment nginx=registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.1710 --record
    deployment.apps/nginx-deployment image updated

查看Deployment、ReplicaSet、Pod信息

[root@k8s-master controller]# kubectl get deploy -o wide --show-labels
    NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                          SELECTOR    LABELS
    nginx-deployment   3/3     1            3           14m   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.1710   app=nginx   app=nginx
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get rs -o wide --show-labels
    NAME                          DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES                                                          SELECTOR                                 LABELS
    nginx-deployment-55c7bdfb86   3         3         3       9m19s   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17     app=nginx,pod-template-hash=55c7bdfb86   app=nginx,pod-template-hash=55c7bdfb86
    nginx-deployment-56d78686f5   0         0         0       12m     nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5   app=nginx,pod-template-hash=56d78686f5   app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-76b9d6bcf5   0         0         0       13m     nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.1   app=nginx,pod-template-hash=76b9d6bcf5   app=nginx,pod-template-hash=76b9d6bcf5
    nginx-deployment-844d7bbb7f   1         1         0       64s     nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.1710   app=nginx,pod-template-hash=844d7bbb7f   app=nginx,pod-template-hash=844d7bbb7f
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get pod -o wide --show-labels
    NAME                                READY   STATUS             RESTARTS   AGE    IP            NODE         NOMINATED NODE   READINESS GATES   LABELS
    nginx-deployment-55c7bdfb86-bwzk9   1/1     Running            0          10m    10.244.4.49   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=55c7bdfb86
    nginx-deployment-55c7bdfb86-cmvzg   1/1     Running            0          10m    10.244.2.55   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=55c7bdfb86
    nginx-deployment-55c7bdfb86-kjrrw   1/1     Running            0          10m    10.244.2.56   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=55c7bdfb86
    nginx-deployment-844d7bbb7f-pctwr   0/1     ImagePullBackOff   0          2m3s   10.244.4.51   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=844d7bbb7f

**需求：回滚到以前稳定的 Deployment 版本。**

操作步骤如下：

检查 Deployment 修改历史

[root@k8s-master controller]# kubectl rollout history deployment/nginx-deployment
    deployment.apps/nginx-deployment
    REVISION  CHANGE-CAUSE
    1         kubectl apply --filename=nginx-deployment.yaml --record=true
    2         kubectl set image deployment/nginx-deployment nginx=registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5 --record=true
    3         kubectl set image deployment/nginx-deployment nginx=registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17 --record=true
    4         kubectl set image deployment/nginx-deployment nginx=registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.1710 --record=true

查看修改历史的详细信息，运行

[root@k8s-master controller]# kubectl rollout history deployment/nginx-deployment --revision=3
    deployment.apps/nginx-deployment with revision #3
    Pod Template:
      Labels:    app=nginx
        pod-template-hash=55c7bdfb86
      Annotations:    kubernetes.io/change-cause:
          kubectl set image deployment/nginx-deployment nginx=registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17 --record=true
      Containers:
       nginx:
        Image:    registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17
        Port:    80/TCP
        Host Port:    0/TCP
        Environment:    <none>
        Mounts:    <none>
      Volumes:    <none>

**回滚到上一次修改（即版本 3）或指定版本**

现在已决定撤消当前更新并回滚到以前的版本

# 回滚到上一版本
    [root@k8s-master controller]# kubectl rollout undo deployment/nginx-deployment
    deployment.apps/nginx-deployment rolled back
    # 回滚到指定历史版本
    [root@k8s-master controller]# kubectl rollout undo deployment/nginx-deployment --to-revision=2
    deployment.apps/nginx-deployment rolled back

检查回滚是否成功、 Deployment 是否正在运行

[root@k8s-master controller]# kubectl get deploy -o wide --show-labels
    NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                          SELECTOR    LABELS
    nginx-deployment   3/3     3            3           17h   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5   app=nginx   app=nginx

获取 Deployment 描述信息

[root@k8s-master controller]# kubectl describe deployment
    Name:                   nginx-deployment
    Namespace:              default
    CreationTimestamp:      Thu, 28 May 2020 00:04:09 +0800
    Labels:                 app=nginx
    Annotations:            deployment.kubernetes.io/revision: 7
                            kubectl.kubernetes.io/last-applied-configuration:
                              { "apiVersion":"apps/v1","kind":"Deployment","metadata":{ "annotations":{ "kubernetes.io/change-cause":"kubectl apply --filename=nginx-deploy...
                            kubernetes.io/change-cause:
                              kubectl set image deployment/nginx-deployment nginx=registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5 --record=true
    Selector:               app=nginx
    Replicas:               3 desired | 3 updated | 3 total | 3 available | 0 unavailable
    StrategyType:           RollingUpdate
    MinReadySeconds:        0
    RollingUpdateStrategy:  25% max unavailable, 25% max surge
    Pod Template:
      Labels:  app=nginx
      Containers:
       nginx:
        Image:        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5
        Port:         80/TCP
        Host Port:    0/TCP
        Environment:  <none>
        Mounts:       <none>
      Volumes:        <none>
    Conditions:
      Type           Status  Reason
      ----           ------  ------
      Available      True    MinimumReplicasAvailable
      Progressing    True    NewReplicaSetAvailable
    OldReplicaSets:  <none>
    NewReplicaSet:   nginx-deployment-56d78686f5 (3/3 replicas created)
    Events:
      Type    Reason             Age                 From                   Message
      ----    ------             ----                ----                   -------
    ………………
      Normal  ScalingReplicaSet  107s                deployment-controller  Scaled up replica set nginx-deployment-56d78686f5 to 1
      Normal  ScalingReplicaSet  104s                deployment-controller  Scaled down replica set nginx-deployment-55c7bdfb86 to 2
      Normal  ScalingReplicaSet  104s                deployment-controller  Scaled up replica set nginx-deployment-56d78686f5 to 2
      Normal  ScalingReplicaSet  103s                deployment-controller  Scaled down replica set nginx-deployment-55c7bdfb86 to 1
      Normal  ScalingReplicaSet  103s                deployment-controller  Scaled up replica set nginx-deployment-56d78686f5 to 3
      Normal  ScalingReplicaSet  102s                deployment-controller  Scaled down replica set nginx-deployment-55c7bdfb86 to 0

## 2.7 扩容/缩容Deployment ##

操作过程如下

[root@k8s-master controller]# kubectl scale deployment/nginx-deployment --replicas=10
    deployment.apps/nginx-deployment scaled
    [root@k8s-master controller]# kubectl get deploy -o wide --show-labels
    NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                          SELECTOR    LABELS
    nginx-deployment   10/10   10           10          17h   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5   app=nginx   app=nginx
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get rs -o wide --show-labels
    NAME                          DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                          SELECTOR                                 LABELS
    nginx-deployment-55c7bdfb86   0         0         0       17h   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17     app=nginx,pod-template-hash=55c7bdfb86   app=nginx,pod-template-hash=55c7bdfb86
    nginx-deployment-56d78686f5   10        10        10      17h   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.5   app=nginx,pod-template-hash=56d78686f5   app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-76b9d6bcf5   0         0         0       17h   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.17.1   app=nginx,pod-template-hash=76b9d6bcf5   app=nginx,pod-template-hash=76b9d6bcf5
    nginx-deployment-844d7bbb7f   0         0         0       17h   nginx        registry.cn-beijing.aliyuncs.com/google_registry/nginx:1.1710   app=nginx,pod-template-hash=844d7bbb7f   app=nginx,pod-template-hash=844d7bbb7f
    [root@k8s-master controller]#
    [root@k8s-master controller]# kubectl get pod -o wide --show-labels
    NAME                                READY   STATUS    RESTARTS   AGE   IP            NODE         NOMINATED NODE   READINESS GATES   LABELS
    nginx-deployment-56d78686f5-4v5mj   1/1     Running   0          44s   10.244.2.64   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-8m7mx   1/1     Running   0          44s   10.244.4.60   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-c7wlb   1/1     Running   0          44s   10.244.4.59   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-jg5lt   1/1     Running   0          44s   10.244.2.63   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-jj58d   1/1     Running   0          11m   10.244.4.56   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-k2kts   1/1     Running   0          11m   10.244.4.57   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-qltkv   1/1     Running   0          44s   10.244.2.61   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-r7vmm   1/1     Running   0          11m   10.244.2.60   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-rxlpm   1/1     Running   0          44s   10.244.2.62   k8s-node02   <none>           <none>            app=nginx,pod-template-hash=56d78686f5
    nginx-deployment-56d78686f5-vlzrf   1/1     Running   0          44s   10.244.4.58   k8s-node01   <none>           <none>            app=nginx,pod-template-hash=56d78686f5

## 2.8 清理策略Policy ##

可以在 Deployment 中设置 .spec.revisionHistoryLimit，以指定保留多少该 Deployment 的 ReplicaSets数量。其余的将在后台进行垃圾回收。默认情况下，是10。

注意：此字段设置为 0 将导致清理 Deployment 的所有历史记录，因此 Deployment 将无法通过命令行回滚。

# 3、 升级回滚 #

# 应用升级
    kubectl set image deployment web nginx=nginx:1.15
    
    # 查看升级状态
    kubectl rollout status deployment web
    
    # 查看升级的历史版本
    kubectl rollout history deployment web
    
    # 回滚，还原到上一个版本
    kubectl rollout undo deployment web
    
    # 回滚到指定的版本
    kubectl rollout undo deployment web --to-version=2

# 3、 弹性伸缩 #

# 弹性伸缩
    kubectl scale deployment web --replicas=10

# 案例 #

#### 1. 创建deployment ####

[root@hdss7-200 deployment]# vim /data/k8s-yaml/base_resource/deployment/nginx-v1.12.yaml
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx-deploy
      namespace: app
    spec:
      replicas: 5
      selector:
        matchLabels:
          app: nginx
          release: stable
          tier: slb
          partition: website
      strategy:
        rollingUpdate:
          maxSurge: 1
          maxUnavailable: 0
      template:
        metadata:
          labels:
            app: nginx
            release: stable
            tier: slb
            partition: website
            version: v1.12
        spec:
          containers:
          - name: nginx-pod
            image: harbor.od.com/public/nginx:v1.12
            lifecycle:
              postStart:
                exec:
                  command:
                    - /bin/bash
                    - -c
                    - "echo 'health check ok!' > /usr/share/nginx/html/health.html"
            readinessProbe: 
              initialDelaySeconds: 5
              httpGet:
                port: 80
                path: /health.html
            livenessProbe:
              initialDelaySeconds: 10
              periodSeconds: 5
              httpGet:
                port: 80
                path: /health.html

[root@hdss7-21 ~]# kubectl apply -f http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.12.yaml --record
    
    [root@hdss7-21 ~]# kubectl get pods -n app -l partition=website # 查看
    NAME                           READY   STATUS    RESTARTS   AGE
    nginx-deploy-5597c8b45-425ms   1/1     Running   0          5m12s
    nginx-deploy-5597c8b45-5p2rz   1/1     Running   0          9m34s
    nginx-deploy-5597c8b45-dw7hd   1/1     Running   0          9m34s
    nginx-deploy-5597c8b45-fg82k   1/1     Running   0          5m12s
    nginx-deploy-5597c8b45-sfxmg   1/1     Running   0          9m34s
    [root@hdss7-21 ~]# kubectl get rs -n app -l partition=website -o wide
    NAME                     DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                             SELECTOR
    nginx-deploy-5597c8b45   8         8         8       10m   nginx-pod    harbor.od.com/public/nginx:v1.12   app=nginx,partition=website,pod-template-hash=5597c8b45,release=stable,tier=slb
    [root@hdss7-21 ~]# kubectl get deployment -n app -o wide
    NAME           READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                             SELECTOR
    nginx-deploy   8/8     8            8           11m   nginx-pod    harbor.od.com/public/nginx:v1.12   app=nginx,partition=website,release=stable,tier=slb

#### 2. 模拟蓝绿发布 ####

apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx-deploy
      namespace: app
    spec:
      replicas: 5
      selector:
        matchLabels:
          app: nginx
          release: stable
          tier: slb
          partition: website
      strategy:
        rollingUpdate:
          # 最大浪涌数量为5
          maxSurge: 5
          maxUnavailable: 0
      template:
        metadata:
          labels:
            app: nginx
            release: stable
            tier: slb
            partition: website
            # 修改版本信息，用于查看当前版本
            version: v1.13
        spec:
          containers:
          - name: nginx-pod
            # 修改镜像
            image: harbor.od.com/public/nginx:v1.13
            lifecycle:
              postStart:
                exec:
                  command:
                    - /bin/bash
                    - -c
                    - "echo 'health check ok!' > /usr/share/nginx/html/health.html"
            readinessProbe: 
              initialDelaySeconds: 5
              httpGet:
                port: 80
                path: /health.html
            livenessProbe:
              initialDelaySeconds: 10
              periodSeconds: 5
              httpGet:
                port: 80
                path: /health.html

[root@hdss7-21 ~]# kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.13.yaml --record=true
    [root@hdss7-21 ~]# kubectl rollout history deployment nginx-deploy -n app
    REVISION  CHANGE-CAUSE
    1         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.12.yaml --record=true
    2         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.13.yaml --record=true
    [root@hdss7-21 ~]# kubectl get rs -n app -l tier=slb -L version # 多个ReplicaSet对应不同版本
    NAME                      DESIRED   CURRENT   READY   AGE     VERSION
    nginx-deploy-5597c8b45    0         0         0       10m     v1.12
    nginx-deploy-6bd88df699   5         5         5       9m31s   v1.13

# 升级过程中的状态变化:
    [root@hdss7-21 ~]# kubectl rollout status deployment nginx-deploy -n app 
    Waiting for deployment "nginx-deploy" rollout to finish: 5 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 5 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 5 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 4 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 4 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 4 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 3 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 3 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 3 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 2 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 2 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 2 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "nginx-deploy" rollout to finish: 1 old replicas are pending termination...
    deployment "nginx-deploy" successfully rolled out
    [root@hdss7-21 ~]# kubectl get pod -n app -l partition=website -L version -w
    NAME                           READY   STATUS    RESTARTS   AGE   VERSION
    nginx-deploy-5597c8b45-t5plt   1/1     Running   0          19s   v1.12
    nginx-deploy-5597c8b45-tcq69   1/1     Running   0          19s   v1.12
    nginx-deploy-5597c8b45-vdjxg   1/1     Running   0          19s   v1.12
    nginx-deploy-5597c8b45-vqn9x   1/1     Running   0          19s   v1.12
    nginx-deploy-5597c8b45-zl6qr   1/1     Running   0          19s   v1.12
    ---- 立刻创建5个新版本pod，Pending调度中
    nginx-deploy-6bd88df699-242fr   0/1     Pending   0          0s    v1.13
    nginx-deploy-6bd88df699-242fr   0/1     Pending   0          0s    v1.13
    nginx-deploy-6bd88df699-8pmdg   0/1     Pending   0          0s    v1.13
    nginx-deploy-6bd88df699-4kj8z   0/1     Pending   0          0s    v1.13
    nginx-deploy-6bd88df699-n7x6n   0/1     Pending   0          0s    v1.13
    nginx-deploy-6bd88df699-8pmdg   0/1     Pending   0          0s    v1.13
    nginx-deploy-6bd88df699-4kj8z   0/1     Pending   0          0s    v1.13
    nginx-deploy-6bd88df699-8j85n   0/1     Pending   0          0s    v1.13
    nginx-deploy-6bd88df699-n7x6n   0/1     Pending   0          0s    v1.13
    nginx-deploy-6bd88df699-8j85n   0/1     Pending   0          0s    v1.13
    ---- 创建pod中
    nginx-deploy-6bd88df699-242fr   0/1     ContainerCreating   0          0s    v1.13
    nginx-deploy-6bd88df699-8pmdg   0/1     ContainerCreating   0          0s    v1.13
    nginx-deploy-6bd88df699-4kj8z   0/1     ContainerCreating   0          0s    v1.13
    nginx-deploy-6bd88df699-n7x6n   0/1     ContainerCreating   0          0s    v1.13
    nginx-deploy-6bd88df699-8j85n   0/1     ContainerCreating   0          0s    v1.13
    ---- 启动pod
    nginx-deploy-6bd88df699-242fr   0/1     Running             0          1s    v1.13
    nginx-deploy-6bd88df699-8j85n   0/1     Running             0          1s    v1.13
    nginx-deploy-6bd88df699-4kj8z   0/1     Running             0          1s    v1.13
    nginx-deploy-6bd88df699-n7x6n   0/1     Running             0          1s    v1.13
    nginx-deploy-6bd88df699-8pmdg   0/1     Running             0          1s    v1.13
    ---- Pod逐个就绪，且替换旧版本的pod
    nginx-deploy-6bd88df699-242fr   1/1     Running             0          6s    v1.13
    nginx-deploy-5597c8b45-t5plt    1/1     Terminating         0          50s   v1.12
    nginx-deploy-6bd88df699-8j85n   1/1     Running             0          7s    v1.13
    nginx-deploy-5597c8b45-vdjxg    1/1     Terminating         0          51s   v1.12
    nginx-deploy-5597c8b45-t5plt    0/1     Terminating         0          51s   v1.12
    nginx-deploy-5597c8b45-t5plt    0/1     Terminating         0          51s   v1.12
    nginx-deploy-6bd88df699-4kj8z   1/1     Running             0          7s    v1.13
    nginx-deploy-5597c8b45-zl6qr    1/1     Terminating         0          51s   v1.12
    nginx-deploy-5597c8b45-vdjxg    0/1     Terminating         0          52s   v1.12
    nginx-deploy-5597c8b45-vdjxg    0/1     Terminating         0          52s   v1.12
    nginx-deploy-5597c8b45-zl6qr    0/1     Terminating         0          53s   v1.12
    nginx-deploy-5597c8b45-t5plt    0/1     Terminating         0          54s   v1.12
    nginx-deploy-5597c8b45-t5plt    0/1     Terminating         0          54s   v1.12
    nginx-deploy-5597c8b45-zl6qr    0/1     Terminating         0          56s   v1.12
    nginx-deploy-5597c8b45-zl6qr    0/1     Terminating         0          56s   v1.12
    nginx-deploy-6bd88df699-n7x6n   1/1     Running             0          13s   v1.13
    nginx-deploy-5597c8b45-tcq69    1/1     Terminating         0          57s   v1.12
    nginx-deploy-5597c8b45-tcq69    0/1     Terminating         0          58s   v1.12
    nginx-deploy-5597c8b45-tcq69    0/1     Terminating         0          59s   v1.12
    nginx-deploy-6bd88df699-8pmdg   1/1     Running             0          15s   v1.13
    nginx-deploy-5597c8b45-vqn9x    1/1     Terminating         0          59s   v1.12
    nginx-deploy-5597c8b45-vqn9x    0/1     Terminating         0          60s   v1.12
    nginx-deploy-5597c8b45-vqn9x    0/1     Terminating         0          61s   v1.12
    nginx-deploy-5597c8b45-vqn9x    0/1     Terminating         0          61s   v1.12
    nginx-deploy-5597c8b45-vdjxg    0/1     Terminating         0          64s   v1.12
    nginx-deploy-5597c8b45-vdjxg    0/1     Terminating         0          64s   v1.12
    nginx-deploy-5597c8b45-tcq69    0/1     Terminating         0          64s   v1.12
    nginx-deploy-5597c8b45-tcq69    0/1     Terminating         0          64s   v1.12

#### 3. 滚动发布 ####

通过定义 maxsurge 和 maxUnavailable 来实现滚动升级的速度，滚动升级中，可以使用 kubectl rollout pause 来实现暂停。

[root@hdss7-200 deployment]# vim /data/k8s-yaml/base_resource/deployment/nginx-v1.14.yaml
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx-deploy
      namespace: app
    spec:
      replicas: 5
      selector:
        matchLabels:
          app: nginx
          release: stable
          tier: slb
          partition: website
      strategy:
        rollingUpdate:
          # 以下两项，控制升级速度
          maxSurge: 1
          maxUnavailable: 0
      template:
        metadata:
          labels:
            app: nginx
            release: stable
            tier: slb
            partition: website
            # 修改版本
            version: v1.14
        spec:
          containers:
          - name: nginx-pod
            # 修改镜像版本
            image: harbor.od.com/public/nginx:v1.14
            lifecycle:
              postStart:
                exec:
                  command:
                    - /bin/bash
                    - -c
                    - "echo 'health check ok!' > /usr/share/nginx/html/health.html"
            readinessProbe: 
              initialDelaySeconds: 5
              httpGet:
                port: 80
                path: /health.html
            livenessProbe:
              initialDelaySeconds: 10
              periodSeconds: 5
              httpGet:
                port: 80
                path: /health.html

[root@hdss7-21 ~]# kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.14.yaml --record=true
    [root@hdss7-21 ~]# kubectl get rs -n app -l tier=slb -L version # replicaset 数量增加
    NAME                      DESIRED   CURRENT   READY   AGE    VERSION
    nginx-deploy-5597c8b45    0         0         0       155m   v1.12
    nginx-deploy-6bd88df699   0         0         0       154m   v1.13
    nginx-deploy-7c5976dcd9   5         5         5       83s    v1.14
    [root@hdss7-21 ~]# kubectl rollout history deployment nginx-deploy -n app # 升级记录
    REVISION  CHANGE-CAUSE
    1         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.12.yaml --record=true
    2         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.13.yaml --record=true
    3         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.14.yaml --record=true

[root@hdss7-21 ~]# kubectl get pod -n app -l partition=website -L version -w # 逐个滚动升级
    NAME                            READY   STATUS    RESTARTS   AGE    VERSION
    nginx-deploy-6bd88df699-242fr   1/1     Running   0          152m   v1.13
    nginx-deploy-6bd88df699-4kj8z   1/1     Running   0          152m   v1.13
    nginx-deploy-6bd88df699-8j85n   1/1     Running   0          152m   v1.13
    nginx-deploy-6bd88df699-8pmdg   1/1     Running   0          152m   v1.13
    nginx-deploy-6bd88df699-n7x6n   1/1     Running   0          152m   v1.13
    nginx-deploy-7c5976dcd9-ttlqx   0/1     Pending   0          0s     v1.14
    nginx-deploy-7c5976dcd9-ttlqx   0/1     Pending   0          0s     v1.14
    nginx-deploy-7c5976dcd9-ttlqx   0/1     ContainerCreating   0          0s     v1.14
    nginx-deploy-7c5976dcd9-ttlqx   0/1     Running             0          1s     v1.14
    nginx-deploy-7c5976dcd9-ttlqx   1/1     Running             0          9s     v1.14
    nginx-deploy-6bd88df699-8pmdg   1/1     Terminating         0          153m   v1.13
    ......

#### 4. 模拟灰度(金丝雀)发布 ####

灰度发布在不同场景中实现方式不同，如果当前灰度机器仅对测试开放，可以定义一个新的deployment来配合service来实现。如果需要切入一部分随机真实用户的流量，可以将生产机器中一台机器作为灰度机器，通过灰度后再升级其它的机器。

# nginx-v1.15.yaml 与 nginx-v1.14.yaml 一致，仅仅修改了镜像文件
    [root@hdss7-21 ~]# kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.15.yaml --record=true && kubectl rollout pause deployment nginx-deploy -n app
    [root@hdss7-21 ~]# kubectl rollout history deployment nginx-deploy -n app
    REVISION  CHANGE-CAUSE
    1         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.12.yaml --record=true
    2         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.13.yaml --record=true
    3         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.14.yaml --record=true
    4         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.15.yaml --record=true
    [root@hdss7-21 ~]# kubectl get rs -n app -l tier=slb -L version # 存在两个ReplicaSet对外提供服务
    NAME                      DESIRED   CURRENT   READY   AGE     VERSION
    nginx-deploy-5597c8b45    0         0         0       177m    v1.12
    nginx-deploy-6695fd9655   1         1         1       2m22s   v1.15
    nginx-deploy-6bd88df699   0         0         0       176m    v1.13
    nginx-deploy-7c5976dcd9   5         5         5       23m     v1.14
    [root@hdss7-21 ~]# kubectl get pod -n app -l partition=website -L version -w # 新老共存
    NAME                            READY   STATUS    RESTARTS   AGE   VERSION
    nginx-deploy-6695fd9655-tcm76   1/1     Running   0          17s   v1.15
    nginx-deploy-7c5976dcd9-4tnv4   1/1     Running   0          21m   v1.14
    nginx-deploy-7c5976dcd9-bpjc2   1/1     Running   0          20m   v1.14
    nginx-deploy-7c5976dcd9-gv8qm   1/1     Running   0          20m   v1.14
    nginx-deploy-7c5976dcd9-ttlqx   1/1     Running   0          21m   v1.14
    nginx-deploy-7c5976dcd9-xq2qs   1/1     Running   0          21m   v1.14

# 手动暂停
    [root@hdss7-21 ~]# kubectl rollout resume deployment nginx-deploy -n app && kubectl rollout pause deployment nginx-deploy -n app
    [root@hdss7-21 ~]# kubectl get pod -n app -l partition=website -L version -w
    NAME                            READY   STATUS    RESTARTS   AGE     VERSION
    nginx-deploy-6695fd9655-jmb94   1/1     Running   0          19s     v1.15
    nginx-deploy-6695fd9655-tcm76   1/1     Running   0          6m19s   v1.15
    nginx-deploy-7c5976dcd9-4tnv4   1/1     Running   0          27m     v1.14
    nginx-deploy-7c5976dcd9-gv8qm   1/1     Running   0          26m     v1.14
    nginx-deploy-7c5976dcd9-ttlqx   1/1     Running   0          27m     v1.14
    nginx-deploy-7c5976dcd9-xq2qs   1/1     Running   0          27m     v1.14
    # 升级剩余所有机器
    [root@hdss7-21 ~]# kubectl rollout resume deployment nginx-deploy -n app

#### 5. 版本回滚 ####

当升级出现异常时，执行回滚即可。

[root@hdss7-21 ~]# kubectl rollout history deployment nginx-deploy -n app # 查看历史版本记录
    deployment.extensions/nginx-deploy 
    REVISION  CHANGE-CAUSE
    1         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.12.yaml --record=true
    2         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.13.yaml --record=true
    3         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.14.yaml --record=true
    4         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.15.yaml --record=true
    [root@hdss7-21 ~]# kubectl rollout undo deployment nginx-deploy -n app
    [root@hdss7-21 ~]# kubectl rollout history deployment nginx-deploy -n app # 版本3已经被版本5替代
    deployment.extensions/nginx-deploy 
    REVISION  CHANGE-CAUSE
    1         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.12.yaml --record=true
    2         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.13.yaml --record=true
    4         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.15.yaml --record=true
    5         kubectl apply --filename=http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.14.yaml --record=true
    [root@hdss7-21 ~]# kubectl get pod -n app -l partition=website -L version 
    NAME                            READY   STATUS    RESTARTS   AGE     VERSION
    nginx-deploy-7c5976dcd9-2kps8   1/1     Running   0          2m20s   v1.14
    nginx-deploy-7c5976dcd9-bqs28   1/1     Running   0          2m6s    v1.14
    nginx-deploy-7c5976dcd9-jdvps   1/1     Running   0          2m13s   v1.14
    nginx-deploy-7c5976dcd9-vs8l4   1/1     Running   0          116s    v1.14
    nginx-deploy-7c5976dcd9-z99mb   1/1     Running   0          101s    v1.14
    [root@hdss7-21 ~]# kubectl get rs -n app -l tier=slb -L version
    NAME                      DESIRED   CURRENT   READY   AGE    VERSION
    nginx-deploy-5597c8b45    0         0         0       3h7m   v1.12
    nginx-deploy-6695fd9655   0         0         0       12m    v1.15
    nginx-deploy-6bd88df699   0         0         0       3h7m   v1.13
    nginx-deploy-7c5976dcd9   5         5         5       34m    v1.14

#### 6. 常用命令 ####

kubectl rollout status deployment nginx-deploy -n app  # 查看版本升级过程
    kubectl rollout history deployment nginx-deploy -n app # 查看版本升级历史
    kubectl apply -f http://k8s-yaml.od.com/base_resource/deployment/nginx-v1.15.yaml --record=true  # 升级且记录升级命令
    kubectl rollout undo deployment nginx-deploy -n app    # 回滚到上个版本
    kubectl rollout undo deployment nginx-deploy --to-revision=3 -n app # 回滚到版本3

[image.png]: /images/20221120/4f7c604c55b04c03914de7bf93c01c03.png
[image.png 1]: /images/20221120/9fdd095263924d56a6c01f6f945ef438.png
[image.png 2]: /images/20221120/5f2f82e825d84a54a2da0f052bede154.png
[image.png 3]: /images/20221120/8b442f5c96684fb7a13704f423279697.png