Pod控制器介绍
Pod是kubernetes的最小管理单元,在kubernetes中,按照pod的创建方式可以将其分为两类:
-
**自主式pod:**kubernetes直接创建出来的Pod,这种pod删除后就没有了,也不会重建
-
**控制器创建的pod【主流】:**kubernetes通过控制器创建的pod,这种pod删除了之后还会自动重建
什么是Pod控制器
Pod控制器是管理pod的中间层,使用Pod控制器之后,只需要告诉Pod控制器,想要多少个什么样的Pod就可以了,它会创建出满足条件的Pod并确保每一个Pod资源处于用户期望的目标状态。如果Pod资源在运行中出现故障,它会基于指定策略重新编排Pod。
在kubernetes中,有很多类型的pod控制器,每种都有自己的适合的场景,常见的有下面这些:
- ReplicationController:比较原始的pod控制器,已经被废弃,由ReplicaSet替代
- ReplicaSet:保证副本数量一直维持在期望值,并支持pod数量扩缩容,镜像版本升级
- **Deployment:**通过控制ReplicaSet来控制Pod,并支持滚动升级、回退版本
- Horizontal Pod Autoscaler:可以根据集群负载自动水平调整Pod的数量,实现削峰填谷
- DaemonSet:在集群中的指定Node上运行且仅运行一个副本,一般用于守护进程类的任务
- Job:它创建出来的pod只要完成任务就立即退出,不需要重启或重建,用于执行一次性任务
- Cronjob:它创建的Pod负责周期性任务控制,不需要持续后台运行
- StatefulSet:管理有状态应用
ReplicaSet(RS)
RS概述
ReplicaSet的主要作用是保证一定数量的pod正常运行,它会持续监听这些Pod的运行状态,一旦Pod发生故障,就会重启或重建。同时它还支持对pod数量的扩缩容和镜像版本的升降级。

ReplicaSet的资源清单文件:
apiVersion: apps/v1 # 版本号
kind: ReplicaSet # 类型
metadata: # 元数据
name: # rs名称
namespace: # 所属命名空间
labels: #标签
controller: rs
spec: # 详情描述
replicas: 3 # 副本数量
selector: # 选择器,通过它指定该控制器管理哪些pod
matchLabels: # Labels匹配规则
app: nginx-pod
matchExpressions: # Expressions匹配规则
- { key: app, operator: In, values: [ nginx-pod ] }
template: # 模板,当副本数量不足时,会根据下面的模板创建pod副本
metadata:
labels:
app: nginx-pod
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80

在里面,需要新了解的配置项就是spec下面几个选项:
- replicas:指定副本数量,其实就是当前rs创建出来的pod的数量,默认为1
- selector:选择器,它的作用是建立pod控制器和pod之间的关联关系,采用的Label 。Selector机制在pod模板上定义label,在控制器上定义选择器,就可以表明当前控制器能管理哪些pod了
- template:模板,就是当前控制器创建pod所使用的模板板,里面其实就是专栏pod详解学的定义
创建与删除RS
创建rs-controller.yaml文件,内容如下:
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: rs-controller
namespace: dev
spec:
replicas: 3
selector:
matchLabels:
app: nginx-pod
template:
metadata:
labels:
app: nginx-pod
spec:
containers:
- name: nginx
image: nginx
创建RS
bash
# 创建rs
[root@master k8sYamlForCSDN]# kubectl apply -f rs-controller.yaml
replicaset.apps/rs-controller created
# 查看rs
# DESIRED:期望副本数量
# CURRENT:当前副本数量
# READY:已经准备好提供服务的副本数量
[root@master k8sYamlForCSDN]# kubectl get rs rs-controller -n dev -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
rs-controller 3 3 3 75s nginx nginx app=nginx-pod
# 查看当前控制器创建出来的pod
# 这里发现控制器创建出来的pod的名称是在控制器名称后面拼接了-xxxxx随机码
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
rs-controller-rr598 1/1 Running 0 47s
rs-controller-tmfd7 1/1 Running 0 47s
rs-controller-xgrst 1/1 Running 0 47s
删除RS
bash
# 只推荐第一种,第二三种做了解即可
# 1. 使用yaml直接删除(推荐)
[root@master k8sYamlForCSDN]# kubectl delete -f rs-controller.yaml
replicaset.apps "rs-controller" deleted
# 2. 使用kubectl delete命令会删除此RS以及它管理的Pod
# 在kubernetes删除RS前,会将RS的replicasclear调整为0,等待所有的Pod被删除后,在执行RS对象的删除
[root@master k8sYamlForCSDN]# kubectl delete rs rs-controller -n dev
replicaset.apps "rs-controller" deleted
[root@master k8sYamlForCSDN]# kubectl get pod -n dev
No resources found in dev namespace.
# 3. 如果希望只删除RS对象,而留下正在运行的pod,需要在kubectl delete命令的时候增加--cascade=orphan选项
[root@master k8sYamlForCSDN]# kubectl get rs -n dev
NAME DESIRED CURRENT READY AGE
rs-controller 6 6 3 15s
[root@master k8sYamlForCSDN]# kubectl delete rs rs-controller -n dev --cascade=orphan
replicaset.apps "rs-controller" deleted
[root@master k8sYamlForCSDN]# kubectl get rs -n dev
No resources found in dev namespace.
[root@master k8sYamlForCSDN]# kubectl get pod -n dev
NAME READY STATUS RESTARTS AGE
rs-controller-9h5zd 1/1 Running 0 38s
rs-controller-jk4h6 1/1 Running 0 38s
rs-controller-lmlwn 1/1 Running 0 38s
扩缩容
bash
# 第一种方式
# 修改yaml文件,把replicas=3改成1,重新apply,此时rs会更新
[root@master k8sYamlForCSDN]# kubectl apply -f rs-controller.yaml
replicaset.apps/rs-controller created
[root@master k8sYamlForCSDN]# vi rs-controller.yaml
[root@master k8sYamlForCSDN]# kubectl apply -f rs-controller.yaml
replicaset.apps/rs-controller configured
# 命令运行完毕,立即查看,发现已经有2个开始准备退出了
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
rs-controller-h654s 0/1 Terminating 0 18s
rs-controller-l67tb 0/1 Terminating 0 18s
rs-controller-s4g7b 1/1 Running 0 18s
# 稍等片刻,就只剩下1个了
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
rs-controller-s4g7b 1/1 Running 0 81s
# 第二种方式
# 编辑rs的副本数量,修改spec:replicas: 2即可,注意用这种方法,yaml文件中的数量是不改变的
[root@master k8sYamlForCSDN]# kubectl edit rs rs-controller -n dev
replicaset.apps/rs-controller edited
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
rs-controller-9mf77 1/1 Running 0 26s
rs-controller-s4g7b 1/1 Running 0 3m23s
# 第三种方式
# 使用scale命令实现,后面--replicas=n直接指定目标数量即可,注意用这种方法,yaml文件中的数量是不改变的
[root@master k8sYamlForCSDN]# kubectl scale rs rs-controller -n dev --replicas=3
replicaset.apps/rs-controller scaled
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
rs-controller-7d9wf 0/1 ContainerCreating 0 6s
rs-controller-9mf77 1/1 Running 0 119s
rs-controller-s4g7b 1/1 Running 0 4m56s
镜像升级
bash
# 第一种方式(推荐)
# 修改yaml文件,把image=nginx改成nginx:1.17.1,重新apply,此时rs会更新
[root@master k8sYamlForCSDN]# vi rs-controller.yaml
[root@master k8sYamlForCSDN]# kubectl apply -f rs-controller.yaml
replicaset.apps/rs-controller configured
[root@master k8sYamlForCSDN]# kubectl get rs -n dev -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES
rs-controller 1 1 1 6m42s nginx nginx:1.17.1
# 第二种方式
# 编辑rs的image,修改imagenginx:1.17.2即可,注意用这种方法,yaml文件中的配置是不改变的
[root@master k8sYamlForCSDN]# kubectl edit rs rs-controller -n dev
replicaset.apps/rs-controller edited
[root@master k8sYamlForCSDN]# kubectl get rs -n dev -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES
rs-controller 1 1 1 8m41s nginx nginx:1.17.2
# 第三种方式,也可以使用命令完成这个工作
# kubectl set image rs rs名称 容器=镜像版本 -n namespace
[root@master k8sYamlForCSDN]# kubectl set image rs rs-controller -n dev nginx=nginx:1.17.3
replicaset.apps/rs-controller image updated
[root@master k8sYamlForCSDN]# kubectl get rs -n dev -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES
rs-controller 1 1 1 9m50s nginx nginx:1.17.3
Deployment
Deploy概述
为了更好的解决服务编排的问题,kubernetes在V1.2版本开始,引入了Deployment控制器。这种控制器并不直接管理pod,而是通过管理ReplicaSet来间接管理Pod,即:Deployment管理ReplicaSet,ReplicaSet管理Pod。所以Deployment比ReplicaSet功能更加强大。

Deployment主要功能有下面几个:
- 支持ReplicaSet的所有功能
- 支持发布的停止、继续
- 支持滚动升级和回滚版本
Deployment的资源清单文件:
bash
apiVersion: apps/v1 # 版本号
kind: Deployment # 类型
metadata: # 元数据
name: # Deploy名称
namespace: # 所属命名空间
labels: #标签
controller: deploy
spec: # 详情描述
replicas: 3 # 副本数量
revisionHistoryLimit: 3 # 保留历史版本(rs,用于版本回退)
paused: false # 暂停部署,默认是false
progressDeadlineSeconds: 600 # 部署超时时间(s),默认是600
strategy: # 策略
type: RollingUpdate # 滚动更新策略
rollingUpdate: # 滚动更新
maxSurge: 30% # 最大额外可以存在的副本数,可以为百分比,也可以为整数
maxUnavailable: 30% # 最大不可用状态的 Pod 的最大值,可以为百分比,也可以为整数
selector: # 选择器,通过它指定该控制器管理哪些pod
matchLabels: # Labels匹配规则
app: nginx-pod
matchExpressions: # Expressions匹配规则
- { key: app, operator: In, values: [ nginx-pod ] }
template: # 模板,当副本数量不足时,会根据下面的模板创建pod副本
metadata:
labels:
app: nginx-pod
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
创建deployment
创建deploy-controller.yaml,内容如下:
bash
apiVersion: apps/v1
kind: Deployment
metadata:
name: deploy-controller
namespace: dev
spec:
replicas: 3
selector:
matchLabels:
app: nginx-pod
template:
metadata:
labels:
app: nginx-pod
spec:
containers:
- name: nginx
image: nginx
bash
# 创建deployment
[root@master k8sYamlForCSDN]# kubectl apply -f deploy-controller.yaml
deployment.apps/deploy-controller created
# 查看deployment
# UP-TO-DATE 最新版本的pod的数量
# AVAILABLE 当前可用的pod的数量
[root@master k8sYamlForCSDN]# kubectl get deploy deploy-controller -n dev
NAME READY UP-TO-DATE AVAILABLE AGE
deploy-controller 3/3 3 3 40s
[root@master k8sYamlForCSDN]# kubectl get deployments.apps -n dev
NAME READY UP-TO-DATE AVAILABLE AGE
deploy-controller 3/3 3 3 47s
# 查看rs
# 发现rs的名称是在原来deployment的名字后面添加了一个10位数的随机串
[root@master k8sYamlForCSDN]# kubectl get rs -n dev
NAME DESIRED CURRENT READY AGE
deploy-controller-7f87645cd8 3 3 3 65s
# 查看pod
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
deploy-controller-7f87645cd8-28vcs 1/1 Running 0 73s
deploy-controller-7f87645cd8-dgnsb 1/1 Running 0 73s
deploy-controller-7f87645cd8-qfczb 1/1 Running 0 73s
[pod名=rs名+随机字符串]
[rs名=deploy名+随机字符串]
扩缩容
bash
# 第一种方式
# 修改yaml文件,把replicas=3改成2,重新apply,此时rs会更新
[root@master k8sYamlForCSDN]# vi deploy-controller.yaml
[root@master k8sYamlForCSDN]# kubectl apply -f deploy-controller.yaml
deployment.apps/deploy-controller configured
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
deploy-controller-7f87645cd8-dgnsb 1/1 Running 0 5m53s
deploy-controller-7f87645cd8-qfczb 1/1 Running 0 5m53s
# 第二种方式
# 编辑rs的副本数量,修改spec:replicas: 1即可,注意用这种方法,yaml文件中的数量是不改变的
[root@master k8sYamlForCSDN]# kubectl edit deploy deploy-controller -n dev
deployment.apps/deploy-controller edited
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
deploy-controller-7f87645cd8-qfczb 1/1 Running 0 7m56s
# 第三种方式
# 使用scale命令实现,后面--replicas=n直接指定目标数量即可,注意用这种方法,yaml文件中的数量是不改变的
[root@master k8sYamlForCSDN]# kubectl scale deploy deploy-controller -n dev --replicas=3
deployment.apps/deploy-controller scaled
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
deploy-controller-7f87645cd8-2dwpp 0/1 ContainerCreating 0 1s
deploy-controller-7f87645cd8-bb9xt 0/1 ContainerCreating 0 1s
deploy-controller-7f87645cd8-qfczb 1/1 Running 0 8m45s
镜像更新
deployment支持两种更新策略:
重建更新和滚动更新,可以通过strategy指定策略类型,支持两个属性:strategy:指定新的Pod替换旧的Pod的策略, 支持两个属性:
type:指定策略类型,支持两种策略
Recreate:在创建出新的Pod之前会先杀掉所有已存在的Pod
RollingUpdate:滚动更新,就是杀死一部分,就启动一部分,在更新过程中,存在两个版本PodrollingUpdate:当type为RollingUpdate时生效,用于为RollingUpdate设置参数,支持两个属性:
maxUnavailable:用来指定在升级过程中不可用Pod的最大数量,默认为25%。
maxSurge: 用来指定在升级过程中可以超过期望的Pod的最大数量,默认为25%。
重建更新:在创建出新的Pod之前会先杀掉所有已存在的Pod
- 编辑deploy-controller.yaml,在spec节点下添加更新策略
bash
apiVersion: apps/v1
kind: Deployment
metadata:
name: deploy-controller
namespace: dev
spec:
strategy: # 策略
type: Recreate # 重建更新
replicas: 3
selector:
matchLabels:
app: nginx-pod
template:
metadata:
labels:
app: nginx-pod
spec:
containers:
- name: nginx
image: nginx
- 创建deploy进行验证
bash
# 变更镜像
[root@master k8sYamlForCSDN]# kubectl get pods -n dev -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
deploy-controller-7f87645cd8-925wr 1/1 Running 0 35s 10.244.2.65 node2 <none> <none>
deploy-controller-7f87645cd8-l4f82 1/1 Running 0 35s 10.244.2.64 node2 <none> <none>
deploy-controller-7f87645cd8-ljwfx 1/1 Running 0 35s 10.244.1.44 node1 <none> <none>
[root@master k8sYamlForCSDN]# kubectl set image deploy deploy-controller -n dev nginx=nginx:1.17.1
deployment.apps/deploy-controller image updated
# 观察升级过程
[root@master k8sYamlForCSDN]# kubectl get pods -n dev -o wide -w
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
deploy-controller-7f87645cd8-925wr 1/1 Running 0 39s 10.244.2.65 node2 <none> <none>
deploy-controller-7f87645cd8-l4f82 1/1 Running 0 39s 10.244.2.64 node2 <none> <none>
deploy-controller-7f87645cd8-ljwfx 1/1 Running 0 39s 10.244.1.44 node1 <none> <none>
deploy-controller-7f87645cd8-925wr 1/1 Terminating 0 49s 10.244.2.65 node2 <none> <none>
deploy-controller-7f87645cd8-l4f82 1/1 Terminating 0 49s 10.244.2.64 node2 <none> <none>
deploy-controller-7f87645cd8-ljwfx 1/1 Terminating 0 49s 10.244.1.44 node1 <none> <none>
deploy-controller-6f44b7b85d-whjxq 0/1 Pending 0 0s <none> <none> <none> <none>
deploy-controller-6f44b7b85d-4nvzz 0/1 Pending 0 0s <none> <none> <none> <none>
deploy-controller-6f44b7b85d-hjk7x 0/1 Pending 0 0s <none> <none> <none> <none>
deploy-controller-6f44b7b85d-whjxq 0/1 ContainerCreating 0 0s <none> node1 <none> <none>
deploy-controller-6f44b7b85d-hjk7x 0/1 ContainerCreating 0 0s <none> node1 <none> <none>
deploy-controller-6f44b7b85d-4nvzz 0/1 ContainerCreating 0 0s <none> node2 <none> <none>
deploy-controller-6f44b7b85d-4nvzz 1/1 Running 0 2s 10.244.2.66 node2 <none> <none>
deploy-controller-6f44b7b85d-hjk7x 1/1 Running 0 16s 10.244.1.46 node1 <none> <none>
deploy-controller-6f44b7b85d-whjxq 1/1 Running 0 31s 10.244.1.45 node1 <none> <none>
滚动更新:滚动更新,就是杀死一部分,就启动一部分,在更新过程中,存在两个版本Pod
- 编辑deploy-controller.yaml,在spec节点下添加更新策略
bash
apiVersion: apps/v1
kind: Deployment
metadata:
name: deploy-controller
namespace: dev
spec:
strategy: # 策略
type: RollingUpdate # 滚动更新
rollingUpdate:
maxSurge: 25%
maxUnavailable: 25%
replicas: 3
selector:
matchLabels:
app: nginx-pod
template:
metadata:
labels:
app: nginx-pod
spec:
containers:
- name: nginx
image: nginx
-
创建deploy进行验证
bash# 创建deploy [root@master k8sYamlForCSDN]# kubectl apply -f deploy-controller.yaml deployment.apps/deploy-controller configured [root@master k8sYamlForCSDN]# kubectl get pods -n dev NAME READY STATUS RESTARTS AGE deploy-controller-7f87645cd8-4b2rf 1/1 Running 0 74s deploy-controller-7f87645cd8-7tqnr 1/1 Running 0 57s deploy-controller-7f87645cd8-cgmft 1/1 Running 0 55s # 更新镜像 [root@master k8sYamlForCSDN]# kubectl set image deploy deploy-controller -n dev nginx=nginx:1.17.1 deployment.apps/deploy-controller image updated # 滚动更新,不是先全杀掉在启动,而是一个杀掉,启动一个,滚动的形式 [root@master k8sYamlForCSDN]# kubectl get pods -n dev -o wide -w NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES deploy-controller-7f87645cd8-4b2rf 1/1 Running 0 86s 10.244.2.67 node2 <none> <none> deploy-controller-7f87645cd8-7tqnr 1/1 Running 0 69s 10.244.1.47 node1 <none> <none> deploy-controller-7f87645cd8-cgmft 1/1 Running 0 67s 10.244.1.48 node1 <none> <none> deploy-controller-6f44b7b85d-xckc9 0/1 Pending 0 0s <none> <none> <none> <none> deploy-controller-6f44b7b85d-xckc9 0/1 ContainerCreating 0 0s <none> node2 <none> <none> deploy-controller-6f44b7b85d-xckc9 1/1 Running 0 16s 10.244.2.68 node2 <none> <none> deploy-controller-7f87645cd8-7tqnr 1/1 Terminating 0 92s 10.244.1.47 node1 <none> <none> deploy-controller-6f44b7b85d-mxm5q 0/1 Pending 0 0s <none> node1 <none> <none> deploy-controller-6f44b7b85d-mxm5q 0/1 ContainerCreating 0 0s <none> node1 <none> <none> deploy-controller-6f44b7b85d-mxm5q 1/1 Running 0 17s 10.244.1.49 node1 <none> <none> deploy-controller-7f87645cd8-7tqnr 0/1 Terminating 0 93s 10.244.1.47 node1 <none> <none> deploy-controller-7f87645cd8-cgmft 1/1 Terminating 0 107s 10.244.1.48 node1 <none> <none> deploy-controller-6f44b7b85d-ftztf 0/1 Pending 0 0s <none> <none> <none> <none> deploy-controller-6f44b7b85d-ftztf 0/1 ContainerCreating 0 0s <none> node2 <none> <none> deploy-controller-7f87645cd8-cgmft 0/1 Terminating 0 108s 10.244.1.48 node1 <none> <none> deploy-controller-6f44b7b85d-ftztf 1/1 Running 0 17s 10.244.2.69 node2 <none> <none> deploy-controller-7f87645cd8-4b2rf 1/1 Terminating 0 2m23s 10.244.2.67 node2 <none> <none> # 至此,新版本的pod创建完毕,旧版本的pod销毁完毕 # 中间过程是滚动进行的,也就是边销毁边创建滚动更新的过程:

版本回退
镜像更新中rs的变化:
bash
# 创建deploy,并添加一个参数记录版本
[root@master k8sYamlForCSDN]# kubectl apply -f deploy-controller.yaml --record
Flag --record has been deprecated, --record will be removed in the future
deployment.apps/deploy-controller created
# 更新镜像
[root@master k8sYamlForCSDN]# kubectl set image deploy deploy-controller -n dev nginx=nginx:1.17.1
deployment.apps/deploy-controller image updated
# 查看RS
# 发现原来的RS中的pod被删除了,又重新创建了新的RS
[root@master k8sYamlForCSDN]# kubectl get rs -n dev -w
NAME DESIRED CURRENT READY AGE
deploy-controller-7f87645cd8 3 3 1 11s
...
deploy-controller-6f44b7b85d 3 3 3 35s
...
deploy-controller-7f87645cd8 0 0 0 90s
deployment支持版本升级过程中的暂停、继续功能以及版本回退等诸多功能,下面具体来看
kubectl rollout: 版本升级相关功能,支持下面的选项:
- status 显示当前升级状态
- history 显示 升级历史记录
- pause 暂停版本升级过程
- resume 继续已经暂停的版本升级过程
- restart 重启版本升级过程
- undo 回滚到上一级版本(可以使用--to-revision回滚到指定版本)
bash
# 查看当前升级版本的状态
[root@master k8sYamlForCSDN]# kubectl rollout status deployment deploy-controller -n dev
deployment "deploy-controller" successfully rolled out
# 查看升级历史记录
[root@master k8sYamlForCSDN]# kubectl rollout history deployment deploy-controller -n dev
deployment.apps/deploy-controller
REVISION CHANGE-CAUSE
1 kubectl apply --filename=deploy-controller.yaml --record=true
2 kubectl apply --filename=deploy-controller.yaml --record=true
# 升级镜像
[root@master k8sYamlForCSDN]# kubectl set image deploy deploy-controller -n dev nginx=nginx:1.17.2
deployment.apps/deploy-controller image updated
# 查看当前升级版本的状态
[root@master k8sYamlForCSDN]# kubectl rollout status deployment deploy-controller -n dev
Waiting for deployment "deploy-controller" rollout to finish: 1 out of 3 new replicas have been updated...
Waiting for deployment "deploy-controller" rollout to finish: 2 out of 3 new replicas have been updated...
Waiting for deployment "deploy-controller" rollout to finish: 1 old replicas are pending termination...
deployment "deploy-controller" successfully rolled out
# 查看升级历史记录
# 可以发现有三次版本记录,说明完成过两次升级
[root@master k8sYamlForCSDN]# kubectl rollout history deployment deploy-controller -n dev
deployment.apps/deploy-controller
REVISION CHANGE-CAUSE
1 kubectl apply --filename=deploy-controller.yaml --record=true
2 kubectl apply --filename=deploy-controller.yaml --record=true
3 kubectl apply --filename=deploy-controller.yaml --record=true
# 版本回滚
# 这里直接使用--to-revision=1回滚到了1版本(nginx), 如果省略这个选项,就是回退到上个版本,就是2版本(nginx1.17.1),目前是3版本(1.17.2)
[root@master k8sYamlForCSDN]# kubectl rollout undo deployment deploy-controller -n dev --to-revision=1
deployment.apps/deploy-controller rolled back
# 查看发现,通过nginx镜像版本可以发现到了第一版
[root@master k8sYamlForCSDN]# kubectl get deploy -n dev -o wide
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
deploy-controller 3/3 2 3 10m nginx nginx app=nginx-pod
# 查看rs,发现第三个rs中有3个pod运行
# 其实deployment之所以可是实现版本的回滚,就是通过记录下历史rs来实现的,
# 一旦想回滚到哪个版本,只需要将当前版本pod数量降为0,然后将回滚版本的pod提升为目标数量就可以了
[root@master k8sYamlForCSDN]# kubectl get rs -n dev
NAME DESIRED CURRENT READY AGE
deploy-controller-67db8df7f5 0 0 0 7m36s
deploy-controller-6f44b7b85d 0 0 0 12m
deploy-controller-7f87645cd8 3 3 3 13m
金丝雀发布
deployment控制器支持控制更新过程中的控制,如"暂停(pause)"或"继续(resume)"更新操作。
比如有一批新的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,再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。
bash
# 更新deployment的版本,并配置暂停deployment
[root@master k8sYamlForCSDN]# kubectl set image deploy deploy-controller -n dev nginx=nginx:1.17.1 && kubectl rollout pause deploy deploy-controller -n dev
deployment.apps/deploy-controller image updated
deployment.apps/deploy-controller paused
#观察更新状态
# 监控更新的过程,可以看到已经新增了一个资源,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
[root@master k8sYamlForCSDN]# kubectl get rs -n dev
NAME DESIRED CURRENT READY AGE
deploy-controller-67db8df7f5 0 0 0 19m
deploy-controller-6f44b7b85d 1 1 1 24m
deploy-controller-7f87645cd8 3 3 3 25m
[root@master k8sYamlForCSDN]# kubectl rollout status deploy deploy-controller -n dev
Waiting for deployment "deploy-controller" rollout to finish: 1 out of 3 new replicas have been updated...
# 确保更新的pod没问题了,继续更新
[root@master k8sYamlForCSDN]# kubectl rollout resume deploy deploy-controller -n dev
deployment.apps/deploy-controller resumed
# 查看最后的更新情况
[root@master k8sYamlForCSDN]# kubectl get rs -n dev -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
deploy-controller-67db8df7f5 0 0 0 23m nginx nginx:1.17.2
deploy-controller-6f44b7b85d 3 3 3 28m nginx nginx:1.17.1
deploy-controller-7f87645cd8 0 0 0 29m nginx nginx
[root@master k8sYamlForCSDN]# kubectl get pods -n dev
NAME READY STATUS RESTARTS AGE
deploy-controller-6f44b7b85d-7gfp7 1/1 Running 0 2m13s
deploy-controller-6f44b7b85d-b6n2b 1/1 Running 0 5m30s
deploy-controller-6f44b7b85d-cg4vq 1/1 Running 0 116s
删除Deployment
bash
# 删除deployment,其下的rs和pod也将被删除
[root@master k8sYamlForCSDN]# kubectl delete -f deploy-controller.yaml
deployment.apps "deploy-controller" deleted