1、Pod介绍控制器
在kubernetes中，按照pod可分为两类：
● :kubernetes直接创建pod，这种pod删除后不会重建
● ：由控制器创建pod，这种pod删除后，将自动重建
Pod控制器是管理pod使用了中间层pod在控制器之后，我们只需要告诉你pod控制器，你想要多少？pod可以，它会创造出符合条件的pod确保每一个pod如果处于用户期望的状态，pod如果在运行中出现故障，控制器将根据指定的策略重启或重建pod。
在kubernetes有很多种类型的pod每个控制器都有自己合适的场景，常见的有以下几点:
● ReplicationController：比较原始的pod控制器已被废弃，由ReplicaSet替代
● ReplicaSet：解证指定数量pod并支持运行pod数量变化，镜像版本变化
● Deployment：通过控制ReplicaSet来控制pod，并支持滚动升级、版本回归
● Deployment：通过控制ReplicaSet来控制pod，并支持滚动升级、版本回归
● Horizontal Pod Autoscaler：可根据集群负载自动调整Pod削峰填谷实现数量
● DaemonSet：指定集群Node一个副本通常用于保护过程任务
● Job：它创造的pod完成任务后立即退出执行一次性任务
● Cronjob：它创建的pod定期执行，用于执行定期任务
● StatefulSet：管理有状态应用
2、ReplicasSet
ReplicaSet保证一定数量的主要作用是保证一定数量pod能够正常运行，它将继续监控这些pod一旦pod发生故障，就会重启或重建。同时它还支持对pod扩缩容量和升级版本镜像。
1.1 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 # 命名空间 labels: # 标签 controller: rs spec: # 详情描述 replicas:3 # 副本数量 selector: # 选择器，通过他指定控制器管理什么pod matchLabels: # labels的匹配规则 app:nginx-pod matchExpressions: # Expressions匹配规则 - {key: app, operator: In, values: [nginx-opd]} template: # 当副本数量不足时，模板，根据以下模板创建模板pod副本 metadata: labels: app: nginx-pod spec: containers: - name: nginx image: nginx:1.17.1 ports: - containerPort: 80apiVersion: apps/v1 # 版本号 kind: ReplicaSet # 类型 metadata: name: pc-replicaset namespace: dev spec: replicas: 3 selector: matchLabels: app:nginx-pod template: metadata: labels: app: nginx-pod spec: containers: - name: nginx image: nginx:1.17.1 # 创建rs并查看 [root@master ~]# kubectl create -f pc-replicaset.yaml replicaset.apps/pc-relicaset created [root@master ~]# kubectl get rs -n dev -o wide NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR pc-replicaset 3 3 3 111s nginx nginx:1.17.1 app=nginx-pod [root@master ~]# kubectl get pod -n dev NAME READY STATUS RESTARTS AGE pc-relicaset-cvccs 1/1 Running 0 3m53s pc-relicaset-r6vqt 1/1 Running 0 3m53s pc-relicaset-srkjz 1/1 Running 0 3m53s 1.2
再看看rs的：可直接使用edit编辑命令
# 编辑rs副本数，修改spec:replicas： 6 [root@master ~]# kubectl edit rs pc-replicaset -n dev replicaset.apps/pc-replicaset edited [root@master ~]# kubectl get pod -n dev NAME READY STATUS RESTARTS AGE pc-replicaset-2ql9q 1/1 Running 0 4m44s pc-replicaset-5jsfj 1/1 Running 0 12s pc-replicaset-5n998 1/1 Running 0 12s pc-replicaset-mzs8p 1/1 Running 0 4m44s pc-replicaset-w5x9x 1/1 Running 0 12s pc-replicaset-zqrbg 1/1 Running 0 4m44s 当然，命令也可以直接实现：
[root@master ~]# kubectl scale rs pc-replicaset --replicas=3 -n dev replicaset.apps/pc-replicaset scaled [root@master ~]# kubectl get pod -n dev NAME READY STATUS RESTARTS AGE pc-replicaset-2ql9q 1/1 Running 0 6m27s pc-replicaset-mzs8p 1/1 Running 0 6m27s pc-replicaset-zqrbg 1/1 Running 0 6m27s# 使用edit编辑yaml文件进行修改
[root@master ~]# kubectl edit rs pc-replicaset -n dev
replicaset.apps/pc-replicaset edited
[root@master ~]# kubectl get rs -n dev -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
pc-replicaset 3 3 3 11m nginx nginx:1.17.2 app=nginx-pod
# 使用命令直接进行修改
[root@master ~]# kubectl set image rs pc-replicaset nginx=nginx:1.17.3 -n dev
replicaset.apps/pc-replicaset image updated
[root@master ~]# kubectl get rs -n dev -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
pc-replicaset 3 3 3 14m nginx nginx:1.17.3 app=nginx-pod1.4 删除ReplicaSet
使用delete命令会删除rs以及他所管理的pod
# 在Kubernetes删除RS之前，会将rs的replicasclear调整为0，等待所有pod被删除后，再执行Rs对象的删除
# 如果希望仅仅删除RS对象，保留Pod可以使用kubectl delete命令时添加--cascade=falsexuanx（不推荐）
# [root@master ~]# kubectl delete rs pc-replicaset -n dev --cascade=false
[root@master ~]# kubectl delete rs pc-replicaset -n dev
replicaset.apps "pc-replicaset" deleted
[root@master ~]# kubectl get pod -n dev -o wide
No resources found in dev namespace.
2、Deployment(Deploy)
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。值得一提的是，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
● 支持版本滚动更新和版本回退
2.1 Deployment的资源清单文件
apiVersion: apps/v1 # 版本号
kind: Deployment # 类型
metadata: # 元数据
name: # rs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
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:1.17.1
ports:
- containerPort: 802.2 创建deployment
创建pc-deployment.yaml文件
apiVersion: apps/v1
kind: Deployment
metadata:
name: pc-deployment
namespace: dev
spec:
replicas: 3
selector:
matchLabels:
app: nginx-pod
template:
metadata:
labels:
app: nginx-pod
spec:
containers:
- name: nginx
image: nginx:1.17.1
# 创建deployment
[root@master ~]# kubectl create -f pc-deployment.yaml
deployment.apps/pc-deployment 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 ~]# kubectl get deploy -n dev -o wide
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
pc-deployment 3/3 3 3 63s nginx nginx:1.17.1 app=nginx-pod
# 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 ~]# kubectl get rs -n dev -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
pc-deployment-6f7f65b46d 3 3 3 2m48s nginx nginx:1.17.1 app=nginx-pod,pod-template-hash=6f7f65b46d
# 再来查看一下pod
[root@master ~]# kubectl get pod -n dev
NAME READY STATUS RESTARTS AGE
pc-deployment-6f7f65b46d-5hbdj 1/1 Running 0 3m36s
pc-deployment-6f7f65b46d-6lzhr 1/1 Running 0 3m36s
pc-deployment-6f7f65b46d-8bhqc 1/1 Running 0 3m36s
2.3 扩缩容
# 变更副本数量为5个
[root@master ~]# kubectl scale deploy pc-deployment --replicas=5 -n dev
deployment.apps/pc-deployment scaled
# 查看deployment
[root@master ~]# kubectl get deploy -n dev -o wide
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
pc-deployment 5/5 5 5 10m nginx nginx:1.17.1 app=nginx-pod
# 或者通过edit编辑yaml文件进行修改
[root@master ~]# kubectl edit deploy pc-deployment -n dev
deployment.apps/pc-deployment edited
[root@master ~]# kubectl get deploy -n dev -o wide
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
pc-deployment 3/3 3 3 31m nginx nginx:1.17.1 app=nginx-pod2.4 镜像更新
deployment支持两种更新策略:`重建更新`和`滚动更新（默认）`,可以通过`strategy`指定策略类型,支持两个属性:
：指定新的Pod替换旧的Pod的策略， 支持两个属性：
：指定策略类型，支持两种策略
：在创建出新的Pod之前会先杀掉所有已存在的Pod
：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
rollingUpdate：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%
1） 编辑pc-deployment.yaml,在spec节点下添加更新策略
apiVersion: apps/v1
kind: Deployment
metadata:
name: pc-deployment
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:1.17.1
# 应用yaml文件进行更新
[root@master ~]# kubectl apply -f pc-deployment.yaml
deployment.apps/pc-deployment configured
# 另一个窗口进行监听
[root@master ~]# kubectl get pod -n dev -w
NAME READY STATUS RESTARTS AGE
pc-deployment-6f7f65b46d-5hbdj 1/1 Running 0 42m
pc-deployment-6f7f65b46d-8bhqc 1/1 Running 0 42m
pc-deployment-6f7f65b46d-f4jhb 1/1 Running 0 34m
# 镜像进行更新
[root@master ~]# kubectl set image deploy pc-deployment nginx=nginx:1.17.2 -n dev
deployment.apps/pc-deployment image updated
# 查看pod状态信息
pc-deployment-6f7f65b46d-8bhqc 1/1 Terminating 0 43m
pc-deployment-6f7f65b46d-f4jhb 1/1 Terminating 0 36m
pc-deployment-6f7f65b46d-5hbdj 1/1 Terminating 0 43m
pc-deployment-6f7f65b46d-8bhqc 1/1 Terminating 0 43m
pc-deployment-6f7f65b46d-5hbdj 1/1 Terminating 0 43m
pc-deployment-6f7f65b46d-f4jhb 1/1 Terminating 0 36m
pc-deployment-6f7f65b46d-8bhqc 0/1 Terminating 0 43m
pc-deployment-6f7f65b46d-8bhqc 0/1 Terminating 0 43m
pc-deployment-6f7f65b46d-8bhqc 0/1 Terminating 0 43m
pc-deployment-6f7f65b46d-5hbdj 0/1 Terminating 0 43m
pc-deployment-6f7f65b46d-5hbdj 0/1 Terminating 0 43m
pc-deployment-6f7f65b46d-5hbdj 0/1 Terminating 0 43m
pc-deployment-6f7f65b46d-f4jhb 0/1 Terminating 0 36m
pc-deployment-6f7f65b46d-f4jhb 0/1 Terminating 0 36m
pc-deployment-6f7f65b46d-f4jhb 0/1 Terminating 0 36m
pc-deployment-86f4996797-n5xcq 0/1 Pending 0 0s
pc-deployment-86f4996797-n5xcq 0/1 Pending 0 0s
pc-deployment-86f4996797-n5xcq 0/1 ContainerCreating 0 0s
pc-deployment-86f4996797-n5xcq 0/1 ContainerCreating 0 1s
pc-deployment-86f4996797-n5xcq 1/1 Running 0 10s
pc-deployment-86f4996797-7l25t 0/1 Pending 0 0s
pc-deployment-86f4996797-gl6bg 0/1 Pending 0 0s
pc-deployment-86f4996797-7l25t 0/1 Pending 0 0s
pc-deployment-86f4996797-gl6bg 0/1 Pending 0 0s
pc-deployment-86f4996797-7l25t 0/1 ContainerCreating 0 0s
pc-deployment-86f4996797-gl6bg 0/1 ContainerCreating 0 0s
pc-deployment-86f4996797-7l25t 0/1 ContainerCreating 0 1s
pc-deployment-86f4996797-gl6bg 0/1 ContainerCreating 0 1s
pc-deployment-86f4996797-gl6bg 1/1 Running 0 1s
pc-deployment-86f4996797-7l25t 1/1 Running 0 26s 1）编辑pc-deployment.yaml,在spec节点下添加更新策略
spec:
strategy: # 策略
type: RollingUpdate # 滚动更新策略
rollingUpdate:
maxSurge: 25%
maxUnavailable: 25%2）更新并进行监听：
[root@master ~]# kubectl apply -f pc-deployment.yaml
deployment.apps/pc-deployment configured
pc-deployment-6f7f65b46d-4b62m 0/1 Pending 0 0s
pc-deployment-6f7f65b46d-4b62m 0/1 Pending 0 0s
pc-deployment-6f7f65b46d-4b62m 0/1 ContainerCreating 0 0s
pc-deployment-6f7f65b46d-4b62m 0/1 ContainerCreating 0 1s
pc-deployment-6f7f65b46d-4b62m 1/1 Running 0 2s
pc-deployment-86f4996797-n5xcq 1/1 Terminating 0 10m
pc-deployment-6f7f65b46d-bc2m4 0/1 Pending 0 0s
pc-deployment-6f7f65b46d-bc2m4 0/1 Pending 0 0s
pc-deployment-6f7f65b46d-bc2m4 0/1 ContainerCreating 0 0s
pc-deployment-86f4996797-n5xcq 1/1 Terminating 0 10m
pc-deployment-6f7f65b46d-bc2m4 0/1 ContainerCreating 0 1s
pc-deployment-86f4996797-n5xcq 0/1 Terminating 0 10m
pc-deployment-86f4996797-n5xcq 0/1 Terminating 0 10m
pc-deployment-86f4996797-n5xcq 0/1 Terminating 0 10m
pc-deployment-6f7f65b46d-bc2m4 1/1 Running 0 3s
pc-deployment-86f4996797-gl6bg 1/1 Terminating 0 10m
pc-deployment-6f7f65b46d-n2fgd 0/1 Pending 0 0s
pc-deployment-6f7f65b46d-n2fgd 0/1 Pending 0 0s
pc-deployment-6f7f65b46d-n2fgd 0/1 ContainerCreating 0 0s
pc-deployment-86f4996797-gl6bg 1/1 Terminating 0 10m
pc-deployment-6f7f65b46d-n2fgd 0/1 ContainerCreating 0 0s
pc-deployment-86f4996797-gl6bg 0/1 Terminating 0 10m
pc-deployment-86f4996797-gl6bg 0/1 Terminating 0 10m
pc-deployment-86f4996797-gl6bg 0/1 Terminating 0 10m
pc-deployment-6f7f65b46d-n2fgd 1/1 Running 0 2s
pc-deployment-86f4996797-7l25t 1/1 Terminating 0 10m
pc-deployment-86f4996797-7l25t 1/1 Terminating 0 10m
pc-deployment-86f4996797-7l25t 0/1 Terminating 0 10m
pc-deployment-86f4996797-7l25t 0/1 Terminating 0 10m
pc-deployment-86f4996797-7l25t 0/1 Terminating 0 10m先启动，在更新。。。
2.5 版本回退
删除之前创建的deployment
[root@master ~]# kubectl delete -f pc-deployment.yaml
deployment.apps "pc-deployment" deleted
# 重新创建deployment 并记录deployment的更新过程
[root@master ~]# kubectl delete -f pc-deployment.yaml
deployment.apps "pc-deployment" deleted
#记录
[root@master ~]# kubectl create -f pc-deployment.yaml --record
deployment.apps/pc-deployment created
#进行deployment镜像更新
[root@master ~]# kubectl set image deploy pc-deployment nginx=nginx:1.17.2 -n dev
deployment.apps/pc-deployment image updated
# 在监听窗口发现创建了一个新的rs
[root@master ~]# kubectl get rs -n dev
NAME DESIRED CURRENT READY AGE
pc-deployment-6f7f65b46d 0 0 0 5h43m
pc-deployment-86f4996797 3 3 3 83s
# 版本回退回退到之前的rs上，删一个pod添加一个poddeployment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 ： 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）
#现看看deployment升级是否成功？
[root@master ~]# kubectl rollout status deploy pc-deployment -n dev
deployment "pc-deployment" successfully rolled out
# 查看升级历史
[root@master ~]# kubectl rollout history deploy pc-deployment -n dev
deployment.apps/pc-deployment
REVISION CHANGE-CAUSE
1 kubectl create --filename=pc-deployment.yaml --record=true
2 kubectl create --filename=pc-deployment.yaml --record=true
# 再升级一次
[root@master ~]# kubectl set image deploy pc-deployment nginx=nginx:1.17.3 -n dev
deployment.apps/pc-deployment image updated
# 查看升级历史
[root@master ~]# kubectl rollout history deploy pc-deployment -n dev
deployment.apps/pc-deployment
REVISION CHANGE-CAUSE
1 kubectl create --filename=pc-deployment.yaml --record=true
2 kubectl create --filename=pc-deployment.yaml --record=true
3 kubectl create --filename=pc-deployment.yaml --record=true
# 版本回滚
# 这里直接使用--to-revision=1回滚到了1版本， 如果省略这个选项，就是回退到上个版本，就是2版本
# 现查看一下当前deployment的镜像版本：nginx1.17.3
[root@master ~]# kubectl get deploy -n dev -o wide
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
pc-deployment 3/3 3 3 5h55m nginx nginx:1.17.3 app=nginx-pod
# 回退到1版本(nginx:1.17.1)
[root@master ~]# kubectl rollout undo deploy pc-deployment --to-revision=1 -n dev
deployment.apps/pc-deployment rolled back
# 查看rs 第一个deployment中有东西
[root@master ~]# kubectl get rs -n dev
NAME DESIRED CURRENT READY AGE
pc-deployment-6f7f65b46d 3 3 3 5h58m
pc-deployment-79f7d88458 0 0 0 5m50s
pc-deployment-86f4996797 0 0 0 16m2.6 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。
# 更新deployment的版本，并配置暂停deployment
[root@master ~]# kubectl get rs -n dev
NAME DESIRED CURRENT READY AGE
pc-deployment-6f7f65b46d 3 3 3 6h3m
pc-deployment-79f7d88458 0 0 0 11m
pc-deployment-86f4996797 0 0 0 21m
pc-deployment-cf7c57879 1 1 1 18s
# 老版本依旧在运行，新版本已经创建出了一个pod 查看状态
[root@master ~]# kubectl rollout status deploy pc-deployment -n dev
Waiting for deployment "pc-deployment" rollout to finish: 1 out of 3 new replicas have been updated...
# 显示在等待更新状态 发现没有问题之后继续更新
[root@master ~]# kubectl rollout resume deploy pc-deployment -n dev
deployment.apps/pc-deployment resumed
# 查看rs状态
[root@master ~]# kubectl get rs -n dev -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
pc-deployment-6f7f65b46d 0 0 0 6h8m nginx nginx:1.17.1 app=nginx-pod,pod-template-hash=6f7f65b46d
pc-deployment-79f7d88458 0 0 0 15m nginx nginx:1.17.3 app=nginx-pod,pod-template-hash=79f7d88458
pc-deployment-86f4996797 0 0 0 26m nginx nginx:1.17.2 app=nginx-pod,pod-template-hash=86f4996797
pc-deployment-cf7c57879 3 3 3 4m45s nginx nginx:1.17.4 app=nginx-pod,pod-template-hash=cf7c57879