deployment用于部署无状态应用
Deployment集成了上线部署、滚动升级、创建副本、回滚等功能
Deployment里包含并使用了ReplicaSet
Replicaset 通过改变Pod副本数量实现Pod的扩容和缩容
参考文档 
https://kubernetes.io/zh-cn/docs/concepts/workloads/controllers/deployment/
1 yaml文件
apiVersion: apps/v1 # deployment api 版本
kind: Deployment # 资源类型为 deployment
metadata: # 元信息
labels: # 标签
app: nginx-deploy # 具体的 key: value 配置形式
name: nginx-deploy # deployment 的名字
namespace: default # 所在的命名空间，默认default
spec:
replicas: 1 # 期望副本数
revisionHistoryLimit: 10 # 进行滚动更新后，保留的历史版本数
selector: # 选择器，用于找到匹配的 RS
matchLabels: # 按照标签匹配
app: nginx-deploy # 匹配的标签key/value
strategy: # 更新策略
rollingUpdate: # 滚动更新配置
maxSurge: 25% # 进行滚动更新时，更新的个数最多可以超过期望副本数的个数/比例
maxUnavailable: 25% # 进行滚动更新时，最大不可用比例更新比例，表示在所有副本数中，最多可以有多少个不更新成功
type: RollingUpdate # 更新类型，采用滚动更新
template: # pod 模板
metadata: # pod 的元信息
labels: # pod 的标签
app: nginx-deploy
spec: # pod 期望信息
containers: # pod 的容器
- image: nginx:1.7.9 # 镜像
imagePullPolicy: IfNotPresent # 拉取策略
name: nginx # 容器名称
restartPolicy: Always # 重启策略
terminationGracePeriodSeconds: 30 # 删除操作最多宽限多长时间2 pod版本升级
查看帮助
[root@k8s-master1 ~]# kubectl set image -h1, 升级前验证nginx版本
[root@k8s-master1 ~]# kubectl describe pods deploy-nginx-6d9d558bb6-f2t6r | grep Image:
Image: nginx:1.15-alpine
[root@k8s-master1 ~]# kubectl exec deploy-nginx-6d9d558bb6-f2t6r -- nginx -v
nginx version: nginx/1.15.122, 升级为1.16版
[root@k8s-master1 ~]# kubectl set image deployment deploy-nginx nginx=nginx:1.16-alpine --record
deployment.apps/deploy-nginx image updated说明:
-
deployment deploy-nginx代表名为deploy-nginx的deployment -
nginx=nginx:1.16-alpine前面的nginx为容器名 -
--record 表示会记录
容器名怎么查看?
-
kubectl describe pod pod名查看 -
kubectl edit deployment deployment名来查看容器名 -
kubectl get deployment deployment名 -o yaml来查看容器名
3, 验证
如果升级的pod数量较多，则需要一定时间，可通过下面命令查看是否已经成功
[root@k8s-master1 ~]# kubectl rollout status deployment deploy-nginx
deployment "deploy-nginx" successfully rolled out验证 pod
[root@k8s-master1 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
deploy-nginx-5f4749c8c8-nskp9 1/1 Running 0 104s 更新后,后面的id变了验证版本
[root@k8s-master1 ~]# kubectl describe pod deploy-nginx-5f4749c8c8-nskp9 |grep Image:
Image: nginx:1.16-alpine 升级为1.16了
[root@k8s-master1 ~]# kubectl exec deploy-nginx-5f4749c8c8-nskp9 -- nginx -v
nginx version: nginx/1.16.1 升级为1.16了练习: 再将nginx1升级为1.17版
[root@k8s-master1 ~]# kubectl set image deployment deploy-nginx nginx=nginx:1.17-alpine --record
deployment.apps/deploy-nginx image updated3 pod版本回退
1, 查看版本历史信息
[root@k8s-master1 ~]# kubectl rollout history deployment deploy-nginx
deployment.apps/deploy-nginx
REVISION CHANGE-CAUSE
1 <none> 原1.15版
2 kubectl set image deployment deploy-nginx nginx=nginx:1.16-alpine --record=true
3 kubectl set image deployment deploy-nginx nginx=nginx:1.17-alpine --record=true2, 定义要回退的版本（还需要执行才是真的回退版本)
[root@k8s-master1 ~]# kubectl rollout history deployment deploy-nginx --revision=1
deployment.apps/deploy-nginx with revision #1
Pod Template:
Labels: app=nginx
pod-template-hash=6c9764bb69
Containers:
nginx:
Image: nginx:1.15-alpine 可以看到这是要回退的1.15版本
Port: 80/TCP
Host Port: 0/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>3, 执行回退
[root@k8s-master1 ~]# kubectl rollout undo deployment deploy-nginx --to-revision=1
deployment.apps/deploy-nginx rolled back4, 验证
[root@k8s-master1 ~]# kubectl rollout history deployment deploy-nginx
deployment.apps/deploy-nginx
REVISION CHANGE-CAUSE
2 kubectl set image deployment deploy-nginx nginx=nginx:1.16-alpine --record=true
3 kubectl set image deployment deploy-nginx nginx=nginx:1.17-alpine --record=true
4 <none> 回到了1.15版,但revision的ID变了
[root@k8s-master1 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
deploy-nginx-6c9764bb69-zgwpj 1/1 Running 0 54s
[root@k8s-master1 ~]# kubectl describe pod deploy-nginx-6c9764bb69-zgwpj |grep Image:
Image: nginx:1.15-alpine 回到了1.15版
[root@k8s-master1 ~]# kubectl exec deploy-nginx-6c9764bb69-zgwpj -- nginx -v
nginx version: nginx/1.15.12 回到了1.15版4 副本扩容
查看帮助
[root@k8s-master1 ~]# kubectl scale -h1, 扩容为2个副本
[root@k8s-master1 ~]# kubectl scale deployment deploy-nginx --replicas=2
deployment.apps/deploy-nginx scaled2, 查看
[root@k8s-master1 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
deploy-nginx-6d9d558bb6-4c64l 1/1 Running 0 27s 10.244.159.157 k8s-master1 <none> <none>
deploy-nginx-6d9d558bb6-hkq2b 1/1 Running 0 71s 10.244.194.95 k8s-worker1 <none> <none>在两个node节点上各1个pod
3, 继续扩容(我们这里只有2个node,但是可以大于node节点数据)
[root@master ~]# kubectl scale deployment deploy-nginx --replicas=4
deployment.extensions/nginx1 scaled
[root@k8s-master1 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
deploy-nginx-6d9d558bb6-4c64l 1/1 Running 0 87s 10.244.159.157 k8s-master1 <none> <none>
deploy-nginx-6d9d558bb6-586dr 1/1 Running 0 31s 10.244.135.197 k8s-master3 <none> <none>
deploy-nginx-6d9d558bb6-hkq2b 1/1 Running 0 2m11s 10.244.194.95 k8s-worker1 <none> <none>
deploy-nginx-6d9d558bb6-kvgsc 1/1 Running 0 31s 10.244.224.13 k8s-master2 <none> <none>5 副本裁减
1, 指定副本数为1进行裁减
[root@k8s-master1 ~]# kubectl scale deployment deploy-nginx --replicas=1
deployment.apps/deploy-nginx scaled2, 查看验证
[root@k8s-master1 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
deploy-nginx-6d9d558bb6-hkq2b 1/1 Running 0 2m56s6 多副本滚动更新
1, 先扩容多点副本
[root@k8s-master1 ~]# kubectl scale deployment deploy-nginx --replicas=16
deployment.apps/deploy-nginx scaled2, 验证
[root@master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx1-7d9b8757cf-2hd48 1/1 Running 0 61s
nginx1-7d9b8757cf-5m72n 1/1 Running 0 61s
nginx1-7d9b8757cf-5w2xr 1/1 Running 0 61s
nginx1-7d9b8757cf-5wmdh 1/1 Running 0 61s
nginx1-7d9b8757cf-6szjj 1/1 Running 0 61s
nginx1-7d9b8757cf-9dgsw 1/1 Running 0 61s
nginx1-7d9b8757cf-dc7qj 1/1 Running 0 61s
nginx1-7d9b8757cf-l52pr 1/1 Running 0 61s
nginx1-7d9b8757cf-m7rt4 1/1 Running 0 26m
nginx1-7d9b8757cf-mdkj2 1/1 Running 0 61s
nginx1-7d9b8757cf-s79kp 1/1 Running 0 61s
nginx1-7d9b8757cf-shhvk 1/1 Running 0 61s
nginx1-7d9b8757cf-sv8gb 1/1 Running 0 61s
nginx1-7d9b8757cf-xbhf4 1/1 Running 0 61s
nginx1-7d9b8757cf-zgdgd 1/1 Running 0 61s
nginx1-7d9b8757cf-zzljl 1/1 Running 0 61s
nginx2-559567f789-8hstz 1/1 Running 1 114m3, 滚动更新
[root@k8s-master1 ~]# kubectl set image deployment deploy-nginx nginx=nginx:1.17-alpine --record
deployment.apps/deploy-nginx image updated4, 验证
[root@k8s-master1 ~]# kubectl rollout status deployment deploy-nginx
......
Waiting for deployment "deploy-nginx" rollout to finish: 13 of 16 updated replicas are available...
Waiting for deployment "deploy-nginx" rollout to finish: 14 of 16 updated replicas are available...
Waiting for deployment "deploy-nginx" rollout to finish: 15 of 16 updated replicas are available...
deployment "deploy-nginx" successfully rolled out7 暂停更新
由于每次对 pod template 中的信息发生修改后，都会触发更新 deployment 操作
那么此时如果频繁修改信息，就会产生多次更新，而实际上只需要执行最后一次更新即可
当出现此类情况时我们就可以暂停 deployment 的 rollout
暂停更新
通过 kubectl rollout pause deployment <name> 就可以实现暂停，直到你下次恢复后才会继续进行滚动更新
此时更新配置文件后pod不会被更新，直到恢复更新
恢复更新
kubectl rollout deploy <name>
8 删除deployment
如果使用 kubectl delete deployment deploy-nginx命令删除deployment,那么里面的pod也会被自动删除
如果使用kubectl delete po po-name 命令删除deployment管理的pod，则deployment会调度重新创建pod
