deployment 可以简写为deploy

Deployment 相比与replicaSet 多出一些功能设定。

Deployment VS replicaSet

PS: 对比版本 1.18.0

项目	Fields	Deployment	replicaSet
apiVersion		apps/v1	apps/v1
metadata		两者一致	两者一致
kind		Deployment	replicaSet
spec	minReadySeconds	√	√
	paused	√
	progressDeadlineSeconds	√
	replicas	√	√
	revisionHistoryLimit	√
	selector	√	√
	strategy	√
	template	√	√

测试随笔

[root@test2 ~]# kubectl get deploy
NAME           READY   UP-TO-DATE   AVAILABLE   AGE
myapp-deploy   2/2     2            2           23s
[root@test2 ~]# kubectl get rs
NAME                      DESIRED   CURRENT   READY   AGE
myapp-deploy-65fb6c8459   2         2         2       33s
[root@test2 ~]# kubectl get pods
NAME                            READY   STATUS    RESTARTS   AGE
myapp-deploy-65fb6c8459-8ncqg   1/1     Running   0          44s
myapp-deploy-65fb6c8459-sx72t   1/1     Running   0          44s

[root@test ~]# kubectl patch deploy/myapp-deploy -p '{"spec":{"replicas::5}}'
Error from server (BadRequest): unexpected EOF    #看清格式

[root@test ~]# kubectl patch deploy/myapp-deploy -p '{"deploy":{"strategy":{"rollingUpdate":{"maxSurge":1,"maxUnavailiable":1}}}}'
deployment.apps/myapp-deploy patched (no change) #为甚么会有no change ？ 用patch就是死活不更新。请各位评论告知我原因，谢谢

Deploy中重要的字段 spec.strategy

• type : Can be “Recreate” or “RollingUpdate”. Default is RollingUpdate.滚动发布
• rollingUpdate: 仅在type为RollingUpdate时有效
• rollingUpdate.maxSurge 最大可超期望的节点数，百分比 10% 或者绝对数值 5
• rollingUpdate.maxUnavailable 最大不可用节点数，百分比或者绝对数值

灰度发布、滚动发布和蓝绿发布

**假设replicaSet=10 maxSurge &maxUnavailable不能同时为0 **

类型	描述	maxSurge	maxUnavailable
灰度发布	又名金丝雀发布。先极个别更新，通过后再一次全部更新	1或10%	视对服务可用度的需求
滚动发布	（部分更新，投入使用）* 直到全部更新完成	1<x<（具体看更新的粒度）	视对服务可用度的需求
蓝绿发布	新旧版共存，靠切换流量完成更新	10	0

知识有限，欢迎评论指正，感谢。

Deploy的灰度发布初体验

• maxSurge=1 maxUnavailable=0 rs=5

[root@test2 ~]# kubectl set image deploy myapp-deploy myapp=ikubernetes/myapp:v2 && kubectl rollout pause deploy myapp-deploy 
deployment.apps/myapp-deploy image updated
deployment.apps/myapp-deploy paused
[root@test ~]# kubectl get pods -w
NAME                            READY   STATUS    RESTARTS   AGE
myapp-deploy-65fb6c8459-4gwnl   1/1     Running   0          12m
myapp-deploy-65fb6c8459-4jkw9   1/1     Running   0          12m
myapp-deploy-65fb6c8459-mrcqz   1/1     Running   0          12m
myapp-deploy-65fb6c8459-pqfxd   1/1     Running   0          12m
myapp-deploy-65fb6c8459-z9psx   1/1     Running   0          12m
myapp-deploy-559ff5c66-vm6hl    0/1     Pending   0          0s
myapp-deploy-559ff5c66-vm6hl    0/1     Pending   0          0s
myapp-deploy-559ff5c66-vm6hl    0/1     ContainerCreating   0          0s
myapp-deploy-559ff5c66-vm6hl    1/1     Running             0          1s
[root@test2 ~]#  kubectl rollout resume deploy myapp-deploy     #测试ok 继续更新
deployment.apps/myapp-deploy resumed
[root@test2 ~]# kubectl get rs -o wide    #更新完成后可以看到两版rs 
NAME                      DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES                 SELECTOR
myapp-deploy-559ff5c66    5         5         5       7m28s   myapp        ikubernetes/myapp:v2   app=myapp,pod-template-hash=559ff5c66,release=canary
myapp-deploy-65fb6c8459   0         0         0       25m     myapp        ikubernetes/myapp:v1   app=myapp,pod-template-hash=65fb6c8459,release=canary

Deploy的滚动发布

• maxSurge=3 maxUnavailable=0 rs=5
• 其余与命令与灰度发布一致。 此例就是新版pod创建到maxSurge数值，然后停3个旧的。这样就是第一批的更新。

[root@test2 ~]# kubectl get rs -o wide -w
NAME                      DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES                 SELECTOR
myapp-deploy-559ff5c66    5         5         5       77s     myapp        ikubernetes/myapp:v2   app=myapp,pod-template-hash=559ff5c66,release=canary
myapp-deploy-65fb6c8459   0         0         0       11m     myapp        ikubernetes/myapp:v1   app=myapp,pod-template-hash=65fb6c8459,release=canary
#以上是原来的2个rs，命令执行以后，v3版的rs出现（下面这行）
myapp-deploy-6b9865d969   3         0         0       0s      myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
#没太明白为啥还要打印一行，可能是在停v2 rs中的pod?   请大神评论指教，感谢
myapp-deploy-6b9865d969   3         0         0       0s      myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
#3个新版pod被创建，陆续变成ready状态
myapp-deploy-6b9865d969   3         3         0       0s      myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   3         3         1       2s      myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   3         3         2       2s      myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   3         3         3       2s      myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary

第二批？？？这算是手动更新？？ 恢复然后再暂停？ 从结果看是的

[root@test ~]# kubectl rollout resume deploy/myapp-deploy && kubectl rollout pause deploy/myapp-deploy  
deployment.apps/myapp-deploy resumed
deployment.apps/myapp-deploy paused
[root@test ~]# kubectl get deploy
NAME           READY   UP-TO-DATE   AVAILABLE   AGE
myapp-deploy   8/5     6            8           30m

#另外一台 kubectl get rs -o wide -w 新增的内容
NAME                      DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES                 SELECTOR
#rs v2期望节点变成2个, 后续需要减少2个
myapp-deploy-559ff5c66    2         5         5       13m     myapp        ikubernetes/myapp:v2   app=myapp,pod-template-hash=559ff5c66,release=canary
#rs v3期望节点变成5个，后续需要增加2个
myapp-deploy-6b9865d969   5         3         3       12m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
#rs v2 运行的pod变成 2个
myapp-deploy-559ff5c66    2         5         5       13m     myapp        ikubernetes/myapp:v2   app=myapp,pod-template-hash=559ff5c66,release=canary
myapp-deploy-559ff5c66    2         2         2       13m     myapp        ikubernetes/myapp:v2   app=myapp,pod-template-hash=559ff5c66,release=canary
#rs v3 期望变成6， 随后v3的pod增至6 并且逐步变成ready状态，为什么是6？ 就因为maxSurge=3, 可以任性咯？ 结果对就好，无所谓了
myapp-deploy-6b9865d969   5         3         3       12m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   6         3         3       12m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   6         5         3       12m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   6         5         3       12m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   6         6         3       12m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   6         6         4       12m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   6         6         5       12m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-6b9865d969   6         6         6       12m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary

第三次运行与第二次相同的命令， 也可以不再加上pause

NAME                      DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES                 SELECTOR
#rs v3 期望=5 ， 减少1pod ； v2 期望变成0，停止剩余pod
myapp-deploy-6b9865d969   5         6         6       20m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-559ff5c66    0         2         2       21m     myapp        ikubernetes/myapp:v2   app=myapp,pod-template-hash=559ff5c66,release=canary
myapp-deploy-6b9865d969   5         6         6       20m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary
myapp-deploy-559ff5c66    0         2         2       21m     myapp        ikubernetes/myapp:v2   app=myapp,pod-template-hash=559ff5c66,release=canary
myapp-deploy-559ff5c66    0         0         0       21m     myapp        ikubernetes/myapp:v2   app=myapp,pod-template-hash=559ff5c66,release=canary
myapp-deploy-6b9865d969   5         5         5       20m     myapp        ikubernetes/myapp:v3   app=myapp,pod-template-hash=6b9865d969,release=canary

Deploy的蓝绿发布

• maxSurge=5 maxUnavailable=0 rs=5
• 不赘述了

Deploy 退版初体验

[root@test2 ~]# kubectl rollout history deploy/myapp-deploy  #检查历史版本
deployment.apps/myapp-deploy
REVISION  CHANGE-CAUSE
1         <none>
2         <none>

[root@test2 ~]# kubectl rollout undo deploy/myapp-deploy  # 退版，默认退回上一版，也可指定revision的值
deployment.apps/myapp-deploy rolled back
[root@test2 ~]# kubectl rollout history deploy/myapp-deploy #检查历史版本，版1消失
deployment.apps/myapp-deploy
REVISION  CHANGE-CAUSE
2         <none>
3         <none>