# Deployment: 声明式地升级应用 ## 使用Deployment资源升级pod 现在我们要考虑pod升级的情况了，如v1升级到v2和回滚等操作，这个场景需要改动下我们的服务。返回值里标记版本信息。 ```javascript // cat app.js const http = require('http'); const os = require('os'); console.log("Kubia server starting..."); var handler = function(request, response) { console.log("Received request from " + request.connection.remoteAddress); response.writeHead(200); response.end("This is v1 running in pod " + os.hostname() + "\n"); }; var www = http.createServer(handler); www.listen(8080); ``` 不同的版本服务已经做好了，可以直接部署使用，我们体验一下。 ```yaml # cat kubia-deployment-v1.yaml apiVersion: apps/v1 kind: Deployment # 我们这里引入了Deployment metadata: name: kubia spec: replicas: 3 selector: matchLabels: app: kubia template: metadata: name: kubia labels: app: kubia spec: containers: - image: luksa/kubia:v1 name: nodejs ``` ```yaml $ kubectl create -f kubia-deployment-v1.yaml --record deployment.apps/kubia created $ k get all NAME READY STATUS RESTARTS AGE pod/kubia-5dfcbbfcff-f5c5t 1/1 Running 0 80s pod/kubia-5dfcbbfcff-nrrxq 1/1 Running 0 80s pod/kubia-5dfcbbfcff-tthwm 1/1 Running 0 80s NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/kubia 3/3 3 3 80s NAME DESIRED CURRENT READY AGE replicaset.apps/kubia-5dfcbbfcff 3 3 3 81s ``` 观察下，Deployment自动帮我们创建了rs/pod这些。 ```yaml $ kubectl get deployment kubia NAME READY UP-TO-DATE AVAILABLE AGE kubia 3/3 3 3 53s $ kubectl describe deployment kubia Name: kubia Namespace: liuzongxian ... ... ... ... #下面指令表示发版完成了 ：） $ kubectl rollout status deployment kubia 127 ↵ deployment "kubia" successfully rolled out ``` {% hint style="success" %} Deployment 是我们常用的发版方式，且--record记录发版历史，这样我们能够回滚很便利 {% endhint %} 好像deployment没带来什么好处，下面看看升级、回滚 ## 执行滚动升级 为了演示v1升级v2过程，我们做一下服务监控工作。这次连通服务service一起创建出来。 ```yaml # cat kubia-deployment-and-service-v1.yaml 130 ↵ apiVersion: apps/v1 kind: Deployment metadata: name: kubia spec: replicas: 3 selector: matchLabels: app: kubia template: metadata: name: kubia labels: app: kubia spec: containers: - image: luksa/kubia:v1 name: nodejs --- apiVersion: v1 kind: Service metadata: name: kubia spec: type: LoadBalancer selector: app: kubia ports: - port: 80 targetPort: 8080 ``` ```yaml #清理掉前面的deployment $ k delete deployment.apps/kubia deployment.apps "kubia" deleted ``` ```yaml #使用带有服务的deployment部署 $ k create -f kubia-deployment-and-service-v1.yaml deployment.apps/kubia created service/kubia created #设置服务滚动升级的速度，就是不要太快了 $ kubectl patch deployment kubia -p '{"spec": {"minReadySeconds": 10}}' 130 ↵ deployment.extensions/kubia patched ``` 服务部署好后，因为有负载均衡器地址，可以访问到服务 {% hint style="info" %} 还记得获取LB的地址么，使用k get svc试试 {% endhint %} ```yaml #打开服务监控脚本，不停的访问服务，会显示版本号 while true; do curl http://<130.21.109.222替换自己的>; done ``` {% hint style="danger" %} 如果LB申请不下来，可以使用busybox内网测试，见： {% endhint %} ```yaml $ kubectl run busybox --rm -i --tty --image busybox -- sh $ while true; do wget -O- http://<172.22.2.107替换自己的>; sleep 1; done ``` 执行升级操作，这里是将deployment中的image由v1改为了v2 ```yaml $ kubectl set image deployment kubia nodejs=luksa/kubia:v2 deployment.extensions/kubia image updated ``` 我们观察到curl返回结果由全部是v1，开始陆续出现了v2，直至全都是v2 ```yaml This is v1 running in pod kubia-5dfcbbfcff-b2445 This is v1 running in pod kubia-5dfcbbfcff-78m6h This is v1 running in pod kubia-5dfcbbfcff-pvwdj This is v2 running in pod kubia-7c699f58dd-b2fng This is v2 running in pod kubia-7c699f58dd-b2fng This is v1 running in pod kubia-5dfcbbfcff-b2445 This is v1 running in pod kubia-5dfcbbfcff-b2445 This is v2 running in pod kubia-7c699f58dd-b2fng This is v1 running in pod kubia-5dfcbbfcff-pvwdj ``` 这样升级就完成了，一个指令就陆续的完成了部署，是不是很简单呢！ ## 回滚pod到上个版本 我们准备了一个有错误的版本v3，它不能正常工作，在从v2到v3升级时看看发生什么 ```yaml $ kubectl set image deployment kubia nodejs=luksa/kubia:v3 deployment.extensions/kubia image updated ``` 能看到错误的版本出现了 ```yaml This is v2 running in pod kubia-7c699f58dd-b2fng This is v2 running in pod kubia-7c699f58dd-c9wpf This is v3 running in pod kubia-5c98f77977-n8bk4 This is v2 running in pod kubia-7c699f58dd-c9wpf This is v2 running in pod kubia-7c699f58dd-np59f This is v2 running in pod kubia-7c699f58dd-b2fng Some internal error has occurred! This is pod kubia-5c98f77977-n8bk4 This is v2 running in pod kubia-7c699f58dd-c9wpf This is v2 running in pod kubia-7c699f58dd-np59f Some internal error has occurred! This is pod kubia-5c98f77977-n8bk4 This is v2 running in pod kubia-7c699f58dd-np59f This is v2 running in pod kubia-7c699f58dd-c9wpf This is v2 running in pod kubia-7c699f58dd-np59f ``` 此时我们做一下回滚操作 ```yaml $ kubectl rollout undo deployment kubia deployment.extensions/kubia rolled back ``` 然后看到服务回滚到v2了，恢复正常 ```yaml This is v2 running in pod kubia-7c699f58dd-lxc4w This is v2 running in pod kubia-7c699f58dd-6mq49 Some internal error has occurred! This is pod kubia-5c98f77977-n8bk4 This is v2 running in pod kubia-7c699f58dd-d96vg This is v2 running in pod kubia-7c699f58dd-d96vg This is v2 running in pod kubia-7c699f58dd-d96vg This is v2 running in pod kubia-7c699f58dd-6mq49 ``` 做到这里是不是觉得升级与回滚都特别便利了呢？我们看看它是怎么做到的 ```yaml $ k get all NAME READY STATUS RESTARTS AGE pod/kubia-5c98f77977-hn48c 1/1 Running 0 8m17s pod/kubia-5c98f77977-n8bk4 1/1 Running 0 8m33s pod/kubia-5c98f77977-vdh69 1/1 Running 0 8m1s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubia LoadBalancer 172.22.11.131 47.52.107.163 80:32456/TCP 32m NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/kubia 3/3 3 3 32m NAME DESIRED CURRENT READY AGE replicaset.apps/kubia-5c98f77977 3 3 3 8m35s replicaset.apps/kubia-5dfcbbfcff 0 0 0 32m replicaset.apps/kubia-7c699f58dd 0 0 0 28m ``` 还记得--record参数么，它帮我们记录了发版历史，从replicaset能看出来已经有了三个版本，所以在回滚时，它能知道我们回滚到哪个历史版本 {% hint style="info" %} deployment能够控制升级速度、出错暂停升级、回滚到指定版本等等，非常强大，大家可以多做做练习 {% endhint %} 我们回滚到最初的版本v1玩一下 ```yaml $ kubectl rollout history deployment kubia deployment.extensions/kubia REVISION CHANGE-CAUSE 1 3 4 $ kubectl rollout undo deployment kubia --to-revision=1 deployment.extensions/kubia rolled back ``` 回到版本v1了 ```yaml This is v1 running in pod kubia-5dfcbbfcff-z86v5 This is v1 running in pod kubia-5dfcbbfcff-pztrs This is v2 running in pod kubia-7c699f58dd-lxc4w This is v1 running in pod kubia-5dfcbbfcff-qcvjx This is v1 running in pod kubia-5dfcbbfcff-pztrs This is v1 running in pod kubia-5dfcbbfcff-qcvjx This is v1 running in pod kubia-5dfcbbfcff-z86v5 This is v1 running in pod kubia-5dfcbbfcff-pztrs This is v1 running in pod kubia-5dfcbbfcff-qcvjx ``` So！Deployment是管理发版的利器。做完这里，你已经完成了绝大部分的容器管理内容了！ {% hint style="info" %} 最后，在做下一节前，注意清理资源 {% endhint %} ## 思考题 > * 记录发版历史有个重要参数，是什么？怎么从v2回滚到v1版本呢？ --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://doc.spotmaxtech.com/she-qu-huo-dong/kubernetes-workshop/additional/deployment-sheng-ming-shi-di-sheng-ji-ying-yong.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.