第4章：应用程序生命周期管理
在 Kubernetes部署应用程序流程
1 制作镜像 2 控制器管理Pod 3 暴露应用 4 对外发布应用 5 日志/监控
镜像分类：
1、基础镜像，例如centos、ubuntu
2、环境镜像，例如jdk、python、go
3、项目镜像，基于环境镜像，将项目打包里面
为什么自己构建镜像？
1、特殊环境配置
2、容易故障排查
3、标准化
4、更安全一些
1、准备编译环境
yum install java-1.8.0-openjdk maven -y
2、编译构建
mvn clean package -D maven.skip.test=true
修改源Maven编译的时候快一些： vi /etc/maven/settings.xml <mirrors> <mirror> <id>central</id> <mirrorOf>central</mirrorOf> <name>aliyun maven</name> <url>https://maven.aliyun.com/repository/public</url> </mirror> </mirrors>
构建镜像
docker build -t java-demo:v1 . docker tag java-demo:v1 lizhenliang/java-demo:v1 # 打标签 docker push lizhenliang/java-demo:v1 # 发布容容器
- 推送到公共镜像仓库 - 搭建一个harbor私有镜像仓库 - 导入导出： docker save java-demo:v1 > java-demo.tar docker load < java-demo.tar
[root@k8s-m1 tomcat-java-demo-master]# ls db Dockerfile LICENSE pom.xml README.md src target [root@k8s-m1 tomcat-java-demo-master]# cat Dockerfile FROM tomcat:8 LABEL maintainer www.ctnrs.com RUN rm -rf /usr/local/tomcat/webapps/* ADD target/*.war /usr/local/tomcat/webapps/ROOT.war
demo地址：
github.com/lizhenliang/tomcat-java-demo
使用 Deployment部署Java应用
0、制作镜像 准备项目代码->编译构建->将产岀的war包打包到镜像中->推送到镜像仓库
1、使用 Deployment控制器部署镜像 kubectl create deployment web --image=lizhenliang/java-demo
2、使用 Service发布Pod kubectl expose deployment web --port=80 --type=NodePort --target-port=8080 --name=web kubectl get service
命令行部署
[root@k8s-m1 tomcat-java-demo-master]# kubectl create deployment web --image=lizhenliang/java-demo
deployment.apps/web created
[root@k8s-m1 tomcat-java-demo-master]# kubectl get deploy,pods
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx 1/1 1 1 11d
deployment.apps/web 1/1 1 1 57s
NAME READY STATUS RESTARTS AGE
pod/nginx-f89759699-qjjjb 1/1 Running 1 5d8h
pod/web-6b9c78c94f-vvtks 1/1 Running 0 57s
[root@k8s-m1 tomcat-java-demo-master]# kubectl expose deployment web --port=80 --type=NodePort --target-port=8080 --name=web
service/web exposed
[root@k8s-m1 tomcat-java-demo-master]# kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 11d
nginx NodePort 10.96.231.76 <none> 80:31473/TCP 11d
web NodePort 10.109.105.181 <none> 80:32116/TCP 8s
[root@k8s-m1 tomcat-java-demo-master]# kubectl get ep
NAME ENDPOINTS AGE
kubernetes 10.0.0.23:6443 11d
nginx 10.244.215.76:80 11d
web 10.244.111.210:8080 22m
[root@k8s-m1 tomcat-java-demo-master]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-f89759699-qjjjb 1/1 Running 1 5d9h 10.244.215.76 k8s-n1 <none> <none>
web-6b9c78c94f-vvtks 1/1 Running 0 35m 10.244.111.210 k8s-n2 <none> <none>
YAML部署
YAML文件创建资源对象
YAML文件格式说明
YAML是一种简洁的非标记语言。
语法格式：
- 缩进表示层级关系
- 不支持制表符"tab”缩进，使用空格缩进
- 通常开头缩进2个空格
- 字符后缩进1个空格，如冒号、逗号等
- ‘---’ 表示YAML格式，一个文件的开始
- #”注释
编写 yml 配置文件
[root@k8s-m1 chp4]# cat deployment.yml apiVersion: apps/v1 kind: Deployment metadata: name: web2 spec: replicas: 1 selector: matchLabels: project: demo app: java template: metadata: labels: project: demo app: java spec: containers: - name: web image: lizhenliang/java-demo ports: - containerPort: 8080 [root@k8s-m1 chp4]# kubectl apply -f deployment.yml [root@k8s-m1 chp4]# cat service.yml kind: Service apiVersion: v1 metadata: name: web2 spec: selector: project: demo app: java ports: - protocol: TCP port: 80 targetPort: 8080 type: NodePort [root@k8s-m1 chp4]# kubectl apply -f service.yml [root@k8s-m1 chp4]# kubectl get svc,pod,deploy NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 12d service/nginx NodePort 10.96.231.76 <none> 80:31473/TCP 12d service/web NodePort 10.109.105.181 <none> 80:32116/TCP 24h service/web2 NodePort 10.100.117.24 <none> 80:31359/TCP 11m NAME READY STATUS RESTARTS AGE pod/nginx-f89759699-qjjjb 1/1 Running 2 6d9h pod/web-6b9c78c94f-vvtks 1/1 Running 1 24h pod/web2-564664575d-v9768 1/1 Running 0 14m NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/nginx 1/1 1 1 12d deployment.apps/web 1/1 1 1 24h deployment.apps/web2 1/1 1 1 14m
服务编排：资源字段太多，记不住怎么办
用 create命令生成 kubectl create deployment nginx --image=nginx：1.16 -o yaml --dry-run=client > my-deploy.yaml
-o 选项：json|yaml|name|wide --dry-run 尝试不实际创建 用get命令导出 kubectl get deployment web -o yaml >web.yaml Pod容器的字段拼写忘记了 kubectl explain pods.spec.containers kubectl explain deployment
Pod与 Deployment的关系
Deployment是最为常用的 controllers（也称为 workload），其他控制器还有 Daemon Set、 StatefulSet等。
controllers特点
- controllers：在集群上管理和运行容器的对象
- 通过labe- selector相关联
- Pod通过控制器实现应用的运维，如伸缩，滚动升级等
Deployment 控制器介绍
Deployment的功能：
- 管理Pod和 ReplicaSe
- 具有上线部署、副本设定、滚动升级、回滚等功能
- 提供声明式更新，例如只更新一个新的 Image
应用场景：网站、API、微服务
应用升级、弹性伸缩、回滚、删除
应用升级
kubectl set image deployment/web nginx=nginx:1.16
# 查看升级状态
kubectl rollout status deployment/web
[root@k8s-m1 chp4]# kubectl set image deployment web java-demo=tomcat:8 deployment.apps/web image updated [root@k8s-m1 chp4]# kubectl get pod NAME READY STATUS RESTARTS AGE nginx-f89759699-qjjjb 1/1 Running 2 6d9h web-69fd684457-t9qb9 0/1 ContainerCreating 0 23s web-6b9c78c94f-vvtks 1/1 Running 1 25h web2-564664575d-v9768 1/1 Running 0 23m [root@k8s-m1 chp4]# kubectl get pod NAME READY STATUS RESTARTS AGE nginx-f89759699-qjjjb 1/1 Running 2 6d9h web-69fd684457-t9qb9 0/1 ContainerCreating 0 30s web-6b9c78c94f-vvtks 1/1 Running 1 25h web2-564664575d-v9768 1/1 Running 0 23m [root@k8s-m1 chp4]# kubectl get pod NAME READY STATUS RESTARTS AGE nginx-f89759699-qjjjb 1/1 Running 2 6d9h web-69fd684457-t9qb9 0/1 ContainerCreating 0 41s web-6b9c78c94f-vvtks 1/1 Running 1 25h web2-564664575d-v9768 1/1 Running 0 23m [root@k8s-m1 chp4]# kubectl get pod NAME READY STATUS RESTARTS AGE nginx-f89759699-qjjjb 1/1 Running 2 6d9h web-69fd684457-t9qb9 1/1 Running 0 70s web-6b9c78c94f-vvtks 0/1 Terminating 1 25h web2-564664575d-v9768 1/1 Running 0 24m [root@k8s-m1 chp4]# kubectl get pod NAME READY STATUS RESTARTS AGE nginx-f89759699-qjjjb 1/1 Running 2 6d9h web-69fd684457-t9qb9 1/1 Running 0 81s web2-564664575d-v9768 1/1 Running 0 24m [root@k8s-m1 chp4]# kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 12d nginx NodePort 10.96.231.76 <none> 80:31473/TCP 12d web NodePort 10.109.105.181 <none> 80:32116/TCP 25h web2 NodePort 10.100.117.24 <none> 80:31359/TCP 22m
[root@k8s-m1 chp4]# kubectl rollout history deployment web deployment.apps/web REVISION CHANGE-CAUSE 1 <none> 2 <none> [root@k8s-m1 chp4]# kubectl rollout undo deployment web deployment.apps/web rolled back
[root@k8s-m1 chp4]# kubectl rollout history deployment web deployment.apps/web REVISION CHANGE-CAUSE 2 <none> 3 <none> [root@k8s-m1 chp4]# kubectl set image -h Update existing container image(s) of resources.
Possible resources include (case insensitive): [root@k8s-m1 chp4]# kubectl set image deployment web java-demo=tomcat:8 --record=true deployment.apps/web image updated [root@k8s-m1 chp4]# kubectl rollout history deployment web deployment.apps/web REVISION CHANGE-CAUSE 3 <none> 4 kubectl set image deployment web java-demo=tomcat:8 --record=true
弹性伸缩
#手动扩容 kubectl scale deployment web --replicas=10 #自动水平扩容 kubectl autoscale deployment web --min=3 --max=10 --cpu-percent=80 kubectl get hpa
回滚
kubectl rollout history deployment/web kubectl rollout undo deployment/web #回滚上一个版 kubectl rollout undo deployment/web --to-revision=2 #回滚指定版本
删除 kubectl delete deploy/web kubectl delete svc/web
资源限制
[root@k8s-m1 chp4]# cat deployment-cpu.yml apiVersion: apps/v1 kind: Deployment metadata: name: web2 spec: replicas: 1 selector: matchLabels: project: demo app: java template: metadata: labels: project: demo app: java spec: containers: - name: web image: lizhenliang/java-demo ports: - containerPort: 8080 resources: requests: cpu: 500m limits: cpu: 1
使用HPA前提：
1、部署metrics-server
2、部署pod要设置requests
