在kubernetes集群中部署SpringBoot应用和MySQL

逃离我推掉我的手 2022-12-04 09:25 300阅读 0赞

# 环境准备 #

需要k8s集群和本地仓库，如果你还没有搭建，建议参考我上面两篇文章 [Kubernetes集群搭建详细指南][Kubernetes]、 [为kubernetes创建本地镜像仓库  
][kubernetes_]

# 部署MySQL #

首先我们需要创建持久卷和持久卷声明，用来为MySQL挂载存储，不然容器重启数据就丢失了。

### 1）创建持久卷和持久卷声明 ###

将以下的yaml声明保存为mysql-pv.yaml，然后执行apply命令。

apiVersion: v1
    kind: PersistentVolume
    metadata:
      name: mysql-pv-volume
      labels:
        type: local
    spec:
      storageClassName: manual
      capacity:
        storage: 1Gi
      accessModes:
        - ReadWriteOnce
      hostPath:
        path: "/mnt/data"
    ---
    apiVersion: v1
    kind: PersistentVolumeClaim
    metadata:
      name: mysql-pv-claim
    spec:
      storageClassName: manual
      accessModes:
        - ReadWriteOnce
      resources:
        requests:
          storage: 1Gi

kubectl apply -f mysql-pv.yaml

### 2）部署MySQL 5.6 ###

这里选择了MySQL5.6的版本，你也可以换成其他的。

将以下的yaml声明保存为mysql-deployment.yaml，然后执行apply命令。

我们创建MySQL的同时创建了Service，Service为集群中的容器通信提供了服务发现功能。

apiVersion: v1
    kind: Service
    metadata:
      name: mysql
      labels:
        app: mysql
    spec:
      ports:
        - port: 3306
      selector:
        app: mysql
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: mysql
    spec:
      selector:
        matchLabels:
          app: mysql
      strategy:
        type: Recreate
      template:
        metadata:
          labels:
            app: mysql
        spec:
          containers:
            - image: mysql:5.6
              name: mysql
              env:
                - name: MYSQL_ROOT_PASSWORD
                  value: mysql520
              ports:
                - containerPort: 3306
                  name: mysql
              volumeMounts:
                - name: mysql-persistent-storage
                  mountPath: /var/lib/mysql
          volumes:
            - name: mysql-persistent-storage
              persistentVolumeClaim:
                claimName: mysql-pv-claim

kubectl apply -f mysql-deployment.yaml

查看部署结果：

[root@k8s-master spring-boot-k8s-app]# kubectl get pods
    NAME                     READY   STATUS    RESTARTS   AGE
    mysql-7446cc569d-nglnb   1/1     Running   4          40m

# 部署SpringBoot应用 #

## 1）在项目根目录创建Dockerfile ##

你的项目中要将`spring-boot-k8s-app.jar`替换成自己的jar。

FROM  openjdk:8-jdk
    WORKDIR /opt/
    COPY target/spring-boot-k8s-app.jar /opt/
    EXPOSE 8080
    CMD ["java","-Djava.security.egd=file:/dev/./urandom","-Xms400m","-Xmx400m","-jar","/opt/spring-boot-k8s-app.jar", "--spring.profiles.active=prod"]

## 2）记得修改配置文件中datasource ##

如下，其中url的第二个`mysql`即为我们之前创建MySQL的service名称。MySQL的`username`和`password`则通过环境变量的形式读取，实际生产环境更推荐用`Secret`来加密存储MySQL的用户名和密码。

spring:
      datasource:
        url: jdbc:mysql://mysql:3306/demo?useSSL=false&useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai&zeroDateTimeBehavior=convertToNull&autoReconnect=true
        username: ${ MYSQL_USERNAME}
        password: ${ MYSQL_PASSWORD}
        initialization-mode: always

## 3）创建资源定义文件yaml ##

在项目根目录下创建deploy文件夹，按照如下创建`spring-boot-deployment.yaml`文件，并放到deploy文件夹下。根据你的实际集群环境，你需要替换`192.168.6.128:5000`为自己的镜像仓库。

kind: Service
    apiVersion: v1
    metadata:
      name: spring-boot-k8s-app-service
    spec:
      type: NodePort
      selector:
        app: spring-boot-k8s-app
      ports:
        - protocol: TCP
          port: 8080
          nodePort: 32082
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: spring-boot-k8s-app-deployment
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: spring-boot-k8s-app
      template:
        metadata:
          labels:
            app: spring-boot-k8s-app
        spec:
          containers:
            - name: spring-boot-k8s-app-controller
              image: 192.168.6.128:5000/spring-boot-k8s-app:20200907-011935
              ports:
                - containerPort: 8080
              env:
                - name: MYSQL_PORT
                  value: '3306'
                - name: MYSQL_USERNAME
                  value: root
                - name: MYSQL_PASSWORD
                  value: mysql520

## 4）一把梭命令脚本 ##

为了免去手工部署敲命令的烦恼，直接一把梭将命令整合成如下的bash脚本，命名为`auto-deploy.sh`，并扔进deploy文件夹下。这个脚本就实现了这么几件事：

*  从git拉取最新代码
 *  maven打包
 *  打docker镜像
 *  推送镜像到本地仓库
 *  更新Deployment资源模板文件的镜像tag
 *  按照更新后的文件进行部署

git pull origin master
    mvn clean package -DskipTests
    tag=$(date +"%Y%m%d-%H%M%S")
    if [ $# -eq 1 ]; then
        tag=$1
    fi
    image=localhost:5000/spring-boot-k8s-app:$tag
    imagename=spring-boot-k8s-app:$tag
    
    docker build -t $image .
    docker push $image
    echo "$image"
    
    echo "$imagename"
    pwd
    
    cp deploy/spring-boot-deployment.yaml deploy/spring-boot-deployment-tmp.yaml
    
    sed -i s#spring-boot-k8s-app:[0-9]*-[0-9]*#$imagename# deploy/spring-boot-deployment-tmp.yaml
    
    kubectl apply -f deploy/spring-boot-deployment-tmp.yaml

## 5）通过脚本完成部署 ##

sh deploy/auto-deploy.sh

查看部署效果，发现调度到node2节点：

[root@k8s-master spring-boot-k8s-app]# kubectl get pods -o wide
    NAME                                              READY   STATUS    RESTARTS   AGE     IP            NODE        NOMINATED NODE   READINESS GATES
    mysql-7446cc569d-nglnb                            1/1     Running   4          138m    10.244.1.38   k8s-node1   <none>           <none>
    spring-boot-k8s-app-deployment-587b6dc8c8-bx792   1/1     Running   0          5m48s   10.244.2.29   k8s-node2   <none>           <none>

查看node2的ip：

[root@k8s-master spring-boot-k8s-app]# kubectl get nodes -o wide
    NAME         STATUS   ROLES    AGE   VERSION   INTERNAL-IP     EXTERNAL-IP   OS-IMAGE                KERNEL-VERSION               CONTAINER-RUNTIME
    k8s-master   Ready    master   2d    v1.19.0   192.168.6.128   <none>        CentOS Linux 7 (Core)   3.10.0-957.12.2.el7.x86_64   docker://18.6.1
    k8s-node1    Ready    <none>   2d    v1.19.0   192.168.6.131   <none>        CentOS Linux 7 (Core)   3.10.0-957.12.2.el7.x86_64   docker://18.6.1
    k8s-node2    Ready    <none>   2d    v1.19.0   192.168.6.132   <none>        CentOS Linux 7 (Core)   3.10.0-957.12.2.el7.x86_64   docker://18.6.1

由于当前springboot项目对应的Service为NodePort类型，那么它可以从集群外部通过NodeIp和NodePort进行访问。直接通过宿主机浏览器访问`http://192.168.6.132:32082/` 地址即可看到效果。

项目源码已上传到GitHub [spring-boot-k8s-app][]，有兴趣可以了解下。

[Kubernetes]: https://blog.csdn.net/mryang125/article/details/108429951
[kubernetes_]: https://blog.csdn.net/mryang125/article/details/108455644
[spring-boot-k8s-app]: https://github.com/Alphathur/spring-boot-k8s-app