在 Kubernetes 中部署 SpringBoot 应用

在 Kubernetes 中部署 SpringBoot 应用

在 Kubernetes 中通过yaml 配置文件预先声明部署 SpringBoot 应用

代码地址 https://github.com/helloworlde/k8s-service

创建 SpringBoot 应用

• 创建名为 k8s-service 的 SpringBoot 应用
• 添加 REST API
  • K8sController.java

package cn.com.hellowood.k8sservice.controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/")
public class K8sController {

    @GetMapping("/")
    public String root() {
        return "Hello Kubernetes";
    }

    @GetMapping("/healthz")
    public String healthz() {
        return "ok";
    }
}

• 添加 Dockerfile

FROM openjdk:8-jdk-alpine
VOLUME /tmp
ENV TZ=Asia/Shanghai
RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
ARG JAR_FILE
ADD ${JAR_FILE} app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom", "-Duser.timezone=GMT+08", "-jar","/app.jar"]

• 编译打包

./gradlew clean build -x test

• 生成并推送镜像

./gradlew dockerPush -i

在 Kubernetes 中添加服务

• 添加 k8s-demo.yaml

apiVersion: v1
kind: Service
metadata:
  name: k8s-service
  namespace: default
  labels:
    app: k8s-service
spec:
  type: NodePort
  ports:
  - port: 8080
    nodePort: 30002
  selector:
    app: k8s-service

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: k8s-service
  labels:
    app: k8s-service
spec:
  replicas: 1
  selector:
    matchLabels:
      app: k8s-service
  template:
    metadata:
      labels:
        app: k8s-service
    spec:
      containers:
      - name: k8s-service
        image: registry.cn-qingdao.aliyuncs.com/hellowoodes/k8s-service
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 8080
        livenessProbe:
          httpGet:
            port: 8080
            path: /healthz
            scheme: HTTP
          periodSeconds: 15
          initialDelaySeconds: 30

• 创建服务

kubectl apply -f k8s-service.yaml 

• 等待服务启动之后访问 ${NodeIP}:30002，会返回 Hello Kubernetes，部署完成