基于Java Spring Boot的云原生TodoList Demo 项目,验证云原生核心特性
以下是一个基于 Java Spring Boot 的云原生 TodoList Demo 项目,涵盖 容器化、Kubernetes 编排、CI/CD、可观测性、弹性扩缩容 等核心云原生特性,代码简洁且附详细操作指南,适合入门学习。
项目概览
- 目标:实现一个支持增删改查(CRUD)的 TodoList 后端服务,通过云原生技术栈部署,展示完整的云原生实践流程。
- 技术栈:
- 后端:Java 17 + Spring Boot 3.2(轻量、模块化)
- 数据库:PostgreSQL(云原生持久化存储)
- 容器化:Docker
- 编排:Kubernetes(K8s)
- CI/CD:GitHub Actions
- 可观测性:Prometheus(监控) + Grafana(可视化) + Loki(日志)
- 配置管理:Spring Cloud Config(可选,或直接使用 K8s ConfigMap)
一、项目结构
todolist-cloudnative/
├── src/ # 核心业务代码
│ ├── main/
│ │ ├── java/com/example/todo/
│ │ │ ├── controller/ # REST 接口
│ │ │ ├── model/ # 数据库实体
│ │ │ ├── repository/ # 数据访问层
│ │ │ ├── service/ # 业务逻辑层
│ │ │ └── TodoApplication.java # 启动类
│ │ └── resources/
│ │ ├── application.yml # 主配置
│ │ └── logback-spring.xml # 日志配置(Loki 集成)
│ └── test/ # 单元测试
├── docker/ # Docker 相关配置
│ └── Dockerfile # 容器化构建脚本(多阶段构建)
├── k8s/ # K8s 部署配置
│ ├── todo-deployment.yaml # 应用 Deployment
│ ├── todo-service.yaml # 应用 Service
│ ├── postgres-statefulset.yaml # PostgreSQL StatefulSet
│ ├── postgres-service.yaml # PostgreSQL Service
│ ├── configmap.yaml # 非敏感配置(K8s 注入)
│ └── secret.yaml # 敏感配置(数据库密码,K8s Secret)
├── prometheus/ # Prometheus 监控配置
│ └── todolist.yml # 抓取规则
├── .github/ # GitHub Actions 工作流
│ └── workflows/
│ └── deploy.yml # CI/CD 自动化流程
└── README.md # 操作指南
二、核心功能实现(Spring Boot 后端)
1. 初始化项目(Spring Initializr)
- 访问 https://start.spring.io/,选择:
- Project: Maven
- Language: Java
- Spring Boot: 3.2.0
- Dependencies:
- Spring Web(REST 接口)
- Spring Data JPA(数据库操作)
- PostgreSQL Driver(数据库驱动)
- Micrometer Tracing(可观测性)
- Actuator(健康检查、指标暴露)
2. 数据库模型(src/main/java/com/example/todo/model/TodoItem.java
)
import jakarta.persistence.*;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;@Entity
@Table(name = "todo_items")
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class TodoItem {@Id@GeneratedValue(strategy = GenerationType.IDENTITY)private Long id;@Column(nullable = false)private String title;private String description;@Column(columnDefinition = "BOOLEAN DEFAULT FALSE")private boolean completed;
}
3. 数据访问层(src/main/java/com/example/todo/repository/TodoRepository.java
)
import com.example.todo.model.TodoItem;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;@Repository
public interface TodoRepository extends JpaRepository<TodoItem, Long> {
}
4. 业务逻辑层(src/main/java/com/example/todo/service/TodoService.java
)
import com.example.todo.model.TodoItem;
import com.example.todo.repository.TodoRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import java.util.List;@Service
@RequiredArgsConstructor
public class TodoService {private final TodoRepository todoRepository;public TodoItem createTodo(TodoItem todoItem) {return todoRepository.save(todoItem);}public List<TodoItem> getAllTodos() {return todoRepository.findAll();}public TodoItem getTodoById(Long id) {return todoRepository.findById(id).orElseThrow(() -> new RuntimeException("Todo not found with id: " + id));}public TodoItem updateTodo(Long id, TodoItem updatedTodo) {TodoItem existingTodo = getTodoById(id);existingTodo.setTitle(updatedTodo.getTitle());existingTodo.setDescription(updatedTodo.getDescription());existingTodo.setCompleted(updatedTodo.isCompleted());return todoRepository.save(existingTodo);}public void deleteTodo(Long id) {todoRepository.deleteById(id);}
}
5. REST 接口(src/main/java/com/example/todo/controller/TodoController.java
)
import com.example.todo.model.TodoItem;
import com.example.todo.service.TodoService;
import lombok.RequiredArgsConstructor;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.*;import java.util.List;@RestController
@RequestMapping("/api/todos")
@RequiredArgsConstructor
public class TodoController {private final TodoService todoService;@PostMapping@ResponseStatus(HttpStatus.CREATED)public TodoItem createTodo(@RequestBody TodoItem todoItem) {return todoService.createTodo(todoItem);}@GetMappingpublic List<TodoItem> getAllTodos() {return todoService.getAllTodos();}@GetMapping("/{id}")public TodoItem getTodoById(@PathVariable Long id) {return todoService.getTodoById(id);}@PutMapping("/{id}")public TodoItem updateTodo(@PathVariable Long id, @RequestBody TodoItem updatedTodo) {return todoService.updateTodo(id, updatedTodo);}@DeleteMapping("/{id}")@ResponseStatus(HttpStatus.NO_CONTENT)public void deleteTodo(@PathVariable Long id) {todoService.deleteTodo(id);}
}
6. 配置外部化(src/main/resources/application.yml
)
spring:datasource:url: jdbc:postgresql://${POSTGRES_HOST}:${POSTGRES_PORT}/${POSTGRES_DB}username: ${POSTGRES_USER}password: ${POSTGRES_PASSWORD}driver-class-name: org.postgresql.Driverjpa:hibernate:ddl-auto: update # 自动创建表(生产环境建议用 flyway)show-sql: truemanagement:endpoints:web:exposure:include: health, info, metrics, prometheus # 暴露监控端点endpoint:health:show-details: always
三、容器化(Docker)
docker/Dockerfile
(多阶段构建,减小镜像体积)
# 阶段 1:构建 Maven 项目
FROM maven:3.9.6-eclipse-temurin-17 AS build
WORKDIR /app
COPY pom.xml .
# 缓存依赖(仅当 pom.xml 变化时重新下载)
RUN mvn dependency:go-offline -B
COPY src ./src
RUN mvn clean package -DskipTests# 阶段 2:运行 Spring Boot 应用
FROM eclipse-temurin:17-jre-alpine
WORKDIR /app
# 从构建阶段复制 JAR 包
COPY --from=build /app/target/todo-cloudnative-*.jar ./todo.jar
# 暴露 Spring Boot 端口(8080)
EXPOSE 8080
# 启动命令(禁用 Tomcat 优雅关闭,适配 K8s 探针)
CMD ["java", "-jar", "todo.jar", "--server.port=8080"]
四、Kubernetes 编排(云原生核心)
1. 配置管理(k8s/configmap.yaml
和 k8s/secret.yaml
)
非敏感配置(ConfigMap,注入数据库名、主机等):
apiVersion: v1
kind: ConfigMap
metadata:name: todo-config
data:POSTGRES_DB: "tododb"POSTGRES_HOST: "postgres-service" # K8s Service 名称(服务发现)
敏感配置(Secret,注入数据库用户、密码,需 base64 编码):
# 生成 base64 编码(实际生产建议用外部密钥管理系统如 HashiCorp Vault)
echo -n "admin" | base64 # 用户名
echo -n "mypassword" | base64 # 密码
echo -n "5432" | base64 # 端口
apiVersion: v1
kind: Secret
metadata:name: todo-secret
type: Opaque
data:POSTGRES_USER: "YWRtaW4=" # "admin" 的 base64POSTGRES_PASSWORD: "bXlwYXNzd29yZA==" # "mypassword" 的 base64POSTGRES_PORT: "NTQzNg==" # "5432" 的 base64
2. PostgreSQL 部署(k8s/postgres-statefulset.yaml
)
apiVersion: apps/v1
kind: StatefulSet
metadata:name: postgres
spec:serviceName: postgres-servicereplicas: 1 # 生产环境建议 3 副本 + 主从复制(Patroni)selector:matchLabels:app: postgrestemplate:metadata:labels:app: postgresspec:containers:- name: postgresimage: postgres:15-alpineenv:- name: POSTGRES_USERvalueFrom:secretKeyRef:name: todo-secretkey: POSTGRES_USER- name: POSTGRES_PASSWORDvalueFrom:secretKeyRef:name: todo-secretkey: POSTGRES_PASSWORD- name: POSTGRES_DBvalueFrom:configMapKeyRef:name: todo-configkey: POSTGRES_DBports:- containerPort: 5432volumeMounts:- name: postgres-datamountPath: /var/lib/postgresql/datavolumeClaimTemplates: # 持久化存储(云原生存储卷,如 AWS EBS、阿里云盘)- metadata:name: postgres-dataspec:accessModes: [ "ReadWriteOnce" ]resources:requests:storage: 1Gi
3. Todo 服务部署(k8s/todo-deployment.yaml
)
apiVersion: apps/v1
kind: Deployment
metadata:name: todo-deployment
spec:replicas: 2 # 初始副本数(弹性扩缩容基础)selector:matchLabels:app: todotemplate:metadata:labels:app: todospec:containers:- name: todoimage: your-docker-username/todolist:v1 # 替换为实际镜像地址ports:- containerPort: 8080env:- name: POSTGRES_USERvalueFrom:secretKeyRef:name: todo-secretkey: POSTGRES_USER- name: POSTGRES_PASSWORDvalueFrom:secretKeyRef:name: todo-secretkey: POSTGRES_PASSWORD- name: POSTGRES_HOSTvalueFrom:configMapKeyRef:name: todo-configkey: POSTGRES_HOST- name: POSTGRES_PORTvalueFrom:secretKeyRef:name: todo-secretkey: POSTGRES_PORT- name: POSTGRES_DBvalueFrom:configMapKeyRef:name: todo-configkey: POSTGRES_DBlivenessProbe: # 存活探针(自动重启异常实例)httpGet:path: /actuator/healthport: 8080initialDelaySeconds: 30periodSeconds: 10readinessProbe: # 就绪探针(流量路由前检查)httpGet:path: /actuator/healthport: 8080initialDelaySeconds: 5periodSeconds: 5resources: # 资源限制(K8s 调度依据)requests:cpu: "100m"memory: "256Mi"limits:cpu: "500m"memory: "512Mi"
4. 服务暴露(k8s/todo-service.yaml
和 k8s/todo-ingress.yaml
)
ClusterIP Service(内部访问):
apiVersion: v1
kind: Service
metadata:name: todo-service
spec:type: ClusterIPselector:app: todoports:- protocol: TCPport: 80targetPort: 8080
Ingress(外部访问,需安装 NGINX Ingress Controller):
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:name: todo-ingressannotations:nginx.ingress.kubernetes.io/rewrite-target: /
spec:rules:- http:paths:- path: /todospathType: Prefixbackend:service:name: todo-serviceport:number: 80
五、CI/CD 自动化(GitHub Actions)
.github/workflows/deploy.yml
name: Deploy to Kuberneteson:push:branches: [ "main" ]jobs:build-and-push:runs-on: ubuntu-lateststeps:- name: Checkout codeuses: actions/checkout@v4- name: Set up JDK 17uses: actions/setup-java@v4with:java-version: '17'distribution: 'temurin'- name: Build with Mavenrun: mvn clean package -DskipTests- name: Set up Docker Buildxuses: docker/setup-buildx-action@v3- name: Login to Docker Hubuses: docker/login-action@v3with:username: ${{ secrets.DOCKERHUB_USERNAME }}password: ${{ secrets.DOCKERHUB_TOKEN }}- name: Build and push Docker imageuses: docker/build-push-action@v5with:context: .file: docker/Dockerfilepush: truetags: your-docker-username/todolist:latest,your-docker-username/todolist:${{ github.sha }}deploy-to-k8s:needs: build-and-pushruns-on: ubuntu-lateststeps:- name: Checkout codeuses: actions/checkout@v4- name: Set up kubectluses: azure/setup-kubectl@v3with:version: 'v1.28.0'- name: Deploy to Kubernetes clusterrun: |# 替换镜像标签为最新提交 SHAsed -i "s|your-docker-username/todolist:v1|your-docker-username/todolist:${{ github.sha }}|g" k8s/todo-deployment.yaml# 应用 K8s 配置kubectl apply -f k8s/env:KUBECONFIG: ${{ secrets.KUBECONFIG }} # 从 GitHub Secrets 读取集群配置
六、可观测性配置
1. Prometheus 监控(prometheus/todolist.yml
)
scrape_configs:- job_name: "todo_service"scrape_interval: 15smetrics_path: "/actuator/prometheus"static_configs:- targets: ["todo-service:80"] # K8s Service 域名(集群内部可解析)
2. 日志集成(Loki)
- 在
logback-spring.xml
中配置 Logstash 或直接输出 JSON 格式日志:<configuration><appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender"><encoder class="net.logstash.logback.encoder.LogstashEncoder"/></appender><root level="info"><appender-ref ref="CONSOLE"/></root> </configuration>
- 使用 Promtail 收集日志并发送到 Loki(需额外部署 Promtail)。
3. Grafana 仪表盘(示例查询)
- 请求速率:
rate(http_server_requests_seconds_count{job="todo_service"}[5m])
- 平均延迟:
rate(http_server_requests_seconds_sum{job="todo_service"}[5m]) / rate(http_server_requests_seconds_count{job="todo_service"}[5m])
- JVM 内存使用:
jvm_memory_used_bytes{area="heap"}
七、云原生特性验证
1. 容器化
- 本地构建镜像:
docker build -t todolist:v1 -f docker/Dockerfile .
- 运行测试:
docker run -p 8080:8080 todolist:v1
,访问http://localhost:8080/api/todos
验证接口。
2. Kubernetes 部署
- 本地搭建 K8s 集群(Minikube 或 Kind):
minikube start
- 应用配置:
kubectl apply -f k8s/
- 查看状态:
kubectl get pods,svc,ingress
。
3. 弹性扩缩容
- 手动扩缩容:
kubectl scale deployment/todo-deployment --replicas=3
- 自动扩缩容(HPA):
apiVersion: autoscaling/v2 kind: HorizontalPodAutoscaler metadata:name: todo-hpa spec:scaleTargetRef:apiVersion: apps/v1kind: Deploymentname: todo-deploymentminReplicas: 2maxReplicas: 10metrics:- type: Resourceresource:name: cputarget:type: UtilizationaverageUtilization: 70 # CPU 使用率超 70% 自动扩容
4. 故障自愈
- 手动删除 Pod:
kubectl delete pod <pod-name>
,观察 K8s 自动重建新 Pod(状态变为Running
)。
5. 持续交付
- 推送代码到 GitHub
main
分支,触发 GitHub Actions 自动构建、测试、部署。
八、总结
通过这个 TodoList Demo,你可以完整体验云原生应用的核心流程:
- 容器化:用 Docker 封装应用,确保环境一致性。
- Kubernetes 编排:通过 Deployment、Service 等资源实现自动化管理。
- CI/CD:GitHub Actions 实现代码提交到生产的全自动化。
- 可观测性:Prometheus + Grafana 监控性能,Loki 收集日志。
- 弹性扩缩容:HPA 根据负载自动调整资源,保障高可用。
后续可扩展方向:
- 微服务拆分(如用户服务、待办服务),用 Istio 实现服务网格。
- 引入数据库读写分离(主从复制)。
- 添加认证鉴权(OAuth2、JWT)。
- 使用 Helm 打包 K8s 配置,简化多环境部署。