环境
- kubernetes 1.20.4
- Spring Boot 2.5.0-M3
目标
新建 Spring Boot 项目，提供一个 GET 请求来修改项目的存活探针。
示例
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.0-M3</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>jiangbo.spring.demo</groupId>
<artifactId>spring-k8s</artifactId>
<version>liveness</version>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<scope>runtime</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
</pluginRepository>
</pluginRepositories>
</project>
接口定义
package jiangbo.spring.docker;
import java.net.InetAddress;
import java.util.List;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.availability.AvailabilityChangeEvent;
import org.springframework.boot.availability.LivenessState;
import org.springframework.context.ApplicationContext;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import lombok.AllArgsConstructor;
@AllArgsConstructor
@SpringBootApplication
@RestController
public class SpringDemoApplication {
private JdbcTemplate jdbcTemplate;
private ApplicationContext context;
private static String hostname;
public static void main(String[] args) throws Exception {
hostname = InetAddress.getLocalHost().getHostName();
SpringApplication.run(SpringDemoApplication.class, args);
}
@GetMapping("/hostname")
public String hello() {
return hostname;
}
private static final String SQL = "SELECT * FROM public.user";
@GetMapping("/users")
public List<Person> users() {
return jdbcTemplate.query(SQL, Person.ROW_MAPPER);
}
@GetMapping(value = "/liveness")
public String liveness(String name) {
LivenessState state = LivenessState.valueOf(name);
AvailabilityChangeEvent.publish(context, state);
return state.toString();
}
}
配置文件
management:
endpoint:
shutdown:
enabled: true
endpoints:
web:
exposure:
include: "*"
spring:
datasource:
url: jdbc:postgresql://192.168.56.103/postgres
username: postgres
password: 123456
logging:
level:
web: debug
pattern:
console: "%d{yyyy-MM-dd HH:mm:ss} - %msg%n"
打包并生成镜像
PS D:workspacestsspring-demo> docker build -t jiangbo920827/spring-k8s:liveness .
[+] Building 2.2s (12/12) FINISHED
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 32B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [internal] load metadata for docker.io/library/openjdk:8-jre-alpine 0.0s
=> [internal] load build context 0.3s
=> => transferring context: 23.26MB 0.3s
=> CACHED [stage-1 1/5] FROM docker.io/library/openjdk:8-jre-alpine 0.0s
=> [builder 2/3] COPY target/*.jar application.jar 0.3s
=> [builder 3/3] RUN java -Djarmode=layertools -jar application.jar extract 1.2s
=> CACHED [stage-1 2/5] COPY --from=builder dependencies/ ./ 0.0s
=> CACHED [stage-1 3/5] COPY --from=builder snapshot-dependencies/ ./ 0.0s
=> CACHED [stage-1 4/5] COPY --from=builder spring-boot-loader/ ./ 0.0s
=> [stage-1 5/5] COPY --from=builder application/ ./ 0.0s
=> exporting to image 0.0s
=> => exporting layers 0.0s
=> => writing image sha256:27e1956a7558e66cc463d09c86bcda059fd6534d520a9ab68fb8567048f786f2 0.0s
=> => naming to docker.io/jiangbo920827/spring-k8s:liveness 0.0s
PS D:workspacestsspring-demo> docker push jiangbo920827/spring-k8s:liveness
The push refers to repository [docker.io/jiangbo920827/spring-k8s]
31e294c1279b: Pushed
e323b9ec2845: Layer already exists
5f70bf18a086: Layer already exists
6d24f25c4501: Layer already exists
edd61588d126: Layer already exists
9b9b7f3d56a0: Layer already exists
f1b5933fe4b5: Layer already exists
liveness: digest: sha256:14e2cc6a35655774f0134d27cc947fce7bea64e9ce2f18fbfe32f3690200e7c4 size: 1782
总结
新建一个可以修改存活探针的 Spring Boot 项目，并且生成镜像传送到 Docker 仓库。