Steps to deploy Spring Boot project using Docker

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.10.RELEASE</version>
</parent>

<dependencies>
     <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
 <dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-test</artifactId>
  <scope>test</scope>
 </dependency>
</dependencies>

@RestController
public class DockerController {
 
    @RequestMapping("/hello")
    public String hello() {
        return "hello,nihao";
    }
}

@SpringBootApplication
public class DockerApplication {

 public static void main(String[] args) {
  SpringApplication.run(DockerApplication.class, args);
 }
}

[root@jiangwang springbootDemo]# ls
demo-0.0.1-SNAPSHOT.jar Dockerfile
[root@jiangwang springbootDemo]# java -jar demo-0.0.1-SNAPSHOT.jar 

  . ____ _ __ _ _
 /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/ ___)| |_)| | | | | || (_| | ) ) ) )
  ' |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|===============|___/=/_/_/_/
 :: Spring Boot :: (v2.2.10.RELEASE)

2021-03-18 14:49:18.241 INFO 12886 --- [ main] com.example.demo.DemoApplication : Starting DemoApplication v0.0.1-SNAPSHOT on jiangwang with PID 12886 (/home/springbootDemo/demo-0.0.1-SNAPSHOT.jar started by root in /home/springbootDemo)
2021-03-18 14:49:18.244 INFO 12886 --- [ main] com.example.demo.DemoApplication : No active profile set, falling back to default profiles: default
2021-03-18 14:49:19.924 INFO 12886 --- [ main] osbwembedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2021-03-18 14:49:19.938 INFO 12886 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2021-03-18 14:49:19.938 INFO 12886 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.38]
2021-03-18 14:49:20.013 INFO 12886 --- [ main] oaccC[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2021-03-18 14:49:20.014 INFO 12886 --- [ main] wscServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1657 ms
2021-03-18 14:49:20.321 INFO 12886 --- [ main] ossconcurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2021-03-18 14:49:20.520 INFO 12886 --- [ main] osbwembedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2021-03-18 14:49:20.523 INFO 12886 --- [ main] com.example.demo.DemoApplication : Started DemoApplication in 2.899 seconds (JVM running for 3.369)

FROM java:8
COPY *.jar /app.jar

CMD ["--server.port=8080"]

EXPOSE 8080

ENTRYPOINT ["java","-jar","/app.jar"]

## Build the image [root@jiangwang springbootDemo]# docker build -t springboot-demo .
Sending build context to Docker daemon 17.72MB
Step 1/5: FROM java:8
 ---> d23bdf5b1b1b
Step 2/5 : COPY *.jar /app.jar
 ---> f4d6aeabd3f0
Step 3/5 : CMD ["--server.port=8080"]
 ---> Running in a6311f7cf7b5
Removing intermediate container a6311f7cf7b5
 ---> d8117b10cefa
Step 4/5: EXPOSE 8080
 ---> Running in ae180be637bb
Removing intermediate container ae180be637bb
 ---> f16702c75ab6
Step 5/5 : ENTRYPOINT ["java","-jar","/app.jar"]
 ---> Running in fafa00625666
Removing intermediate container fafa00625666
 ---> d4c3e225699d
Successfully built d4c3e225699d
Successfully tagged springboot-demo:latest

# Run the image [root@jiangwang springbootDemo]# docker run -d -p 39005:8080 --name my-springboot springboot-demo
7ac35852cb91cb10612cd28fdbe7c50c7c59df4cccf19b2f1d30dcabbfe501f4
[root@jiangwang springbootDemo]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7ac35852cb91 springboot-demo "java -jar /app.jar …" 33 seconds ago Up 32 seconds 0.0.0.0:39005->8080/tcp my-springboot
[root@jiangwang springbootDemo]# curl localhost:39005/hello
hello,nihao[root@jiangwang springbootDemo]#