스프링 부트에서 도커 컨테이너 이미지 생성하기

스프링 부트에서 도커 컨테이너 이미지 생성하기

• 개발 환경
  • Intellij IDE
  • Maven

참고 사이트 : https://spring.io/guides/gs/spring-boot-docker/

예제 코드 생성

@SpringBootApplication
@RestController
public class DockerTestApplication {

    @RequestMapping("/")
    public String sayHello() {
        return "Hello CI";
    } 

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

}

• maven 을 활용하여 jar 파일 생성 및 실행

$ mvn package && java -jar target/*.jar
$ curl localhost:8080                                        
Hello CI

Dockerfile 생성

• maven package 로 생성된 jar 파일을 컨테이너 이미지 안에 넣고 엔트리 포인트를 지정한다.

FROM openjdk:8-jdk-alpine
ARG JAR_FILE=target/*.jar
COPY ${JAR_FILE} app.jar
ENTRYPOINT ["java","-jar","/app.jar"]

Docker 이미지 생성

• 실행 명령어 : docker build -t ci/hello-ci .

$docker build -t ci/hello-ci .                                                 SIGINT(2) ↵
Sending build context to Docker daemon  16.75MB
Step 1/4 : FROM openjdk:8-jdk-alpine
8-jdk-alpine: Pulling from library/openjdk
e7c96db7181b: Pull complete
f910a506b6cb: Pull complete
c2274a1a0e27: Pull complete
Digest: sha256:94792824df2df33402f201713f932b58cb9de94a0cd524164a0f2283343547b3
Status: Downloaded newer image for openjdk:8-jdk-alpine
 ---> a3562aa0b991
Step 2/4 : ARG JAR_FILE=target/*.jar
 ---> Running in a50bdf4f6a76
Removing intermediate container a50bdf4f6a76
 ---> a44d7bc3b35f
Step 3/4 : COPY ${JAR_FILE} app.jar
 ---> ca072fc923ee
Step 4/4 : ENTRYPOINT ["java","-jar","/app.jar"]
 ---> Running in d5fb7258f922
Removing intermediate container d5fb7258f922
 ---> 336f8ce8cdc3
Successfully built 336f8ce8cdc3
Successfully tagged ci/hello-ci:latest

Docker 이미지 실행

• 실행 명령어 : docker run -p 8080:8080 ci/hello-ci

$ docker run -p 8080:8080 ci/hello-ci                                                



  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.3.1.RELEASE)

2020-07-08 00:46:10.959  INFO 1 --- [           main] c.e.dockertest.DockerTestApplication     : Starting DockerTestApplication v0.0.1-SNAPSHOT on 145d1d9f806a with PID 1 (/app.jar started by root in /)
2020-07-08 00:46:10.968  INFO 1 --- [           main] c.e.dockertest.DockerTestApplication     : No active profile set, falling back to default profiles: default
2020-07-08 00:46:13.175  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2020-07-08 00:46:13.211  INFO 1 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2020-07-08 00:46:13.212  INFO 1 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.36]
2020-07-08 00:46:13.399  INFO 1 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2020-07-08 00:46:13.400  INFO 1 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 2305 ms
2020-07-08 00:46:14.013  INFO 1 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2020-07-08 00:46:14.453  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2020-07-08 00:46:14.480  INFO 1 --- [           main] c.e.dockertest.DockerTestApplication     : Started DockerTestApplication in 4.277 seconds (JVM running for 5.158)