目的
Springbootアプリケーションをコンテナ化したことがなく、SpringbootのDockerコンテナ化の記事は見るが、Warパッケージのコンテナ化の記事は見た記憶がないのでWarでも問題なくコンテナ化できるか確認と練習のため。自分用メモ
プロジェクトの用意
コンテナ化の確認のためだけなので依存関係は最小限（画像はGradleになっているがMaven選択）
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>3.2.1</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.ryo</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>demo</name>
<description>demo</description>
<properties>
<java.version>17</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
コード
Hello文字列を返却するだけのRestControllerを定義
Controller.java
package com.example.demo;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class Controller {
@GetMapping("/hello")
public String ts(){
return "Hello";
}
}
Dockerfileの作成
公式のJDKのイメージにはJREがないとのことだったので、とりあえずは参考文献の勧め通りのイメージを使用、Dockerfileはプロジェクトの直下に配置
FROM eclipse-temurin:17-jdk-jammy as builder
WORKDIR /opt/app
COPY .mvn/ .mvn
COPY mvnw pom.xml ./
RUN ./mvnw dependency:go-offline
COPY ./src ./src
RUN ./mvnw clean install
FROM eclipse-temurin:17-jre-jammy
WORKDIR /opt/app
EXPOSE 8080
COPY --from=builder /opt/app/target/*.war /opt/app/*.war
ENTRYPOINT ["java", "-jar", "/opt/app/*.war"]
Docker compose
DockerComposeの設定ファイルを記載、こちらもプロジェクト直下に配置。上記で作成したDockerfileを直接ビルドするように設定
docker-compose.yaml
version: '3'
services:
# Javaの設定情報
java:
# コンテナ名
container_name: spring
build:
context: .
dockerfile: Dockerfile
ports:
- "8080:8080"
コンテナの起動、確認
コンテナを起動、localhostにアクセスしたところ文字列の表示が確認できた。とりあえずはWarでもJarの例とそんなに変わらずに起動できそう。
PS C:\expenses-app\demo> docker compose up
[+] Building 1.5s (17/17) FINISHED docker:default
=> [java internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 394B 0.0s
=> [java internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [java internal] load metadata for docker.io/library/eclipse-temurin:17-jre-jammy 1.3s
=> [java internal] load metadata for docker.io/library/eclipse-temurin:17-jdk-jammy 1.4s
=> [java auth] library/eclipse-temurin:pull token for registry-1.docker.io 0.0s
=> [java builder 1/7] FROM docker.io/library/eclipse-temurin:17-jdk-jammy@sha256:d87a5e63a3d0cc562a8c9207328311d72f9aaf8948b5ee082acf4c 0.0s
=> [java stage-1 1/3] FROM docker.io/library/eclipse-temurin:17-jre-jammy@sha256:aa1f60eb5c86df76fa2189f36eb062592748a733a9eaf577dcb20f 0.0s
=> [java internal] load build context 0.0s
=> => transferring context: 1.10kB 0.0s
=> CACHED [java stage-1 2/3] WORKDIR /opt/app 0.0s
=> CACHED [java builder 2/7] WORKDIR /opt/app 0.0s
=> CACHED [java builder 3/7] COPY .mvn/ .mvn 0.0s
=> CACHED [java builder 4/7] COPY mvnw pom.xml ./ 0.0s
=> CACHED [java builder 5/7] RUN ./mvnw dependency:go-offline 0.0s
=> CACHED [java builder 6/7] COPY ./src ./src 0.0s
=> CACHED [java builder 7/7] RUN ./mvnw clean install 0.0s
=> CACHED [java stage-1 3/3] COPY --from=builder /opt/app/target/*.war /opt/app/*.war 0.0s
=> [java] exporting to image 0.0s
=> => exporting layers 0.0s
=> => writing image sha256:0733b6b9cdf4f7b5e01b9f7104a225a09aff43e49993b4c3ac50616ebc2ca964 0.0s
=> => naming to docker.io/library/demo-java 0.0s
[+] Running 1/1
✔ Container spring Created 0.1s
Attaching to spring
spring |
spring | . ____ _ __ _ _
spring | /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
spring | ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
spring | \\/ ___)| |_)| | | | | || (_| | ) ) ) )
spring | ' |____| .__|_| |_|_| |_\__, | / / / /
spring | =========|_|==============|___/=/_/_/_/
spring | :: Spring Boot :: (v3.2.1)
spring |
spring | 2024-01-16T16:20:56.724Z INFO 1 --- [ main] com.example.demo.DemoApplication : Starting DemoApplication using Java 17.0.9 with PID 1 (/opt/app/*.war started by root in /opt/app)
spring | 2024-01-16T16:20:56.733Z INFO 1 --- [ main] com.example.demo.DemoApplication : No active profile set, falling back to 1 default profile: "default"
spring | 2024-01-16T16:20:57.412Z INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port 8080 (http)
spring | 2024-01-16T16:20:57.419Z INFO 1 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
spring | 2024-01-16T16:20:57.420Z INFO 1 --- [ main] o.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/10.1.17]
spring | 2024-01-16T16:20:57.458Z INFO 1 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
spring | 2024-01-16T16:20:57.459Z INFO 1 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 668 ms
spring | 2024-01-16T16:20:57.676Z INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port 8080 (http) with context path ''
spring | 2024-01-16T16:20:57.685Z INFO 1 --- [ main] com.example.demo.DemoApplication : Started DemoApplication in 1.254 seconds (process running for 1.549)
spring | 2024-01-16T16:21:05.082Z INFO 1 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
spring | 2024-01-16T16:21:05.082Z INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
spring | 2024-01-16T16:21:05.083Z INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 0 ms
