springboot-docker.md

OCI 容器(Spring Boot 2.3后支持)

1. maven 插件支持

   <plugin>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-maven-plugin</artifactId>
       <configuration>
           <image>
               <name>afs.com/${project.artifactId}:v1</name>
           </image>
       </configuration>
   </plugin>

2. 运行命令

   mvn clean -Dmaven.test.skip spring-boot:build-image

3. 问题

   1. 网络问题 --> 升级 Spring Boot 到 2.4.1
   

dive 工具查看镜像内分层

1. 安装

   # RHEL/CentOS
   wget https://github.com/wagoodman/dive/releases/download/v0.9.2/dive_0.9.2_linux_amd64.deb
   sudo apt install ./dive_0.9.2_linux_amd64.deb
   # Ubantu/Debian
   wget https://github.com/wagoodman/dive/releases/download/v0.9.2/dive_0.9.2_linux_amd64.deb
   sudo apt install ./dive_0.9.2_linux_amd64.deb
   

2. 使用

   dive [image-tag]
   

3. github 地址

分阶层构建和 Dockerfile 的改进

1. maven 插件添加分层属性

   <plugin>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-maven-plugin</artifactId>
       <configuration>
           <image>
               <name>afs.com/${project.artifactId}:v1</name>
           </image>
           <layers>
               <enabled>true</enabled>
           </layers>
       </configuration>
   </plugin>

2. 查看 jar 包的内部分层信息

[root@host]# java -Djarmode=layertools -jar [target-jar] list
dependencies
spring-boot-loader
snapshot-dependencies
application

3. 编写分层的 Dockerfile

# the first stage of our build will extract the layers
FROM openjdk:8-jdk-alpine as builder
WORKDIR application
ARG JAR_FILE=target/*.jar
COPY ${JAR_FILE} app.jar
RUN java -Djarmode=layertools -jar app.jar extract

# the second stage of our build will copy the extracted layers
FROM openjdk:8-jdk-alpine
WORKDIR application
COPY --from=builder application/dependencies ./
COPY --from=builder application/spring-boot-loader ./
COPY --from=builder application/snapshot-dependencies ./
COPY --from=builder application/application/ ./
ENTRYPOINT ["java", "org.springframework.boot.loader.JarLauncher"]

4. dive 查看镜像层级信息

Creating Optimized Docker Images for a Spring Boot Application