SpringBoot打包成Docker镜像的项目实践

FROM java:8
#此处的*为正则表达式，表示以.jar结尾的同步录下的文件（这里的jar是maven打包好的）
COPY *.jar /app.jar

CMD ["--server.port=8080"]
EXPOSE 8080
ENTRYPOINT ["java","-jar","/app.jar"]

FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG DEPENDENCY=target/dependency # jar包解压位置
COPY ${DEPENDENCY}/BOOT-INF/lib /app/lib
COPY ${DEPENDENCY}/META-INF /app/META-INF
COPY ${DEPENDENCY}/BOOT-INF/classes /app
ENTRYPOINT ["java","-cp","app:app/lib/*","com.example.MyApplication"]

# 指定基础镜像，这是分阶段构建的前期阶段
FROM openjdk:8 as builder
# 执行工作目录
WORKDIR application
# 配置参数
ARG JAR_FILE=target/*.jar
# 将编译构建得到的jar文件复制到镜像空间中
COPY ${JAR_FILE} application.jar
# 通过工具spring-boot-jarmode-layertools 从application.jar 中提取拆分后的构建结果
RUN java -Djarmode=layertools -jar application.jar extract

# 正式构建镜像
FROM openjdk:8
WORKDIR application
# 前一阶段从jar中提取除了多个文件，这里分别执行COPY命令将他们复制到镜像空间中，每次COPY都是一个layer
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","-Duser.timezone=GMT+8","org.springframework.boot.loader.JarLauncher"]

# '-t' 设置打包镜像tag， '-f' 设置DockerFile文件， '.'选择当前目录
docker build -t test:1.0 -f .\DockerFile .