从源码到镜像：使用 Docker 多阶段构建 Spring Boot 镜像

多阶段构建

阶段一

使用Maven打包，拷贝工程源码、pom.xml文件。

阶段二

从阶段一拷贝构建好的jar包，配置运行参数等，完成 Spring Boot 应用构建镜像。

Dockerfile

FROM maven:3.8.5-eclipse-temurin-11-alpine AS build
WORKDIR /app
COPY src ./src
COPY pom.xml .
COPY settings.xml .
RUN mvn -s ./settings.xml -f ./pom.xml clean package -Dmaven.test.skip=true

FROM openjdk:11-oraclelinux8
COPY --from=build /app/target/*.jar /app/app.jar
ENTRYPOINT ["java", "-jar", "/app/app.jar"]

构建

docker build -t myapp2 .

输出

[+] Building 124.4s (14/14) FINISHED
 => [internal] load build definition from Dockerfile                                                                                                                                                              0.1s 
 => => transferring dockerfile: 32B                                                                                                                                                                               0.0s 
 => [internal] load .dockerignore                                                                                                                                                                                 0.1s 
 => => transferring context: 2B                                                                                                                                                                                   0.0s 
 => [internal] load metadata for docker.io/library/openjdk:11-oraclelinux8                                                                                                                                        0.0s 
 => [internal] load metadata for docker.io/library/maven:3.8.5-eclipse-temurin-11-alpine                                                                                                                          0.0s 
 => [build 1/6] FROM docker.io/library/maven:3.8.5-eclipse-temurin-11-alpine                                                                                                                                      0.0s 
 => [internal] load build context                                                                                                                                                                                 0.1s 
 => => transferring context: 2.58kB                                                                                                                                                                               0.0s 
 => CACHED [stage-1 1/2] FROM docker.io/library/openjdk:11-oraclelinux8                                                                                                                                           0.0s 
 => CACHED [build 2/6] WORKDIR /app                                                                                                                                                                               0.0s 
 => CACHED [build 3/6] COPY src ./src                                                                                                                                                                             0.0s 
 => CACHED [build 4/6] COPY pom.xml .                                                                                                                                                                             0.0s 
 => CACHED [build 5/6] COPY settings.xml .                                                                                                                                                                        0.0s 
 => [build 6/6] RUN mvn -s ./settings.xml -f ./pom.xml clean package -Dmaven.test.skip=true                                                                                                                     118.8s 
 => [stage-1 2/2] COPY --from=build /app/target/*.jar /app/app.jar                                                                                                                                                2.1s 
 => exporting to image                                                                                                                                                                                            2.0s 
 => => exporting layers                                                                                                                                                                                           1.9s 
 => => writing image sha256:42d3fb1b410fd0152a5f5fa376b0fbe33135049e1aaa56ac61cdc09c4cef2950                                                                                                                      0.0s 
 => => naming to docker.io/library/myapp2

运行

docker run -p 8080:8080 -d myapp2