简介

在文章《GraalVM和Spring Native尝鲜，一步步让Springboot启动飞起来，66ms完成启动》中，我们介绍了如何使用Spring Native和buildtools插件，打包出本地镜像，也打包成Docker镜像。本文探索一下，如果不通过这个插件来生成镜像。这样我们可以控制更多、了解更多。

创建Spring Boot项目

创建Spring Boot项目，引入Spring Native，我们主要使用的是Spring Native提供的AOT功能。如下：

      org.springframework.experimental    spring-native    ${spring-native.version}        org.springframework.boot    spring-boot-starter-web              org.springframework.experimental      spring-aot-maven-plugin      ${spring-native.version}                        test-generate                      test-generate                                    generate                      generate

Build image的时候，我们需要引用依赖库，所以加上下面的插件：

  maven-dependency-plugin            package              copy-dependencies                    ${project.build.directory}/lib

接着先编译出Java class，命令如下：

$ mvn clean package

打包本地镜像

前面的命令打包完，在target目录下会有一个lib目录，我们需要用上。通过native-image命令来生成镜像，如下：

$ native-image -cp ./target/classes/:target/lib/* com.pkslow.springboot.SpringbootGraalVMNativeMain Pkslow.SpringbootGraalVMNativeMain

这样就会生成一个可执行文件：Pkslow.SpringbootGraalVMNativeMain

执行如下：

$ ./Pkslow.SpringbootGraalVMNativeMain

使用了93ms来启动，还是很快的。

访问服务是正常的：

$ curl -i http://localhost:8080/hi-graalvmHTTP/1.1 200 Content-Type: text/plain;charset=UTF-8Content-Length: 67Date: Wed, 02 Nov 2022 15:08:44 GMTThis message is from Spring Boot built/run by GraalVM/Spring Native

创建Docker镜像

先拉取基础镜像：

$ docker pull springci/graalvm-ce:java11-0.12.x

进入容器看一下里面的状况：

$ docker run -it --rm --entrypoint bash springci/graalvm-ce:java11-0.12.xroot@d9b54bdce70a:/# pwd/root@d9b54bdce70a:/# java --versionopenjdk 11.0.15 2022-04-19OpenJDK Runtime Environment GraalVM 22.1.1.0-dev (build 11.0.15+10-jvmci-22.1-b06)OpenJDK 64-Bit Server VM GraalVM 22.1.1.0-dev (build 11.0.15+10-jvmci-22.1-b06, mixed mode, sharing)root@d9b54bdce70a:/# which java/opt/java/bin/javaroot@d9b54bdce70a:/# which native-image/opt/java/bin/native-image

准备一下Dockerfile如下：

FROM springci/graalvm-ce:java11-0.12.xVOLUME /tmpARG PORT=8080ARG TIME_ZONE=Asia/ShanghaiENV TZ=${TIME_ZONE}EXPOSE ${PORT}RUN pwdRUN mkdir /pkslow-applicationWORKDIR /pkslow-application/RUN cd /pkslow-applicationCOPY target/classes/ /pkslow-application/classes/COPY target/lib/ /pkslow-application/lib/RUN native-image -cp /pkslow-application/classes/:/pkslow-application/lib/* \    com.pkslow.springboot.SpringbootGraalVMNativeMain \    Pkslow.SpringbootGraalVMNativeMainENTRYPOINT ["/pkslow-application/Pkslow.SpringbootGraalVMNativeMain"]

打包Docker镜像：

$ docker build . -t pkslow/spring-boot-native-without-buildtools:1.0-SNAPSHOT -f src/main/dker/Dockerfile

完成后通过下面命令启动，57ms完成启动：

$ docker run -it -p 8080:8080 --rm pkslow/spring-boot-native-without-buildtools:0-SNAPSHOT2022-11-02 23:48:40.918  INFO 1 --- [           main] o.s.nativex.NativeListener               : AOT mode enabled  .   ____          _            __ _ _ /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/  ___)| |_)| | | | | || (_| |  ) ) ) )  '  |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot ::                (v2.6.2)2022-11-02 23:48:40.920  INFO 1 --- [           main] c.p.s.SpringbootGraalVMNativeMain        : Starting SpringbootGraalVMNativeMain using Java 11.0.15 on 12528bd45fd7 with PID 1 (/pkslow-application/Pkslow.SpringbootGraalVMNativeMain started by root in /pkslow-application)2022-11-02 23:48:40.920  INFO 1 --- [           main] c.p.s.SpringbootGraalVMNativeMain        : No active profile set, falling back to default profiles: default2022-11-02 23:48:40.934  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)2022-11-02 23:48:40.935  INFO 1 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]2022-11-02 23:48:40.935  INFO 1 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.56]2022-11-02 23:48:40.940  INFO 1 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext2022-11-02 23:48:40.940  INFO 1 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 19 ms2022-11-02 23:48:40.963  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''2022-11-02 23:48:40.964  INFO 1 --- [           main] c.p.s.SpringbootGraalVMNativeMain        : Started SpringbootGraalVMNativeMain in 0.057 seconds (JVM running for 0.061)2022-11-02 23:48:57.098  INFO 1 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'2022-11-02 23:48:57.098  INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'2022-11-02 23:48:57.098  INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 0 ms

测试正常启动：

$ curl -i http://127.0.0.1:8080/hi-graalvmHTTP/1.1 200 Content-Type: text/plain;charset=UTF-8Content-Length: 67Date: Wed, 02 Nov 2022 15:49:05 GMTThis message is from Spring Boot built/run by GraalVM/Spring Native

为了集成打包镜像到CI/CD中，在pom添加以下插件：

  org.codehaus.mojo  exec-maven-plugin  3.0.0            install              exec                    ${docker.skip}        docker                  build          .          -t          pkslow/${project.artifactId}:${project.version}          -f          src/main/docker/Dockerfile

通过以下命令即可生成Docker镜像：

$ mvn clean install -Ddocker.skip=false

代码

代码请看GitHub: https://github.com/LarryDpk/pkslow-samples