dockerfile-maven-plugin极简教程(推荐)

一、简介

maven是一个项目依赖管理和构建的工具，dockerfile-maven-plugin是一个maven的插件，主要作用是在项目构建的时候生成基于项目的docker镜像文件。

简而言之，此插件将maven和docker进行集成。

正常情况下，我们在开发了一个应用程序后，会使用maven进行打包，生成对应的jar文件。而后，会使用docker将jar文件build成一个镜像（docker image）。之后，就可以在docker daemon中创建基于镜像的容器，并可提供服务了。

dockerfile-maven-plugin的目标就是将maven的打包过程和docker的build过程结合在一起，当成功打包，既生成了对应的jar，也已生成了对应的docker镜像。当然，这只是最基础的功能，更详细的功能参见：https://github.com/spotify/dockerfile-maven

二、概述

我们知道maven是apache公司开发的一个产品，但是dockerfile-maven-plugin并不是apache官方开发的插件，是由一个叫做Spotify的组织开发的。

github主页：https://spotify.github.io/

github开源地址：https://github.com/spotify/dockerfile-maven

本文仅讨论如何基于一个Spring Boot的项目生成对应的docker镜像。

基本的原理如下：

• 首先，dockerfile-maven-plugin插件已经存储在maven的仓库中
• 然后，当在本地开发的时候，需要在项目的pom文件中引入此插件，在pom-build-plugins下面增加plugin配置节点
• 再然后，在executions节点中配置此插件如何工作；并且在configuration节点中加入需要的配置信息
• 最后，当我们执行mvn package的时候就可以得到docker image 了

环境：

• Ideal版本：2020.01
• java版本：8
• maven版本：3.6.1
• docker版本：19.03.12

ideal和docker deamon运行在同一台机器上面

三、将spring-boot-app打包成docker镜像

创建示例应用

使用ideal自带的Spring Initializr生成一个Spring Web 的示例项目

app对外提供一个hello的接口，访问该接口可以得到Hello，World的响应结果。应用主启动类代码如下：

package com.naylor.dockerfilemavenplugin;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/")
@SpringBootApplication
public class DockerfileMavenPluginApplication {

  public static void main(String[] args) {
    SpringApplication.run(DockerfileMavenPluginApplication.class, args);
  }

  @GetMapping("/hello")
  public String hello(){
    return "Hello,World";
  }

}

编译并运行项目，在浏览器中访问「http://127.0.0.1:8080/hello」 可以得到预期的响应结果

修改pom文件

在pom中增加对dockerfile-maven-plugin插件的引用，核心代码如下:

 <!--  dockerfile-maven-plugin   -->
      <plugin>
        <groupId>com.spotify</groupId>
        <artifactId>dockerfile-maven-plugin</artifactId>
        <version>1.3.6</version>
        <executions>
          <execution>
            <id>default</id>
            <goals>
              <goal>build</goal>

            </goals>
          </execution>
        </executions>
        <configuration>
          <repository>com.naylor/${project.artifactId}</repository>
          <tag>${project.version}</tag>
          <buildArgs>
            <JAR_FILE>${project.build.finalName}.jar</JAR_FILE>
          </buildArgs>
        </configuration>
      </plugin>

其中：

• g,a,v 为对插件的引用
• executions中的build标识，在maven的packege环节执行此插件
• configuration中的repository是生成的镜像的repository信息
• tag为镜像的tag信息
• buildArgs是在docker构建镜像过程中的参数，此处定义的JAR_FILE参数在执行docker build 的时候会消费

完整的pom文件如下：

<?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>2.3.4.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>
  <groupId>com.naylor</groupId>
  <artifactId>dockerfile-maven-plugin</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>dockerfile-maven-plugin</name>
  <description>Demo project for Spring Boot</description>

  <properties>
    <java.version>1.8</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-test</artifactId>
      <scope>test</scope>
      <exclusions>
        <exclusion>
          <groupId>org.junit.vintage</groupId>
          <artifactId>junit-vintage-engine</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>

      <!--  dockerfile-maven-plugin   -->
      <plugin>
        <groupId>com.spotify</groupId>
        <artifactId>dockerfile-maven-plugin</artifactId>
        <version>1.3.6</version>
        <executions>
          <execution>
            <id>default</id>
            <goals>
              <goal>build</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <repository>com.naylor/${project.artifactId}</repository>
          <tag>${project.version}</tag>
          <buildArgs>
            <JAR_FILE>${project.build.finalName}.jar</JAR_FILE>
          </buildArgs>
        </configuration>
      </plugin>
    </plugins>
  </build>

</project>

增加Dockerfile文件

在项目根目录（和pom文件在同一级）新建一个Dokerfile文件，文件内容如下:

FROM java:8
EXPOSE 8080
ARG JAR_FILE
ADD target/${JAR_FILE} /app.jar
ENTRYPOINT ["java", "-jar","/app.jar"]

使用Maven打包应用

首先清理一下maven工程，在ideal的Maven面版中点击Lifecycle-clean或者使用命令行执行mvn clean。

然后，使用maven构建app，在ideal的Maven面版中点击Liftcycle-package或者使用命令行执行 mvn package

再然后在命令行工具中执行docker image ls ，如果不出意外，可以看到一个repository为com.naylor/dockerfile-maven-plugin的docker镜像。

运行应用镜像

在命令行工具中执行如下命令运行容器：

docker run -d -p 8081:8080 ImageId

• ImageId为上一步生成的镜像的id，每次生成的镜像id都不一样
• 此命令作用为基于ImageId构建一个容器，将宿主机的8081端口映射到容器的8080端口

在宿主机浏览器中访问「http://127.0.0.1:8081/hello」可以得到Hello,World的响应。

四、分析mvn package 命令的控制台输出

通过mvn package的控制台输出，我们可以清晰的观察到整个流程的执行步骤，完整的输出如下:

/Library/Java/JavaVirtualMachines/jdk1.8.0_231.jdk/Contents/Home/bin/java -Dmaven.multiModuleProjectDirectory=/Users/chenhd/code/DebrisApp_Springboot/debris-app "-Dmaven.home=/Applications/IntelliJ IDEA 2.app/Contents/plugins/maven/lib/maven3" "-Dclassworlds.conf=/Applications/IntelliJ IDEA 2.app/Contents/plugins/maven/lib/maven3/bin/m2.conf" "-Dmaven.ext.class.path=/Applications/IntelliJ IDEA 2.app/Contents/plugins/maven/lib/maven-event-listener.jar" "-javaagent:/Applications/IntelliJ IDEA 2.app/Contents/lib/idea_rt.jar=58649:/Applications/IntelliJ IDEA 2.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath "/Applications/IntelliJ IDEA 2.app/Contents/plugins/maven/lib/maven3/boot/plexus-classworlds-2.6.0.jar" org.codehaus.classworlds.Launcher -Didea.version2020.1 package
[INFO] Scanning for projects...
[INFO]
[INFO] -----------------< com.naylor:dockerfile-maven-plugin >-----------------
[INFO] Building dockerfile-maven-plugin 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ dockerfile-maven-plugin ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ dockerfile-maven-plugin ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:testResources (default-testResources) @ dockerfile-maven-plugin ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin/src/test/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:testCompile (default-testCompile) @ dockerfile-maven-plugin ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.22.2:test (default-test) @ dockerfile-maven-plugin ---
[INFO]
[INFO] -------------------------------------------------------
[INFO] T E S T S
[INFO] -------------------------------------------------------
[INFO] Running com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests
13:49:50.713 [main] DEBUG org.springframework.test.context.BootstrapUtils - Instantiating CacheAwareContextLoaderDelegate from class [org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate]
13:49:50.735 [main] DEBUG org.springframework.test.context.BootstrapUtils - Instantiating BootstrapContext using constructor [public org.springframework.test.context.support.DefaultBootstrapContext(java.lang.Class,org.springframework.test.context.CacheAwareContextLoaderDelegate)]
13:49:50.762 [main] DEBUG org.springframework.test.context.BootstrapUtils - Instantiating TestContextBootstrapper for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests] from class [org.springframework.boot.test.context.SpringBootTestContextBootstrapper]
13:49:50.781 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Neither @ContextConfiguration nor @ContextHierarchy found for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests], using SpringBootContextLoader
13:49:50.785 [main] DEBUG org.springframework.test.context.support.AbstractContextLoader - Did not detect default resource location for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: class path resource [com/naylor/dockerfilemavenplugin/DockerfileMavenPluginApplicationTests-context.xml] does not exist
13:49:50.785 [main] DEBUG org.springframework.test.context.support.AbstractContextLoader - Did not detect default resource location for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: class path resource [com/naylor/dockerfilemavenplugin/DockerfileMavenPluginApplicationTestsContext.groovy] does not exist
13:49:50.785 [main] INFO org.springframework.test.context.support.AbstractContextLoader - Could not detect default resource locations for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: no resource found for suffixes {-context.xml, Context.groovy}.
13:49:50.786 [main] INFO org.springframework.test.context.support.AnnotationConfigContextLoaderUtils - Could not detect default configuration classes for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: DockerfileMavenPluginApplicationTests does not declare any static, non-private, non-final, nested classes annotated with @Configuration.
13:49:50.826 [main] DEBUG org.springframework.test.context.support.ActiveProfilesUtils - Could not find an 'annotation declaring class' for annotation type [org.springframework.test.context.ActiveProfiles] and class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]
13:49:50.926 [main] DEBUG org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider - Identified candidate component class: file [/Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin/target/classes/com/naylor/dockerfilemavenplugin/DockerfileMavenPluginApplication.class]
13:49:50.932 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Found @SpringBootConfiguration com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplication for test class com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests
13:49:51.069 [main] DEBUG org.springframework.boot.test.context.SpringBootTestContextBootstrapper - @TestExecutionListeners is not present for class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: using defaults.
13:49:51.070 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener, org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener, org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener, org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerResetTestExecutionListener, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverTestExecutionListener, org.springframework.boot.test.autoconfigure.webservices.client.MockWebServiceServerTestExecutionListener, org.springframework.test.context.web.ServletTestExecutionListener, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener, org.springframework.test.context.support.DependencyInjectionTestExecutionListener, org.springframework.test.context.support.DirtiesContextTestExecutionListener, org.springframework.test.context.transaction.TransactionalTestExecutionListener, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener, org.springframework.test.context.event.EventPublishingTestExecutionListener]
13:49:51.096 [main] DEBUG org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Skipping candidate TestExecutionListener [org.springframework.test.context.transaction.TransactionalTestExecutionListener] due to a missing dependency. Specify custom listener classes or make the default listener classes and their required dependencies available. Offending class: [org/springframework/transaction/interceptor/TransactionAttributeSource]
13:49:51.098 [main] DEBUG org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Skipping candidate TestExecutionListener [org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener] due to a missing dependency. Specify custom listener classes or make the default listener classes and their required dependencies available. Offending class: [org/springframework/transaction/interceptor/TransactionAttribute]
13:49:51.098 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Using TestExecutionListeners: [org.springframework.test.context.web.ServletTestExecutionListener@5acf93bb, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener@7e7be63f, org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener@6cd28fa7, org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener@614ca7df, org.springframework.test.context.support.DirtiesContextTestExecutionListener@4738a206, org.springframework.test.context.event.EventPublishingTestExecutionListener@66d3eec0, org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener@1e04fa0a, org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener@1af2d44a, org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerResetTestExecutionListener@18d87d80, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener@618425b5, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverTestExecutionListener@58695725, org.springframework.boot.test.autoconfigure.webservices.client.MockWebServiceServerTestExecutionListener@543588e6]
13:49:51.114 [main] DEBUG org.springframework.test.context.support.AbstractDirtiesContextTestExecutionListener - Before test class: context [DefaultTestContext@209da20d testClass = DockerfileMavenPluginApplicationTests, testInstance = [null], testMethod = [null], testException = [null], mergedContextConfiguration = [WebMergedContextConfiguration@e15b7e8 testClass = DockerfileMavenPluginApplicationTests, locations = '{}', classes = '{class com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplication}', contextInitializerClasses = '[]', activeProfiles = '{}', propertySourceLocations = '{}', propertySourceProperties = '{org.springframework.boot.test.context.SpringBootTestContextBootstrapper=true}', contextCustomizers = set[org.springframework.boot.test.context.filter.ExcludeFilterContextCustomizer@27ae2fd0, org.springframework.boot.test.json.DuplicateJsonObjectContextCustomizerFactory$DuplicateJsonObjectContextCustomizer@4278a03f, org.springframework.boot.test.mock.mockito.MockitoContextCustomizer@0, org.springframework.boot.test.web.client.TestRestTemplateContextCustomizer@2bbf180e, org.springframework.boot.test.autoconfigure.properties.PropertyMappingContextCustomizer@0, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverContextCustomizerFactory$Customizer@96def03, org.springframework.boot.test.context.SpringBootTestArgs@1], resourceBasePath = 'src/main/webapp', contextLoader = 'org.springframework.boot.test.context.SpringBootContextLoader', parent = [null]], attributes = map['org.springframework.test.context.web.ServletTestExecutionListener.activateListener' -> true]], class annotated with @DirtiesContext [false] with mode [null].
13:49:51.152 [main] DEBUG org.springframework.test.context.support.TestPropertySourceUtils - Adding inlined properties to environment: {spring.jmx.enabled=false, org.springframework.boot.test.context.SpringBootTestContextBootstrapper=true}

 .  ____     _      __ _ _
 /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/ ___)| |_)| | | | | || (_| | ) ) ) )
 ' |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::    (v2.3.4.RELEASE)

2020-10-12 13:49:51.449 INFO 16693 --- [      main] .d.DockerfileMavenPluginApplicationTests : Starting DockerfileMavenPluginApplicationTests on neiyo with PID 16693 (started by chenhd in /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin)
2020-10-12 13:49:51.451 INFO 16693 --- [      main] .d.DockerfileMavenPluginApplicationTests : No active profile set, falling back to default profiles: default
2020-10-12 13:49:52.458 INFO 16693 --- [      main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2020-10-12 13:49:52.732 INFO 16693 --- [      main] .d.DockerfileMavenPluginApplicationTests : Started DockerfileMavenPluginApplicationTests in 1.559 seconds (JVM running for 2.86)
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 2.313 s - in com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests
2020-10-12 13:49:53.042 INFO 16693 --- [extShutdownHook] o.s.s.concurrent.ThreadPoolTaskExecutor : Shutting down ExecutorService 'applicationTaskExecutor'
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO]
[INFO] --- maven-jar-plugin:3.2.0:jar (default-jar) @ dockerfile-maven-plugin ---
[INFO] Building jar: /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin/target/dockerfile-maven-plugin-0.0.1-SNAPSHOT.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:2.3.4.RELEASE:repackage (repackage) @ dockerfile-maven-plugin ---
[INFO] Replacing main artifact with repackaged archive
[INFO]
[INFO] --- dockerfile-maven-plugin:1.3.6:build (default) @ dockerfile-maven-plugin ---
[INFO] Building Docker context /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin
[INFO]
[INFO] Image will be built as com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT
[INFO]
[INFO] Step 1/5 : FROM java:8
[INFO]
[INFO] Pulling from library/java
[INFO] Digest: sha256:c1ff613e8ba25833d2e1940da0940c3824f03f802c449f3d1815a66b7f8c0e9d
[INFO] Status: Image is up to date for java:8
[INFO] ---> d23bdf5b1b1b
[INFO] Step 2/5 : EXPOSE 8080
[INFO]
[INFO] ---> Using cache
[INFO] ---> 75767466e0be
[INFO] Step 3/5 : ARG JAR_FILE
[INFO]
[INFO] ---> Using cache
[INFO] ---> 2ecdd1234dc2
[INFO] Step 4/5 : ADD target/${JAR_FILE} /app.jar
[INFO]
[INFO] ---> 6169104a5073
[INFO] Step 5/5 : ENTRYPOINT ["java", "-jar","/app.jar"]
[INFO]
[INFO] ---> Running in 23596d4612b6
[INFO] Removing intermediate container 23596d4612b6
[INFO] ---> 993715a0e72a
[INFO] Successfully built 993715a0e72a
[INFO] Successfully tagged com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT
[INFO]
[INFO] Detected build of image with id 993715a0e72a
[INFO] Building jar: /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin/target/dockerfile-maven-plugin-0.0.1-SNAPSHOT-docker-info.jar
[INFO] Successfully built com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 16.597 s
[INFO] Finished at: 2020-10-12T13:50:03+08:00
[INFO] ------------------------------------------------------------------------

重点分析一下此行后面的日志：

--- dockerfile-maven-plugin:1.3.6:build (default) @ dockerfile-maven-plugin ---

Building Docker context /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin

执行dockerfile-maven-plugin项目的docker上下文的构建

Image will be built as com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT

构建完成之后镜像的名称为：com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT

Step 1/5 : FROM java:8

dockerfile中一共定义了5步来执行构建，第一步是拉取java8的镜像，如果本地没有会从远程仓库中搜索并下载下来

Successfully tagged com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT

成功打包了镜像

引用

1：官网：https://github.com/spotify/dockerfile-maven

2：dockerfile参考：https://docs.docker.com/engine/reference/builder/

到此这篇关于dockerfile-maven-plugin极简教程的文章就介绍到这了,更多相关dockerfile-maven-plugin内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们！