Docker：使用 Maven 插件构建镜像

• 通过 Maven 的 Docker 插件可以构建 Docker 镜像

快速入门

• 在 pom.xml 中添加 Docker 插件

<plugin>
    <groupId>com.spotify</groupId>
    <artifactId>docker-maven-plugin</artifactId>
    <version>0.4.13</version>
    <configuration>
        <imageName>linyuantongxue/docker-demo:0.0.1</imageName> // 指定镜像名称，linyuantongxue  是仓库名称（对应 DockerHub 用户名），docker-demo 是镜像名称（对应 DockerHub 仓库名），0.0.1 是标签名称（相当于版本号）        <baseImage>java</baseImage>     // 指定基础镜像，等同 FROM 指令        <entryPoint>["java","-jar","app.jar"]</entryPoint>       // 等同于 ENTRYPOINT 指令        <resources>
            <resource>
                <targetPath>/</targetPath>  
                <directory>${project.build.directory}</directory>   // 指定要复制的根目录，${project.build.directory} 表示 target 目录                <include>${project.build.finalName}.jar</include>   // 指定要复制的文件，${project.build.finalName}.jar 指打包后的 jar 文件            </resource>
        </resources>
    </configuration></plugin>

• 执行以下命令构建 Docker 镜像

mvn clean package docker:build

• 执行 docker images 查看刚才构建的镜像

读取 Dockerfile 文件

• 读取 Dockerfile 文件就不必指定 baseImage 和 entrypoint

<plugin>
    <groupId>com.spotify</groupId>
    <artifactId>docker-maven-plugin</artifactId>
    <version>0.4.13</version>
    <configuration>
        <dockerDirectory>${project.basedir}/src/main/docker</dockerDirectory>     // 指定要读取的 Dockerfile 文件        <imageName>linyuantongxue/docker-demo:0.0.1</imageName>  // 指定镜像名称，linyuantongxue  是仓库名称（对应 DockerHub 用户名），docker-demo 是镜像名称（对应 DockerHub 仓库名），0.0.1 是标签名称（相当于版本号）        <resources>
            <resource>
                <targetPath>/</targetPath>  
                <directory>${project.build.directory}</directory>   // 指定要复制的根目录，${project.build.directory} 表示 target 目录                <include>${project.build.finalName}.jar</include>   // 指定要复制的文件，${project.build.finalName}.jar 指打包后的 jar 文件            </resource>
        </resources>
    </configuration></plugin>

将插件绑定在某个 phase 执行

• 很多场景下有这样的需求，比如执行 mvn clean package 时插件就自动构建 Docker 镜像，要实现这点只需要将插件的 goal 绑定在某个 phase 即可

• maven 命令格式是：mvn phase:goal，phase 绑定了目标的构建生命周期阶段，goal 配置的执行目标

• 只需添加如下配置：

<plugin>
    <groupId>com.spotify</groupId>
    <artifactId>docker-maven-plugin</artifactId>
    <version>0.4.13</version>
    // 在 maven 生命周期 package 中执行 build 构建目标    <executions>
        <execution>
            <id>build-image</id>
            <phase>package</phase>
            <goals>
                <goal>build</goal>
            </goals>
        </execution>
    </executions>
    // $$$$$$$$$$$$$$$$华丽的分割线$$$$$$$$$$$$$$$$    <configuration>
        <imageName>linyuantongxue/docker-demo:0.0.1</imageName>
        <baseImage>java</baseImage>
        <entryPoint>["java","-jar","app.jar"]</entryPoint>
        <resources>
            <resource>
                <targetPath>/</targetPath>
                <directory>${project.build.directory}</directory>
                <include>${project.build.finalName}.jar</include>
            </resource>
        </resources>
    </configuration></plugin>

推送镜像

• 使用 Maven 插件也可以推送镜像到 Docker Hub

• 修改 Maven 全局配置信息文件 settings.xml，配置 Docker Hub 用户信息

<servers>
    <server>
        <id>docker-hub</id>
        # DockerHub 该网站的用户名必须全部为小写才正确        <username>linyuantongxue</username>
        <password>765371578Ly</password>
        <configuration>
            <email>765371578@qq.com</email>
        </configuration>
    </server></servers>

• 修改 pom 文件

<plugin>
    <groupId>com.spotify</groupId>
    <artifactId>docker-maven-plugin</artifactId>
    <version>0.4.13</version>
    <configuration>
        <imageName>linyuantongxue/docker-demo:0.0.1</imageName>
        <baseImage>java</baseImage>
        <entryPoint>["java","-jar","app.jar"]</entryPoint>
        <resources>
            <resource>
                <targetPath>/</targetPath>
                <directory>${project.build.directory}</directory>
                <include>${project.build.finalName}.jar</include>
            </resource>
        </resources>
        <!--与配置文件 setting.xml 中的 server.id 一致，用于推送镜像-->
        <serverId>docker-hub</serverId>
    </configuration></plugin>

• 执行以下命令，添加 pushImage 标识，表示推送镜像

mvn clean package docker:build -DpushImage

• 上面例子中通过 imageName 指定镜像名称和标签，也可以借助 imageTags 元素更为灵活的指定镜像名称和标签，这样就可以为同一个镜像指定两个标签

<configuration>
    <imageName>linyuantongxue/docker-demo</imageName>
    <imageTags>
        <imageTag>0.0.1</imageTag>
        <imageTag>latest</imageTag>
    </imageTags></configuration>

• 也可在构建命令时使用 dockerImageTags 参数指定标签名称

mvn clean package:build -DpushImageTags -DdockerImageTags=latest -DdockerImageTags=another-tag

• 若需要重复构建相同标签名称的镜像，可将 forceTags 设置为 true

<configuration>
    // .......    <forceTags>true</forceTags></configuration>

作者：林塬
链接：https://www.jianshu.com/p/c9d771a193b4