Jenkins Pipeline：在 Docker 容器内构建 Docker

Question

我正在尝试做以下事情

1. 查看代码
2. 使用其他 docker 镜像进行一些预检查（不想在 Jenkins 节点上安装这些镜像）
3. 使用docker镜像构建jarmaven:3.6-jdk-8
4. 然后运行Dockerfile构建应用程序映像
5. 将镜像推送到存储库

现在，除了在 Jenkins 节点上安装 Docker 之外，我不想安装任何东西。我想在 Docker 容器中运行完整的管道来实现这一点。我所苦恼的是如何从容器内部构建第 4 步。

我写了如下的 Jenkinsfile

pipeline {

    agent none
    
    stages {
        stage('Maven build') {
            agent {
                docker {
                    image 'maven:3.6-jdk-8'
                    args '-u root:root'
                }
            }
            steps {
                checkout(
                    [
                        $class: 'GitSCM',
                        branches: [
                            [name: '*/master']
                        ],
                        doGenerateSubmoduleConfigurations: false, 
                        extensions: [], 
                        submoduleCfg: [], 
                        userRemoteConfigs: [
                            [
                                credentialsId: '<cred-id>',
                                url: '<github-url>']
                            ]
                        ])
                        
                sh '''
                    set -eux pipefail

                    mvn -e clean install
                '''
            }
        }
        stage('Build docker image') {
             // Which docker image to use?
        }
    }
}

但我不确定如何在容器内构建docker镜像。搜索没有太大帮助。我尝试使用Jenkins节点构建docker镜像，但似乎无法混合搭配。我完全理解这是一个相当开放的问题，但我认为知道直接的答案会很有帮助。

Answer 1

我会尝试类似的事情：

pipeline {

    /*
     * Run everything on an existing agent configured with a label 'docker'.
     * This agent will need docker, git and a jdk installed at a minimum.
     */
    agent {
        node {
            label 'docker'
        }
    }

    // using the Timestamper plugin we can add timestamps to the console log
    options {
        timestamps()
    }

    environment {
        //Use Pipeline Utility Steps plugin to read information from pom.xml into env variables
        IMAGE = readMavenPom().getArtifactId()
        VERSION = readMavenPom().getVersion()
    }
    
    stages {

        stage('Clone repository') {
            /* 
             * Let's make sure we have the repository cloned to our workspace 
             */
            checkout(
                    [
                        $class: 'GitSCM',
                        branches: [
                            [name: '*/master']
                        ],
                        doGenerateSubmoduleConfigurations: false, 
                        extensions: [], 
                        submoduleCfg: [], 
                        userRemoteConfigs: [
                            [
                                credentialsId: '<cred-id>',
                                url: '<github-url>']
                            ]
                        ])
        }

        stage('Maven build') {
            agent {
                docker {
                    /*
                     * Reuse the workspace on the agent defined at top-level of
                     * Pipeline but run inside a container.
                     */
                    image 'maven:3.6-jdk-8'
                    reuseNode true
                }
            }
            steps {        
                sh '''
                    set -eux pipefail

                    mvn -e clean install
                '''
            }
            post {
                success {
                /* 
                 * Only worry about archiving the jar file 
                 * if the build steps are successful (this part may be not necessary)
                 */
                archiveArtifacts(artifacts: '**/target/*.jar', allowEmptyArchive: true)
                }
           }
        }
        stage('Build docker image') {
             steps {
                sh '''
                    docker build -t ${IMAGE} .
                    docker tag ${IMAGE} ${IMAGE}:${VERSION}
                    docker push ${IMAGE}:${VERSION}
                '''
            }
        }
    }
}

reuseNode即使签出和 Docker 构建在节点本身上运行，该选项也应该允许您在容器中运行 maven 构建。请参阅文档这里。