Monorepo 按需构建

381 字约 1 分钟

本文介绍如何在 Monorepo 中实现按需构建——仅修改特定目录时触发对应服务的构建任务，避免全量构建的资源浪费。

前置知识

语法手册：Pipeline.ifModify
系统默认环境变量：CNB_PIPELINE_KEY

配置文件示例

多个包可采用统一模板 + 变量区分的方式，避免复制粘贴：

.cnb.yml
main:
  push:
    package-1:
      services:
        - docker
      ifModify:
        - packages/package-1/**
      env:
        PACKAGE: package-1
      stages:
        - name: set docker tag
          script: echo -n "${CNB_DOCKER_REGISTRY}/${CNB_REPO_SLUG_LOWERCASE}:$CNB_COMMIT_SHORT"
          exports:
            info: IMAGE_TAG
        - name: docker build
          script: cd packages/$PACKAGE && docker build -t $IMAGE_TAG .
        - name: push image
          script: docker push $IMAGE_TAG
    package-2:
      services:
        - docker
      ifModify:
        - packages/package-2/**
      env:
        PACKAGE: package-2
      stages:
        - name: set docker tag
          script: echo -n "${CNB_DOCKER_REGISTRY}/${CNB_REPO_SLUG_LOWERCASE}:$CNB_COMMIT_SHORT"
          exports:
            info: IMAGE_TAG
        - name: docker build
          script: cd packages/$PACKAGE && docker build -t $IMAGE_TAG .
        - name: push image
          script: docker push $IMAGE_TAG

当包数量较多时，推荐通过 include 将通用 stages 抽为模板文件，每个包仅需声明 ifModify 和 env 即可复用。

假设通用构建步骤抽为 cnb/build-template.yml：

cnb/build-template.yml
stages:
  - name: set docker tag
    script: echo -n "${CNB_DOCKER_REGISTRY}/${CNB_REPO_SLUG_LOWERCASE}:$CNB_COMMIT_SHORT"
    exports:
      info: IMAGE_TAG
  - name: docker build
    script: cd packages/$PACKAGE && docker build -t $IMAGE_TAG .
  - name: push image
    script: docker push $IMAGE_TAG

主配置通过 include 引入模板，每个包只需关注差异部分：

.cnb.yml
main:
  push:
    package-1:
      services:
        - docker
      ifModify:
        - packages/package-1/**
      env:
        PACKAGE: package-1
      include: cnb/build-template.yml
    package-2:
      services:
        - docker
      ifModify:
        - packages/package-2/**
      env:
        PACKAGE: package-2
      include: cnb/build-template.yml