Pipeline Architecture

原文：https://docs.gitlab.com/ee/ci/pipelines/pipeline_architectures.html

• Basic Pipelines
• Directed Acyclic Graph Pipelines
• Child / Parent Pipelines

Pipeline Architecture

管道是 GitLab 中 CI / CD 的基本构建块. 本页记录了一些与它们有关的重要概念.

构造管道的主要方法有三种，每种都有自己的优势. 如果需要，可以混合使用以下方法：

• 基本 ：适用于简单的项目，其中所有配置都在一个易于查找的位置.
• 有向无环图 ：适用于需要有效执行的大型，复杂项目.
• 子级/父级管道 ：适用于具有大量独立定义组件的 monorepos 和项目.

有关下面使用的任何关键字的更多详细信息，请查看我们的CI YAML 参考以获取详细信息.

Basic Pipelines

这是 GitLab 中最简单的管道. 它会在构建阶段同时运行所有内容，一旦所有这些操作完成，它将以相同的方式在测试阶段运行所有内容，依此类推. 它不是最有效的，并且如果您有很多步骤，它可能会变得非常复杂，但更易于维护：

图 LR 子图部署阶段部署-> deploy_a 部署-> deploy_b 结束子图测试阶段测试-> test_a 测试-> test_b 结束子图构建阶段构建-> build_a 构建-> build_b 结束 build_a -.->测试 build_b -.->测试 test_a -.->部署 test_b -.->部署

匹配该图的示例基本/.gitlab-ci.yml管道配置：

stages:
  - build
  - test
  - deploy
image: alpine
build_a:
  stage: build
  script:
    - echo "This job builds something."
build_b:
  stage: build
  script:
    - echo "This job builds something else."
test_a:
  stage: test
  script:
    - echo "This job tests something. It will only run when all jobs in the"
    - echo "build stage are complete."
test_b:
  stage: test
  script:
    - echo "This job tests something else. It will only run when all jobs in the"
    - echo "build stage are complete too. It will start at about the same time as test_a."
deploy_a:
  stage: deploy
  script:
    - echo "This job deploys something. It will only run when all jobs in the"
    - echo "test stage complete."
deploy_b:
  stage: deploy
  script:
    - echo "This job deploys something else. It will only run when all jobs in the"
    - echo "test stage complete. It will start at about the same time as deploy_a."

Directed Acyclic Graph Pipelines

如果效率对您很重要，并且您希望所有内容尽快运行，则可以使用有向无环图（DAG） . 使用needs关键字定义作业之间的依赖关系. 当 GitLab 知道您的工作之间的关系时，它可以尽快运行所有内容，甚至在可能的情况下跳入后续阶段.

在下面的示例中，如果build_a和test_a的速度比build_b和test_b ，则即使build_b仍在运行，GitLab 也会启动deploy_a .

使用 DAG build_a-> test_a-> deploy_a build_b-> test_b-> deploy_b 结束的图 LR 子图管道

匹配该图的示例 DAG /.gitlab-ci.yml配置：

stages:
  - build
  - test
  - deploy
image: alpine
build_a:
  stage: build
  script:
    - echo "This job builds something quickly."
build_b:
  stage: build
  script:
    - echo "This job builds something else slowly."
test_a:
  stage: test
  needs: [build_a]
  script:
    - echo "This test job will start as soon as build_a finishes."
    - echo "It will not wait for build_b, or other jobs in the build stage, to finish."
test_b:
  stage: test
  needs: [build_b]
  script:
    - echo "This test job will start as soon as build_b finishes."
    - echo "It will not wait for other jobs in the build stage to finish."
deploy_a:
  stage: deploy
  needs: [test_a]
  script:
    - echo "Since build_a and test_a run quickly, this deploy job can run much earlier."
    - echo "It does not need to wait for build_b or test_b."
deploy_b:
  stage: deploy
  needs: [test_b]
  script:
    - echo "Since build_b and test_b run slowly, this deploy job will run much later."

Child / Parent Pipelines

在上面的示例中，很明显，我们可以独立构建两种类型的东西. 这是通过trigger关键字使用” 子/父管道”的理想情况. 它将配置分成多个文件，使事情变得非常简单. 您还可以将其与：

• rules关键字 ：例如，仅在对该区域进行更改时才触发子管道.
• include关键字 ：引入常见行为，确保您不会重复自己.
• 子管道内部的DAG 管道 ，实现了两者的好处.

graph LR subgraph Parent pipeline trigger_a -.-> build_a trigger_b -.-> build_b subgraph child pipeline B build_b —> test_b —> deploy_b end subgraph child pipeline A build_a —> test_a —> deploy_a end end

匹配该图的父管道的示例/.gitlab-ci.yml配置：

stages:
  - triggers
trigger_a:
  stage: triggers
  trigger:
    include: a/.gitlab-ci.yml
  rules:
    - changes:
      - a/*
trigger_b:
  stage: triggers
  trigger:
    include: b/.gitlab-ci.yml
  rules:
    - changes:
      - b/*

例如孩子a管道配置，位于/a/.gitlab-ci.yml ，利用的 DAG needs:关键字：

stages:
  - build
  - test
  - deploy
image: alpine
build_a:
  stage: build
  script:
    - echo "This job builds something."
test_a:
  stage: test
  needs: [build_a]
  script:
    - echo "This job tests something."
deploy_a:
  stage: deploy
  needs: [test_a]
  script:
    - echo "This job deploys something."

子b管道配置示例位于/b/.gitlab-ci.yml ，利用 DAG needs:关键字：

stages:
  - build
  - test
  - deploy
image: alpine
build_b:
  stage: build
  script:
    - echo "This job builds something else."
test_b:
  stage: test
  needs: [build_b]
  script:
    - echo "This job tests something else."
deploy_b:
  stage: deploy
  needs: [test_b]
  script:
    - echo "This job deploys something else."

也可以将作业设置为在触发子管道之前或之后运行，例如，如果您具有通用的设置步骤或最后进行统一部署.