Understanding GitHub Actions

概览

GitHub Actions is a continuous integration and continuous delivery (CI/CD) platform that allows you to automate your build, test, and deployment pipeline. You can create workflows that build and test every pull request to your repository, or deploy merged pull requests to production.

GitHub Actions goes beyond just DevOps and lets you run workflows when other events happen in your repository. For example, you can run a workflow to automatically add the appropriate labels whenever someone creates a new issue in your repository.

GitHub provides Linux, Windows, and macOS virtual machines to run your workflows, or you can host your own self-hosted runners in your own data center or cloud infrastructure.

GitHub Actions 的组件

You can configure a GitHub Actions workflow to be triggered when an event occurs in your repository, such as a pull request being opened or an issue being created. Your workflow contains one or more jobs which can run in sequential order or in parallel. Each job will run inside its own virtual machine runner, or inside a container, and has one or more steps that either run a script that you define or run an action, which is a reusable extension that can simplify your workflow.

工作流程

A workflow is a configurable automated process that will run one or more jobs. Workflows are defined by a YAML file checked in to your repository and will run when triggered by an event in your repository, or they can be triggered manually, or at a defined schedule.

Your repository can have multiple workflows in a repository, each of which can perform a different set of steps. For example, you can have one workflow to build and test pull requests, another workflow to deploy your application every time a release is created, and still another workflow that adds a label every time someone opens a new issue.

For more information about workflows, see "Using workflows."

事件

An event is a specific activity in a repository that triggers a workflow run. For example, activity can originate from GitHub when someone creates a pull request, opens an issue, or pushes a commit to a repository. You can also trigger a workflow run on a schedule, by posting to a REST API, or manually.

有关可用于触发工作流程的事件的完整列表，请参阅触发工作流程的事件。

Jobs

A job is a set of steps in a workflow that execute on the same runner. Each step is either a shell script that will be executed, or an action that will be run. Steps are executed in order and are dependent on each other. Since each step is executed on the same runner, you can share data from one step to another. For example, you can have a step that builds your application followed by a step that tests the application that was built.

You can configure a job's dependencies with other jobs; by default, jobs have no dependencies and run in parallel with each other. When a job takes a dependency on another job, it will wait for the dependent job to complete before it can run. For example, you may have multiple build jobs for different architectures that have no dependencies, and a packaging job that is dependent on those jobs. The build jobs will run in parallel, and when they have all completed successfully, the packaging job will run.

For more information about jobs, see "Using jobs."

操作

An action is a custom application for the GitHub Actions platform that performs a complex but frequently repeated task. Use an action to help reduce the amount of repetitive code that you write in your workflow files. An action can pull your git repository from GitHub, set up the correct toolchain for your build environment, or set up the authentication to your cloud provider.

You can write your own actions, or you can find actions to use in your workflows in the GitHub Marketplace.

更多信息请参阅“创建操作”。

运行器

A runner is a server that runs your workflows when they're triggered. Each runner can run a single job at a time. You must host your own runners for GitHub Enterprise Server. For more information, see "Hosting your own runners."

创建示例工作流程

GitHub Actions uses YAML syntax to define the workflow. Each workflow is stored as a separate YAML file in your code repository, in a directory called .github/workflows.

您可以在仓库中创建示例工作流程，只要推送代� �，该工作流程就会自动触发一系列命令。 在此工作流程中，GitHub Actions 检出推送的代� �，安装软件依赖项，并运行 -v。

1. 在您的仓库中，创建 .github/workflows/ 目录来存储工作流程文件。
2. 在 .github/workflows/ 目录中，创建一个名为 learn-github-actions.yml 的新文件并添� 以下代� �。

   name: learn-github-actions
   on: [push]
   jobs:
     check-bats-version:
       runs-on: ubuntu-latest
       steps:
         - uses: actions/checkout@v2
         - uses: actions/setup-node@v2
           with:
             node-version: '14'
         - run: npm install -g bats
         - run: bats -v
   

3. 提交这些更改并将其推送到您的 GitHub 仓库。

您的新 GitHub Actions 工作流程文件现在安装在您的仓库中，每次有人推送更改到仓库时都会自动运行。 有关作业的执行历史记录的详细信息，请参阅“查看工作流程的活动”。

了解工作流程文件

为帮助您了解如何使用 YAML 语法来创建工作流程文件，本节解释介绍示例的每一行：

name: learn-github-actions

on: [push]

jobs:

check-bats-version:

  runs-on: ubuntu-latest

  steps:

    - uses: actions/checkout@v2

    - uses: actions/setup-node@v2
      with:
        node-version: '14'

    - run: npm install -g bats

    - run: bats -v

可视化工作流程文件

在此关系图中，您可以看到刚刚创建的工作流程文件，以及 GitHub Actions 组件在层次结构中的组织方式。 Each step executes a single action or shell script. Steps 1 and 2 run actions, while steps 3 and 4 run shell scripts. 要查找更多为工作流预构建的操作，请参阅“查找和自定义操作”。

Viewing the workflow's activity

Once your workflow has started running, you can view each step's activity on GitHub.

1. 在 your GitHub Enterprise Server instance 上，导航到仓库的主页面。

2. 在仓库名称下，单击 Actions（操作）。

3. 在左侧边� �中，单击您想要查看的工作流程。

4. 在“Workflow runs（工作流程运行）”下，单击您想要查看的运行的名称。

5. 单击作业名称以查看每个步骤的结果。

后续步骤

要继续了解 GitHub Actions，请参阅“查找和自定义操作”。

To understand how billing works for GitHub Actions, see "About billing for GitHub Actions".

联系支持

如果需要任何与工作流程配置相关的帮助，比如语法、GitHub 托管的运行器或构建操作，请在 GitHub Community Support 的 GitHub Actions 类别中查找现有主题或发起一个新主题。

如果您有对 GitHub Actions 的反馈或功能请求，请在 Feedback discussion for GitHub Actions 中分享。

如有以下任意情况，� 论您的使用或预期使用是否属于使用限制类别，都请联系 your site administrator：

• 如果您认为您的帐户受到不正确的限制
• 如果您在执行您的操作之一时遇到意外错误，例如：唯一的 ID
• 如果� 遇到与预期矛盾现有行为，但不一定是文件记录的情况。

延伸阅读

• "About GitHub Actions for enterprises"