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Understanding GitHub Actions

Learn the basics of GitHub Actions, including core concepts and essential terminology.

注意:GitHub Enterprise Server 目前不支持 GitHub 托管的运行器。 可以在 GitHub public roadmap 上查看有关未来支持计划的更多信息。


GitHub Actions 是一种持续集成和持续交付 (CI/CD) 平台,可用于自动执行生成、测试和部署管道。 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.

You must host your own Linux, Windows, or macOS virtual machines to run workflows for your GitHub Enterprise Server instance. 自承载运行器可以是物理设备、虚拟设备、在容器中、在本地或在云中。

For more information about introducing GitHub Actions to your enterprise, see "Introducing GitHub Actions to your enterprise."

The components of GitHub Actions

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.

Workflow overview


工作流程是一个可配置的自动化过程,它将运行一个或多个作业。 工作流程由签入到存储库的 YAML 文件定义,并在存储库中的事件触发时运行,也可以手动触发,或按定义的时间表触发。

工作流程在存储库的 .github/workflows 目录中定义,存储库可以有多个工作流程,每个工作流程都可以执行不同的任务集。 例如,您可以有一个工作流程来构建和测试拉取请求,另一个工作流程用于在每次创建发布时部署应用程序,还有一个工作流程在每次有人打开新议题时添加标签。

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


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.

For a complete list of events that can be used to trigger workflows, see Events that trigger workflows.


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."


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.

For more information, see "Creating actions."


运行程序是触发工作流时运行工作流的服务器。 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."

Create an example workflow

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 named .github/workflows.

You can create an example workflow in your repository that automatically triggers a series of commands whenever code is pushed. In this workflow, GitHub Actions checks out the pushed code, installs the bats testing framework, and runs a basic command to output the bats version: bats -v.

  1. In your repository, create the .github/workflows/ directory to store your workflow files.

  2. In the .github/workflows/ directory, create a new file called learn-github-actions.yml and add the following code.

    name: learn-github-actions
    on: [push]
        runs-on: ubuntu-latest
          - uses: actions/checkout@v2
          - uses: actions/setup-node@v2
              node-version: '14'
          - run: npm install -g bats
          - run: bats -v
  3. Commit these changes and push them to your GitHub repository.

Your new GitHub Actions workflow file is now installed in your repository and will run automatically each time someone pushes a change to the repository. To see the details about a workflow's execution history, see "Viewing the activity for a workflow run."

Understanding the workflow file

To help you understand how YAML syntax is used to create a workflow file, this section explains each line of the introduction's example:

name: learn-github-actions
Optional - The name of the workflow as it will appear in the "Actions" tab of the GitHub repository.
on: [push]
Specifies the trigger for this workflow. This example uses the push event, so a workflow run is triggered every time someone pushes a change to the repository or merges a pull request. This is triggered by a push to every branch; for examples of syntax that runs only on pushes to specific branches, paths, or tags, see "Workflow syntax for GitHub Actions."
Groups together all the jobs that run in the learn-github-actions workflow.
Defines a job named check-bats-version. The child keys will define properties of the job.
  runs-on: ubuntu-latest
Configures the job to run on the latest version of an Ubuntu Linux runner. This means that the job will execute on a fresh virtual machine hosted by GitHub. For syntax examples using other runners, see "Workflow syntax for GitHub Actions."
Groups together all the steps that run in the check-bats-version job. Each item nested under this section is a separate action or shell script.
    - uses: actions/checkout@v2
The uses keyword specifies that this step will run v3 of the actions/checkout action. This is an action that checks out your repository onto the runner, allowing you to run scripts or other actions against your code (such as build and test tools). You should use the checkout action any time your workflow will run against the repository's code.
    - uses: actions/setup-node@v2
        node-version: '14'
This step uses the actions/setup-node@v2 action to install the specified version of the Node.js (this example uses v14). This puts both the node and npm commands in your PATH.
    - run: npm install -g bats
The run keyword tells the job to execute a command on the runner. In this case, you are using npm to install the bats software testing package.
    - run: bats -v
Finally, you'll run the bats command with a parameter that outputs the software version.

Visualizing the workflow file

In this diagram, you can see the workflow file you just created and how the GitHub Actions components are organized in a hierarchy. Each step executes a single action or shell script. Steps 1 and 2 run actions, while steps 3 and 4 run shell scripts. To find more prebuilt actions for your workflows, see "Finding and customizing actions."

Workflow overview

Viewing the activity for a workflow run

When your workflow is triggered, a workflow run is created that executes the workflow. After a workflow run has started, you can see a visualization graph of the run's progress and view each step's activity on GitHub.

  1. 在 your GitHub Enterprise Server instance 上,导航到存储库的主页。

  2. Under your repository name, click Actions.

    Navigate to repository

  3. In the left sidebar, click the workflow you want to see.

    Screenshot of workflow results

  4. Under "Workflow runs", click the name of the run you want to see.

    Screenshot of workflow runs

  5. Under Jobs or in the visualization graph, click the job you want to see.

    Select job

  6. View the results of each step.

    Screenshot of workflow run details

More complex examples

有关演示 GitHub Actions 更复杂功能的示例,请参阅“示例”。 你可以看到一些详细示例,这些示例说明如何在运行器上测试代码、访问 GitHub CLI 以及使用高级功能(如并发和测试矩阵)。

Next steps

Contacting support

如果需要任何与工作流配置相关的帮助,比如语法、GitHub 托管的运行器或生成操作,请在 GitHub Community 的 GitHub Actions 和 GitHub Packages 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 GitHub Actions GitHub 社区讨论 中分享。

如有以下任意情况,无论您的使用或预期使用是否属于使用限制类别,都请联系 你的网站管理员:

  • 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
  • 如果你遇到与预期矛盾现有行为,但不一定是文件记录的情况。

Further reading