メモ
GitHub ホステッド ランナーは、現在 GitHub Enterprise Server ではサポートされていません。 GitHub public roadmap で、今後の計画的なサポートの詳細を確認できます。
About custom actions
You can create actions by writing custom code that interacts with your repository in any way you'd like, including integrating with GitHub's APIs and any publicly available third-party API. For example, an action can publish npm modules, send SMS alerts when urgent issues are created, or deploy production-ready code.
Actions can run directly on a machine or in a Docker container. You can define an action's inputs, outputs, and environment variables.
Types of actions
メモ
You can build Docker container, JavaScript, and composite actions. Actions require a metadata file to define the inputs, outputs, and runs configuration for your action. Action metadata files use YAML syntax, and the metadata filename must be either action.yml or action.yaml. The preferred format is action.yml.
| Type | Linux | macOS | Windows |
|---|---|---|---|
| Docker container | |||
| JavaScript | |||
| Composite Actions |
Docker container actions
Docker containers package the environment with the GitHub Actions code. This creates a more consistent and reliable unit of work because the consumer of the action does not need to worry about the tools or dependencies.
A Docker container allows you to use specific versions of an operating system, dependencies, tools, and code. For actions that must run in a specific environment configuration, Docker is an ideal option because you can customize the operating system and tools. Because of the latency to build and retrieve the container, Docker container actions are slower than JavaScript actions.
Docker container actions can only execute on runners with a Linux operating system. セルフホストランナーでDockerコンテナアクションを実行するためには、Linuxオペレーティングシステムを使い、Dockerがインストールされていなければなりません。 自己ホストランナーの要件の詳細については、「Self-hosted runners」を参照してください。
JavaScript actions
JavaScript actions can run directly on a runner machine, and separate the action code from the environment used to run the code. Using a JavaScript action simplifies the action code and executes faster than a Docker container action.
JavaScriptのアクションがGitHubがホストするすべてのランナー（Ubuntu、Windows、macOS）と互換性があることを保証するためには、作成するパッケージ化されたJavaScriptのコードは純粋なJavaScriptであり、他のバイナリに依存していてはなりません。 JavaScript のアクションはランナー上で直接実行され、ランナー イメージ内に既に存在するバイナリを利用します。
If you're developing a Node.js project, the GitHub Actions Toolkit provides packages that you can use in your project to speed up development. For more information, see the actions/toolkit repository.
Composite Actions
A composite action allows you to combine multiple workflow steps within one action. For example, you can use this feature to bundle together multiple run commands into an action, and then have a workflow that executes the bundled commands as a single step using that action. To see an example, check out 複合アクションを作成する.
Next steps
To learn about how to manage your custom actions, see Managing custom actions.