docs/content/actions/creating-actions/developing-a-third-party-cli-action.md

title, shortTitle, intro, redirect_from, versions, type, topics

title	shortTitle	intro	redirect_from	versions	type	topics
Developing a third party CLI action	CLI setup action	Learn how to develop an action to set up a CLI on {% data variables.product.prodname_actions %} runners.		fpt ghec * *	tutorial	Actions

Introduction

You can write an action to provide a way for users to access your servers via a configured CLI environment on {% data variables.product.prodname_actions %} runners.

Your action should:

• Make it simple for users to specify the version of the CLI to install
• Support multiple operating systems
• Run in an efficient fashion to minimize run-time and associated costs
• Work across {% data variables.product.product_name %}-hosted and self-hosted runners
• Leverage community tooling when possible

This article will demonstrate how to write an action that retrieves a specific version of your CLI, installs it, adds it to the path, and (optionally) caches it. This type of action (an action that sets up a tool) is often named setup-$TOOL.

Prerequisites

You should have an understanding of how to write a custom action. For more information, see "AUTOTITLE". For a more detailed guide on how to write a custom action, see "AUTOTITLE."

Example

The following script demonstrates how you can get a user-specified version as input, download and extract the specific version of your CLI, then add the CLI to the path.

{% data variables.product.prodname_dotcom %} provides actions/toolkit, which is a set of packages that helps you create actions. This example uses the actions/core and actions/tool-cache packages.

{% raw %}

const core = require('@actions/core');
const tc = require('@actions/tool-cache');

async function setup() {
  // Get version of tool to be installed
  const version = core.getInput('version');

  // Download the specific version of the tool, e.g. as a tarball
  const pathToTarball = await tc.downloadTool(getDownloadURL());

  // Extract the tarball onto the runner
  const pathToCLI = await tc.extractTar(pathToTarball);

  // Expose the tool by adding it to the PATH
  core.addPath(pathToCLI)
}

module.exports = setup

{% endraw %}

To use this script, replace getDownloadURL with a function that downloads your CLI. You will also need to create an actions metadata file (action.yml) that accepts a version input and that runs this script. For full details about how to create an action, see "AUTOTITLE."

Further reading

This pattern is employed in several actions. For more examples, see:

• ruby/setup-ruby
• google-github-actions/setup-gcloud
• hashicorp/setup-terraform