Get GitHub Action registration token for self-hosted runners

Synopsis

To create a self-hosted GitHub Runner it is needed to run a custom script provided by GitHub which registers a machine as a Runner. For that registration a registration token is needed. You can obtain such token manually in the Settings menu of a repository (or organization).
However I needed a solution where I can fully automate the process of Runner deployment so I needed a way to automate token retrieval too.

This GitHub Action retrives a registration token via Octokit API so you can use it on your GitHub Action workflow.

Usage

It is possible to create self-hosted runners for a specific repository or an organization. In latter case every repository of the given organization can utilize the runner. This action acquires a registration token based on the scope of your Personal Access Token (PAT). If your PAT have scopes of both repo and admin:org, this action will provide a registration token that can be used for organization level registration. However, if the repository does not belongs to an organization it will never acquire an organization level token. You have to place your PAT to GitHub Secrets of your repository. In case you want to specify the scope for some reason, you can do it by providing the scope in the action.

(One could ask the question: Is it possible to use this with secrets.GITHUB_TOKEN? Unfortunately it is not possible! GITHUB_TOKEN has repository level scope, so it can't be used to create organization level runner registration. Furthermore, this token has no privilage to acquire repository level registration token neither.)

Inputs

scope

Specify scope of registration token. Possible values: automatic, organization or repository Default: automatic

token (required)

A Personal Access Token (PAT) with the full scope of repo OR admin:org.

Outputs

expires_at

The expiration time of the token (usually it expires in one hour).

token

The runner registration token (in the scope provided in input paramaters).

Example usage

- name: Get token for self-hosted runner registration
  uses: roncsak/[email protected]
  id  : runnerRegistration 
  with:
    token: ${{ secrets.PAT }}

- name: Use the token in subsequent steps
  run : |
    echo ${{ steps.runnerRegistration.outputs.token }}
    echo "Your token expires at: ${{ steps.runnerRegistration.outputs.expires_at }}"