ACT Setup for Local Testing of Github Actions

Setting Up Local Testing of GitHub Actions

Testing GitHub Actions locally can help speed up your development process by avoiding frequent pushes to GitHub.

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1. Prerequisites

Before you begin, ensure you have the following installed:

• Git: Download Git
• Docker: Install Docker
• act CLI: act is a tool to run GitHub Actions locally.
  • Install via Homebrew (macOS/Linux):

    brew install act

  • Install on other platforms: act GitHub Repository

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2. Installing act

1. Verify installation by running:

   act --version

2. If act is not found, ensure your PATH includes the directory where act is installed.

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3. Setting Up Your Repository

Ensure your GitHub Actions workflows are in the .github/workflows/ directory of your repository. If no workflows exist, create a new file, e.g., .github/workflows/test.yml.

Example workflow file:

name: CI Test
 
on:
  push:
    branches:
      - main
 
jobs:
  build:
    runs-on: ubuntu-latest
 
    steps:
      - uses: actions/checkout@v3
      - name: Run a sample command
        run: echo "Hello, World!"

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4. Configuring act

4.1 Choosing a Docker Image

act uses Docker images to simulate GitHub Actions runners. Use the -P flag to specify a platform (e.g., ubuntu-latest).

Example:

act -P ubuntu-latest=nektos/act-environments-ubuntu:18.04

You can also configure default images by creating a .actrc file in your home directory:

-P ubuntu-latest=nektos/act-environments-ubuntu:18.04

4.2 Providing Secrets

If your workflow uses secrets, define them in a .secrets file:

MY_SECRET=supersecretvalue

Run act with:

act -s MY_SECRET=supersecretvalue

Alternatively, load secrets from the .secrets file:

act --secret-file .secrets

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5. Running act

Navigate to your repository and execute act:

act

Common Flags

• -j: Run a specific job.

  act -j build

• -e: Use a specific event file.

  act -e event.json

• -n: Dry run (no actions are executed).

  act -n

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6. Debugging and Logs

To view detailed logs:

act -v

If a workflow fails, act will output error messages and stack traces for debugging.

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7. Limitations of act

• AWS OIDC does not seem to work with act. Might be added in the future. Just test once and see if it works. Do not spend time on this. Deploy to GitHub and test the OIDC authentication there.

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By following these steps, you can effectively test and debug GitHub Actions workflows locally, saving time and improving reliability.