This GitHub Action deploys using Kamal. Supports Kamal v2.0 and later.

To update the README to reflect the optional environment input, you can modify the usage section to indicate that environment is no longer required and explain how the action behaves when environment is omitted.

Here's how the README might look:

This GitHub Action deploys your application using Kamal and handles cancellation gracefully.

Note: Only registry-username and registry-password are required. Any other necessary configuration, such as DATABASE_URL, REDIS_URL, and RAILS_MASTER_KEY, should be provided as environment variables in the workflow file.

steps:
  - name: Kamal Deploy
    uses: igor-alexandrov/kamal-deploy@v0.1.3
    with:
      # environment: 'staging'  # Optional, only used if provided
      registry-username: ${{ secrets.KAMAL_REGISTRY_USERNAME }}
      registry-password: ${{ secrets.KAMAL_REGISTRY_PASSWORD }}
    env:
      DATABASE_URL: ${{ secrets.DATABASE_URL }}
      REDIS_URL: ${{ secrets.REDIS_URL }}
      RAILS_MASTER_KEY: ${{ secrets.RAILS_MASTER_KEY }}