The action sets up and caches the latest release of fossa-cli, infer the correct configuration from the current system state, analyze the project for a list of its dependencies, and upload the results to FOSSA.

This action aims to provide an OS-neutral interface to fossa-cli, and so will not add features that only work on one operating system. It will also track the latest release of fossa-cli.

If you are an open-source project maintainer, you probably want to check pull requests from external contributors with FOSSA, but it's impossible to do with secrets when the workflow runs on the pull request event due to GitHub's constraints. However, FOSSA has the push-only API token, allowing you to safely check pull requests.

There is no problem with this:

- name: Run FOSSA scan and upload build data
  uses: fossa-contrib/fossa-action@v3
  with:
    fossa-api-key: abcdefghijklmnopqrstuvwxyz
  #                ^^^^^^^^^^^^^^^^^^^^^^^^^^

This will cause an error on the pull request event:

- name: Run FOSSA scan and upload build data
  uses: fossa-contrib/fossa-action@v3
  with:
    fossa-api-key: ${{ secrets.FOSSA_API_KEY }}
  #                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

• https://docs.fossa.com/docs/api-reference#push-only-api-token
• https://securitylab.github.com/research/github-actions-preventing-pwn-requests

There is a point that is particularly easy to misunderstand. It's where you specify the version of the action itself.

- name: Run FOSSA scan and upload build data
  uses: fossa-contrib/fossa-action@v3
  #                               ^^^
  with:
    fossa-api-key: abcdefghijklmnopqrstuvwxyz

We recommend that you include the version of the action. We adhere to semantic versioning, it's safe to use the major version (v1) in your workflow. If you use the master branch, this could break your workflow when we publish a breaking update and increase the major version.

steps:
  # Reference the major version of a release (most recommended)
  - uses: fossa-contrib/fossa-action@v3
  # Reference a specific commit (most strict)
  - uses: fossa-contrib/fossa-action@cdc5065
  # Reference a semver version of a release (not recommended)
  - uses: fossa-contrib/fossa-action@v3.0.0
  # Reference a branch (most dangerous)
  - uses: fossa-contrib/fossa-action@master

name: License Scanning

on:
  - pull_request
  - push

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout tree
        uses: actions/checkout@v4

      - name: Run FOSSA scan and upload build data
        uses: fossa-contrib/fossa-action@v3
        with:
          fossa-api-key: abcdefghijklmnopqrstuvwxyz

• fossa-api-key: This input is used to upload the results of the build analysis.
• github-token: This input is used to get the latest release of fossa-cli from GitHub API.
• endpoint: This input is used to specify which fossa endpoint to use.
• skip-test: This input is used to specify whether to execute fossa test. This takes a long time, so it's set to true by default.