Use the latest version of Trufflehog, and use the checkout provided by the GitHub Action checkout step

[zbuc]

If you set up your Trufflehog action to use a checkout step, you can use the checkout exposed to the repo as a volume rather than having to check out the code repository in the container.

Example config:

jobs:
  trufflehog:
    runs-on: ubuntu-latest
    name: Trufflehog
    steps:
      - uses: actions/checkout@v2

      - name: Extract branch name
        shell: bash
        run: echo "##[set-output name=branch;]$(echo ${GITHUB_REF#refs/heads/})"
        id: extract_branch

      - name: trufflehog-actions-scan
        uses: dopplerhq/trufflehog-actions-scan@master
        with:
          scanArguments: "--regex --max_depth=50 --branch=${{ steps.extract_branch.outputs.branch }} --entropy=False --allow=/github/workspace/.trufflehog/allow --exclude_paths=/github/workspace/.trufflehog/exclude_patterns"

Additionally I updated this to use the latest version of trufflehog which supports additional features like the --allow flag.