Dependabot's PRs do not pass our GitHub actions

[flandia]

Refer to: #20

[polyipseity]

It works on https://github.com/USThing/api-campus-services/pull/47.

The successful one has push: ${{ github.ref == 'refs/heads/main' && github.event_name != 'pull_request' }} while here we have push: true.

https://github.com/USThing/api-campus-services/blob/2500637cd2d0177767c8ddc99b48b0c63e850c2f/.github/workflows/docker.yml#L48

template-api/.github/workflows/docker.yml

Line 52 in b7131b9

push: true

I have looked up some docs quickly and find this on https://docs.github.com/en/actions/security-for-github-actions/security-guides/automatic-token-authentication#permissions-for-the-github_token:

Workflow runs triggered by Dependabot pull requests run as if they are from a forked repository, and therefore use a read-only GITHUB_TOKEN. These workflow runs cannot access any secrets. For information about strategies to keep these workflows secure, see Security hardening for GitHub Actions.

I think the correct way to fix this is to specify the permissions explicitly (example from https://docs.github.com/en/actions/use-cases-and-examples/publishing-packages/publishing-docker-images#publishing-images-to-github-packages):

    permissions:
      contents: read
      packages: write
      attestations: write
      id-token: write

And then we should probably change the file on https://github.com/USThing/api-campus-services (and other repo following this template) to use push: true.

[flandia]

Thanks for the suggestion! Can the bot be granted permission to push containers if we explicitly specify the permission?

[polyipseity]

I think yes, because the permissions there should be the default permissions (The following table shows the permissions granted to the GITHUB_TOKEN by default.) if we don't specify the permissions explicitly.

Actually this section should answer the question: https://docs.github.com/en/actions/security-for-github-actions/security-guides/automatic-token-authentication#how-the-permissions-are-calculated-for-a-workflow-job

The permissions for the GITHUB_TOKEN are initially set to the default setting for the enterprise, organization, or repository. If the default is set to the restricted permissions at any of these levels then this will apply to the relevant repositories. For example, if you choose the restricted default at the organization level then all repositories in that organization will use the restricted permissions as the default. The permissions are then adjusted based on any configuration within the workflow file, first at the workflow level and then at the job level. Finally, if the workflow was triggered by a pull request from a forked repository, and the Send write tokens to workflows from pull requests setting is not selected, the permissions are adjusted to change any write permissions to read only.

The wordings seem to indicate that the setting Send write tokens to workflows from pull requests needs to be enabled as well (aside from specifying the permissions explicitly), since previously it said "workflow runs triggered by Dependabot pull requests run as if they are from a forked repository". But you can try to compare enabling and not enabling that setting first and see if it works.

[polyipseity]

Fixed with bc25301, e.g. see #29.