GitHub Actions overrides provisioner user in molecule test

Question

I have a project that utilizes Molecule for testing, and I've configured my molecule.yml file to use an unprivileged user (already created on the image pushed to a registry) named molecule during provisioning:

provisioner:
  name: ansible
  connection_options:
    ansible_ssh_user: molecule

I added a small playbook that reproduces the error on Github Actions https://github.com/staticdev/nix-playbook/tree/feature/enable-flakes, it basically install nix package manager with [Ableton/nix role].

When I run molecule test locally, everything works as expected and the provisioning process executes with the molecule user. However, when I push my code to GitHub and trigger the same command in a GitHub Actions workflow, it runs the test with a user named runner, causing issues in my tests.

Why does this override occur specifically in the GA environment and is there a way to bypass or override this behavior? I tried to find something in GA documentation and searching on internet but found nothing relevant.

---

UPDATE: the initial config I was previously trying an is old way to configure it (below) but new way it the one I am trying now (above). They both work locally but not on GitHub Actions.

provisioner:
  name: ansible
  config_options:
    defaults:
      remote_user: molecule

Answer 1

The reason for the error is that the provisioner user (molecule) path was not the default path for the ansible role that I was using but a fallback path. In my test machine I do not have a XDG_CONFIG_HOME set, so it works. But GitHub Actions sets it to use runner user path to do the configs instead of the user I create for molecule images.

The way to bypass it is by forcing GitHub Actions to clean the value of XDG_CONFIG_HOME when running molecule, then everything works:

    - name: Run Molecule tests
      run: molecule test
      env:
        PY_COLORS: "1"
        ANSIBLE_FORCE_COLOR: "1"
        MOLECULE_DISTRO: ${{ matrix.distro }}
        XDG_CONFIG_HOME: ""