Error: Must provide --username with --password-stdin

[mristin]

Hi,
I tried to build a multi-arch image in a workflow based on this article: https://github.com/docker/build-push-action#multi-platform-image

However, when I run it, I get the error:

Error: Must provide --username with --password-stdin

Please see the full build log here: https://github.com/admin-shell-io/aasx-server/pull/41/checks?check_run_id=1264107244

[mristin]

I figured out the issue. The problem is that I didn't set up the username correctly. In my workflow I wrote:

      - name: Login to DockerHub
        uses: docker/login-action@v1
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_PASSWORD }}

whereas the secret was DOCKERHUB_USER, so the username was empty. However, the message is really misleading in this case:

Error: Must provide --username with --password-stdin

You probably need to do a more refined check here: https://github.com/docker/login-action/blob/master/src/docker.ts#L23:

  if (username) {
    loginArgs.push('--username', username);
  }

?

Is the standard loging without the username possible at all? Shouldn't an empty username already be a red flag and raise an exception?

[crazy-max]

@mristin Indeed the username should be required. I will push a fix, thanks for your input.