Summary

The default client version is currently Dockerv19 which is missing a feature that was in previous and newer versions.

Specifically, in versions prior to v19, you were able to omit a tag and the result was to push all tags, in v19 this default was changed to only push latest without providing an option/feature flag to then push to all. In v20, this feature flag now exists.

Workaround

You can upgrade the client version of docker yourself by either using an appropriate image or by downloading and installing the newer version as a build step.

Example image with dockerv20 client

pipelines:
  default:
    - step:
        image: atlassian/pipelines-docker-daemon:v20-stable
        services:
        - docker
        script:
        - docker version

Example install of dockerv20 into any existing image (also works on default image)

pipelines:
  default:
    - step:
        services:
          - docker
        script:
          - curl -s -O https://download.docker.com/linux/static/stable/x86_64/docker-20.10.5.tgz
          - tar --extract --file=docker-20.10.5.tgz
          - ls -al ./docker
          - export PATH=./docker:$PATH
          - which docker
          - docker version