I would like to perform some activities in a workflow only when a tag has triggered the build. I have tried filtering some steps within a workflow, and all steps within a workflow. When filtering some steps (but not all) in a workflow, those steps are not visualized in the workflow user interface, but they do run. When filtering all steps in the workflow, the workflow itself is completely absent from the workflows section in the user interface.
See https://github.com/pivotalservices/ignition/blob/v0.0.18/.circleci/config.yml#L111-L149 for an example of a configuration where all steps are filtered.