Version:

$ openshift-install version
OpenShift 4.6 

Platform:
ovirt 

Please specify:
* UPI (semi-manual installation on customized infrastructure)

What happened?

When you use the UPI Ansible playbooks, it relies on the environment variable ASSETS_DIR to be defined and pointing to something real. This is clearly documented.  However, if there use forgets to define this environment variable, when they run the playbook they get the very cryptic and unhelpful error message:

>  [WARNING] provided hosts list is empty, only localhosts is available.  Not that the implicit localhost does not match 'all'
> 
> PLAY [localhost] *****
> 
> TASK [including metadata.json cards] ****
> fatal: [localhost]: FAILED! => {"ansible_facts": {"metadata": {}}, "ansible_included_var_files": [], "changed": false, "message": Could not find or access '/metadata.json' on the Ansible controller.\nIf you are using a module and expect the file to exist on the remote, see the remote_src option"}

What did you expect to happen?

Give the user guidance how to fix the problem. If ASSET_DIR is required to be defined, we can check it before the run, or give a clearer message after the failure.

How to reproduce it (as minimally and precisely as possible)?

Run UPI install without ASSET_DIR defined.

Anything else we need to know?

This failure came up during a recent OpenShift Twitch live stream.