Comment 6 for bug 1931558

I looked into this as my hat of horizon-core.

A content uploaded as "definition_upload" is accessed at [1]. read() method just retrieves the uploaded content, so the return value would be "/etc/password" in the test upload here. It will be passed to mistraldashboard.api.workbook_validate [2] and api.workbook_validate calls workbooks.validate() from mistralclient [3]. Looking at the response in the bug description, the call [3] fails and an error message was provided to a caller.
This looks like a bug in mistral (or mistralclient) rather than mistral-dashboard.

This is my observation from POV of dashboard implementation. Apparently horizon is not involved in it, so I am marking horizon status as Invalid.

Further action is up to the mistral team.

[1] https://opendev.org/openstack/mistral-dashboard/src/commit/fa785b2bb8314d0981d343bd51fe645017a38cca/mistraldashboard/workbooks/forms.py#L67
[2] https://opendev.org/openstack/mistral-dashboard/src/commit/fa785b2bb8314d0981d343bd51fe645017a38cca/mistraldashboard/workbooks/forms.py#L74-L76
[3] https://opendev.org/openstack/mistral-dashboard/src/commit/fa785b2bb8314d0981d343bd51fe645017a38cca/mistraldashboard/api.py#L262-L268