Primary client directory structure building fails when METADATA_FORMAT is changed to 'json' from 'der' tuf.conf.METADATA_FORMAT = 'json'

[mahmo136]

Problem Summary

Primary client directory structure building process fails when METADATA_FORMAT is changed to 'json' from 'der' in the uptane/init.py (tuf.conf.METADATA_FORMAT = 'json' )

Reading the documentation and source code, it seems like demo directory is expected to contain "pinned_primary_template.json" file, which does not exist.

When try to initialize the Primary client by using $ dp.clean_slate(), the following error message is displayed:

Unable to create Primary client directory structure. Does the Director Repo for the vehicle exist yet?

Expected Behavior

Both Primary and Secondary clients should be able to create the required directory structure.

Actual Behavior

Directory structure cannot be created on the Primary client.