[Pulp-list] unit association attributes

[Dennis Gregorovic]

Hi,

I'm interested in exploring the option of having attributes that we can
set on unit associations.  For example, let's say that I have an ISO
which is mapped to two different repos.  I want to provide a description
of that ISO, but the description would be different in repo A than in
repo B.  

Currently, repo_content_units contains the following fields:
created
id
owner_id
owner_type
repo_id
unit_id
unit_type_id
updated

To keep things simple, a single 'notes' field could be added to this
table like the notes field that is available on repos.  

A more structured approach would be appealing, but could quickly get
complicated since the set of desired fields would vary by content type.

-- Dennis