Jan Kunigk and Paul Wilkinson show how to secure Solr collections:
The policy shown below establishes four Sentry roles based on the
admin,operators,users, andtechusersgroups.
Administrators are entitled to all actions.
Operators are granted update and query privileges.
Users are granted query privileges.
Tech users are granted update privileges.
These are pretty straightforward role-based access controls. The authors also look at accessing the data via Flume and a couple other technologies.