How to create an external ldap role using the REST API?

It appears we don’t currently support creating external role mappings via the REST API (due to not including a source field) and at first glance I didn’t find an open ticket to add the functionality to the REST API. If you’d like this functionality added, please open a ticket on issues.sonatype.org against the “Dev - Nexus Repo (NEXUS)” project. That will help us track the requests for this functionality and may help get it prioritized.