Not easy to view current job using a Resource Group

Proposal

Allow for the Resource Group's current job to be accessible via REST API, similar to how a Resource Group's upcoming jobs are accessible via upcoming_jobs.

Problem

Sometimes it's difficult to identify quickly which job is utilising the Resource Group and causing "locks" to that Resource Group.

Current options to see this information:

• Exposed in the UI for specific jobs that are waiting for resources
• Rails console