Extend controller with counters to measure activity
Add /a1-p/metrics endpoint to expose measures in Prometheus format
Document new environment variable prometheus_multiproc_dir
Issue-ID: RIC-353 Signed-off-by: Lott, Christopher (cl778h) <cl778h@att.com>
Change-Id: I44bc5346b627b27ba5b344187223dd0323b32a2c