This reduces the system metric collection time by using a wait group
and go routines to allow the systemd metric calls happen concurrently.
Also, makes the start time, restarts, tasks_max, and tasks_current metrics disabled by default
because these can be time consuming to gather.
Signed-off-by: Paul Gier <pgier@redhat.com>
* Change systemd unit filtering
Get all units from systemd and filter in Go.
* Improves compatibility with older versions of systemd.
* Improve debugging by printing when units pass the filter.
* Remove extraneous newlines from log messages.
Signed-off-by: Ben Kochie <superq@gmail.com>
