ok thanks, I did see it there but assumed that was a temp file. I updated it according to the instructions, but I still get the same error.
# TYPE DATABASE USER ADDRESS METHOD
# "local" is for Unix domain socket connections only
local all all peer
host ovirt_engine_history ovirt_engine_history
0.0.0.0/0 md5
host ovirt_engine_history ovirt_engine_history ::0/0 md5
host ovirt_engine_history grafana 172.16.30.10 /0 md5
host ovirt_engine_history grafana ::0/0 md5
host engine engine ::0/0 md5
did a systemctl restart postgresql.service and I get "Unit not found". So I did systemctl restart ovirt-engine.service...
and the error I get when accessing from 172.16.30.10 is:
pq: no pg_hba.conf entry for host "172.16.30.10", user "grafana", database "ovirt_engine_history", SSL off