monitoring: persist Grafana DB with -G option

[tarzanek]

same as we do for alert manager and of course prometheus,
we should persist grafana settings (it likely shouldn't persist dashboards, which needs to be tested, dashboards should come from distro/version)

https://github.com/scylladb/scylla-monitoring/blob/master/start-all.sh#L75
-G path/to/Grafana/data-dir - Set an external data directory for the Grafana data.

should do the trick

the goal is to persist any custom rules people will write in Grafana UI

[tarzanek]

@vladzcloudius this is needed for persisting of more users or grafana settings

I did only quick test and containers failed to load when I used -G , permission options, so let's test this properly (it is possible there are bugs upstream here)

[vladzcloudius]

@vladzcloudius this is needed for persisting of more users or grafana settings

I did only quick test and containers failed to load when I used -G , permission options, so let's test this properly (it is possible there are bugs upstream here)

@tarzanek Please, paste the error that you've got when you tried -G option.
Did you validate that the directory that you used indeed had required permissions?
Please, provide the ls -al for that directory as well.