InfluxDB confugration, use hostname as prefix

[Kye]

Here is the configuration I tried to use, but $HOSTNAME isnt a valid prefix, or is interpreted literal in Grafana.  Is the a valid prefix to give me the actual hostname that is running the client instead of manually having to enter the value.

[influxdb]
	# Configuration for the --export-influxdb option
	# https://influxdb.com/
	host=<IP>
	port=8086
	user=<UID>
	password=<PW>
	db=<DB>
	prefix=$HOSTNAME
	#tags=foo:bar,spam:eggs

[Kye]

Just used sed and replaced it instead with the hostname from cmd.  

sed -i "s/hostname/$(hostname)/g" glances.conf

[Nicolargo]

I also add an enhancement request to allow user to use whatever variable in conf file: https://github.com/nicolargo/glances/issues/1204

[Nicolargo]

Available in the DEVELOP branch of the future Glances 3.0 release.

Can you test it ?

See https://github.com/nicolargo/glances/issues/1204