Telegraf gathers metrics from your system and sends them to an InfluxDB server for storage. From InfluxDB you would typically use something like Grafana to plot the data.
Both Grafana and Influxdb are available through Community Apps

Configuration
Container Volumes:
/var/run/docker.sock Read Only. Location of your docker socket.
/var/run/utmp Read Only. Location of your utmp file.
/rootfs Read Only. To be mapped to the root of the host file system. This is so the disk usage reported will be that of the host system.
/rootfs/etc Read Only. To be mapped to the etc of the host file system. This is so the disk usage reported will be that of the host system.
/rootfs/proc Read Only. To be mapped to the proc of the host file system. This is so the disk usage reported will be that of the host system.
/rootfs/sys Read Only. To be mapped to the sys of the host file system. This is so the disk usage reported will be that of the host system.

Environment Variables:
INFLUXDB_RETENTION_POLICY Name of the retention policy. This should be present, but with no value assigned, as that is the default for InfluxDB 1.0.0 HOST_MOUNT_PREFIX Name of container volume mapping of the root file system.
HOST_ETC Name of the etc volume mapping of the root file system.
HOST_PROC Name of the proc volume mapping of the root file system.
HOST_SYS Name of the sys volume mapping of the root file sytem.
INFLUXDB_URL The url of the influxdb api, example: http://192.168.1.10:8086
CLICK ADVANCED VIEW AND SET THE ENVIRONMENT VARIABLES

More environtment variables are available and covered on the docker hub page: https://hub.docker.com/r/appcelerator/telegraf/.