Latest revision as of 21:39, 11 September 2022

[edit] Overview

reference: https://blog.victormendonca.com/2020/10/28/how-to-install-telegraf-on-freenas/
Setup and configure telegraf for TrueNAS (and probably any other FreeBSD OS)

[edit] Dependencies

[edit] Download and extract telegraf tar.gz

Find the latest telegraf release here
https://github.com/influxdata/telegraf/releases
Download and extract it on a vm with GNUtar (ubuntu, centos, etc) as tar included with FreeBSD will not unpack it.

[edit] Copy files over

You only need (2) files, the binary and conf file. Copy them over to TrueNAS.

~$ ./telegraf-[version]/usr/bin/telegraf
./telegraf-[version]/etc/telegraf/telegraf.conf

[edit] TrueNAS telegraf setup

[edit] Create dir and copy files

Create the directory your files will live in. I chose /usr/local/telegraf-[version]_freebsd_amd64 because /usr/local/ is the closest thing to /opt/ in freebsd

~$ sudo mkdir /usr/local/telegraf-[version]_freebsd_amd64
~$ cp /tmp/telegraf* /usr/local/telegraf-[version]_freebsd_amd64

[edit] Modify telegraf.conf

update the conf file to use prometheus instead of influxdb

~$ vim /tmp/telegraf-1.23.4_freebsd_amd64/etc/telegraf/telegraf.conf

comment

# [[outputs.influxdb]]

uncomment

[[outputs.prometheus_client]]
  listen = ":9100"
  path = "/metrics"

[edit] Create the init script

Modify the telegraf conf and bin dir vars.

~$ sudo vim /usr/local/telegraf-1.23.4_freebsd_amd64/telegraf.init
#!/bin/sh
# $FreeBSD$

# PROVIDE: telegraf
# REQUIRE: DAEMON NETWORKING
# BEFORE: LOGIN
# KEYWORD: shutdown

# Add the following lines to /etc/rc.conf to enable telegrafb:
# telegraf_enable="YES"
#
# telegraf_enable (bool): Set to YES to enable telegraf
# Default: NO
# telegraf_conf (str): telegraf configuration file
# Default: ${PREFIX}/etc/telegraf.conf
# telegraf_flags (str): Extra flags passed to telegraf

. /etc/rc.subr

name="telegraf"
rcvar=telegraf_enable

load_rc_config "${name}"
: ${telegraf_enable:="YES"}
: ${telegraf_flags:="-quiet"}
: ${telegraf_conf:="/usr/local/telegraf-1.23.4_freebsd_amd64/telegraf.conf"}
: ${telegraf_bindir:="/usr/local/telegraf-1.23.4_freebsd_amd64"}

pidfile="/var/run/${name}.pid"
command=/usr/sbin/daemon
command_args="-crP ${pidfile} ${telegraf_bindir}/${name} ${telegraf_flags} -config=${telegraf_conf}"

telegraf_prestart() {
# Have to empty rc_flags so they don't get passed to daemon(8)
  touch $pidfile
  rc_flags=""
}

telegraf_start() {
  ${command} ${command_args} ${rc_arg} >> /var/log/telegraf.log 2>&1
}

start_precmd="${name}_prestart"
start_cmd="${name}_start"

run_rc_command "$1"

[edit] Final steps

make the init executable

~$ chmod +x /usr/local/telegraf-1.23.4_freebsd_amd64/telegraf.init

create a symlink for telegraf.init

~$ ln -s /usr/local/telegraf-1.23.4_freebsd_amd64/telegraf.init /usr/local/etc/rc.d/telegraf

test the service

~$ service telegraf start

Add the following lines to /etc/rc.conf to enable telegrafb:

telegraf_enable="YES"

[edit] Create post init startup task

In the GUI go to:
Tasks > Init/Shutdown Scripts
and create a Command type with the following:

ln -s /usr/local/telegraf-1.23.4_freebsd_amd64/telegraf.init /usr/local/etc/rc.d/telegraf; service telegraf start

Select Post Init and Enable it.