GRANT SELECT ON *.* TO zabbix@localhost IDENTIFIED BY 'mypassword';

На узел добавить макросы {$MYSQL.USER} и {$MYSQL.PASSWORD} и использовать рекомендуемые Template DB MySQL

/etc/sudoers.d/zabbix

zabbix ALL=(ALL) NOPASSWD:/usr/sbin/smartctl

chmod 440 /etc/sudoers.d/zabbix

/etc/zabbix/zabbix_agent2.d/feser-user-params.conf

UserParameter=cputemp,cat /sys/class/thermal/thermal_zone0/temp |awk '{print $1/1000}'
UserParameter=hddtemp,sudo /usr/sbin/smartctl -A /dev/sdb | grep Temperature_Celsius | awk '{print $10}'