Get current CPU load, memory usage and execution time.

excec-time-test is a small utility to retrieve the current system and measure it's own execution time. This is how you install and use it on an IoTmaxx gateway.

usage: python -m exec_time_test [-h] [-i <num>] [-s <s>]

get the current load of a linux system

options:
  -h, --help                    show this help message and exit
  -i <num>, --iterations <num>  # of iterations (default: 1)
  -s <s>, --sleep <s>           time(s) between iterations (default: 0.1)

Copyright (C) 2025 IoTmaxx GmbH

Run on IoTmaxx Gateway

Copy folder exec_time_test to /data/p1 on the gateway.

scp -r exec_time_test/ root@192.168.1.1:/data/p1

Interactive execution via ssh

ssh root@192.168.1.1 "cd /data/p1;python -m exec_time_test"

Non interactive execution via ssh

To remove the need for interactive authorization pre-shared keys can be used. To do so gateway and host have to be prepared as described in the following paragraph.

On the IoTmaxx gateway

Following steps have to be executed on the gateway.

Create ssh directory in /config partition.

mkdir -p /config/ssh/.ssh && chmod 700 /config/ssh/.ssh

touch /config/ssh/.ssh/authorized_keys && chmod 600 /config/ssh/.ssh/authorized_keys

Link ssh directory to /config partition

mount -o remount,rw /

ln -s /config/ssh/.ssh /root/.ssh

mount -o remount,ro /

Please be aware that currently firmware updates on the gateway will remove the symbolic link from /root/.ssh to /config/ssh/.ssh annd this step has to be repeated. Future firmware versions will contain this link and repeating this step will no longer be necessary.

On the host computer

This shows how the host computer is prepared.

Create dedicated ssh key pair for gateway access on host computer

mkdir -p ~/.ssh

ssh-keygen -t rsa -N "" -C "gateway access key" -f ~/.ssh/gw_rsa

Copy public key to gateway

cat ~/.ssh/gw_rsa.pub | ssh root@192.168.1.1 "cat >> ~/.ssh/authorized_keys"

Execute command

ssh -i ~/.ssh/gw_rsa root@192.168.1.1 "cd /data/p1;python -m exec_time_test"

Hint

In case you intent to connect to different gateways (with different host keys)from the same host you can add the following to ~/.ssh/config (create if not exists) to avoid ssh complaining about changed host keys:

Host 192.168.1.1
	StrictHostKeyChecking no
	UserKnownHostsFile /dev/null

Please be aware that this is considered insecure and would allow for man-in-the-middle attacks (you might be willing to accept this risk for gateways connected to your local LAN or directly to the host)