I started playing with Docker in 2016. I am still amazed by its power and simplicity. Being confined at home and kind of bored on this rainy day I resumed hacking a Raspberry Pi with Docker, connected to IPad and now plugging a ScrollPhat I found to monitor cpu, temp and number of docker images running.
Install Docker
From your SSH session type in curl -sSL https://get.docker.com | sudo -E sh, this will setup Docker on your Pi.
Now let the Pi user have access to the Docker daemon and reboot by typing in:
$ sudo usermod -aG docker pi
$ sudo reboot
To check everything worked you can list the running containers (which should come back empty)
$ docker ps
I found a ScrollPhat from Pimoroni in one of my cupboard and I decided to use it to monitor the Raspberry Pi.
The idea is to write a Python program to display temperature, CPU load and number of containers running on Docker.
It will also be the occasion to explore a bit more Python and especially parameters management.
The final program is available on GitHub github.com/fxmartin/ScrollPhatDockerPi
All the examples I found were clearing/updating the full matrix of LEDs resulting in a kind of blinking effect. I looked for a smarter way to shut on/off the LEDs in order to avoid the blinking effect.
Below a short video to demonstrate how it works. I took this video while compiling CV2 library so it explains why the CPU load is high. It was a good way to test the program and the PI.
Initially I included the monitoring of docker containers but when trying to run the Python program as a service then I faced an error message with import docker so after 2h of investigations I decided to remove it.