Another weekend, another project of my son. For whatever reason he has suddenly become very privacy focused and asked me to sell his Alexa and run a pihole on one of our Raspberry Pi’s. Now - given that I had to reinstall the RPi multiple times after some of his other crafty experiments - this felt like a good time to use his enthusiasm and have him learn docker.

But as usual (sadly I must admit), trying to find a simple step-by-step tutorial turned into a chase of breadcrumbs across the web. So for your and my benefit, here is a summary of my steps to get docker and docker-compose up and running on a RPi. After I had finished my setup I stumbled across Installing Docker and Docker Compose on the Raspberry Pi in 5 Simple Steps which further reduces the steps needed. Your leverage might vary, but from briefly reviewing it, it might do the trick as well.

The following steps are based on Happy Pi Day with Docker and Raspberry Pi with the missing command for apt-key taken from Docker Tutorial 1: Docker Installation in Ubuntu 18.04 and How to fix docker: Got permission denied while trying to connect to the Docker daemon socket to allow the pi user to run docker.

Execute the following steps to install docker (details for each step see here):

• sudo apt-get install apt-transport-https ca-certificates software-properties-common -y
• curl -fsSL get.docker.com -o get-docker.sh && sh get-docker.sh
• sudo usermod -aG docker pi
• sudo curl https://download.docker.com/linux/raspbian/gpg | sudo apt-key add -
• sudo add-apt-repository "deb https://download.docker.com/linux/raspbian/ stretch stable"
• sudo apt-get update
• sudo apt-get upgrade
• systemctl start docker.service
• docker info

If after the last step you get the following permission problem

> Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.40/containers/json: dial unix /var/run/docker.sock: connect: permission denied

Apply the following fix (from here):

• sudo chmod 666 /var/run/docker.sock

But installing docker is only half the fun without docker-compose (taken from here):

• sudo apt-get install libffi-dev libssl-dev
• sudo apt-get install -y python python-pip
• sudo apt-get remove python-configparser
• sudo pip install docker-compose

To see if it all works, run yourself a portainer instance on your RPi (inspired by this). Create a docker-compose.yml file with the following content

dockerui:
  image: portainer/portainer:arm
  restart: always
  volumes:
    - '/var/run/docker.sock:/var/run/docker.sock'
  expose:
    - 9000
  ports:
    - 8080:9000

and run it in the same directory with docker-compose up.

To find the corresponding docker-compose definition for pihole, visit their github repo at https://github.com/pi-hole/docker-pi-hole/.

Docker you should, if not want in installation hell you live.