This small Bash script will install the latest version of Docker on your Raspberry pi - It works on Raspberry Pi 4 B+ - Just run --> curl -fsSL http://bit.ly/2xm7kxb | sh

install-docker-rpi.sh

#!/bin/bash
##################################################
#-    version         ${SCRIPT_NAME} 0.0.1
#-    author          Marcos Soutullo
#-    license         GNU General Public License
# DESCRIPTION
# This small bash script will install Docker on your RaspberryPi for you without human interaction.
#    If your Raspbian version it's not currently available on get.docker.com
#    It will download use the latest Debian stable version defined in variable DOCKER_STABLE
# EXECUTION
# curl -fsSL http://bit.ly/2xm7kxb | sudo sh
# WARNING
# If you already have Docker installed, this script can cause trouble. 
#    If you installed the current Docker package using this script and are using it
#    again to update Docker, you can safely ignore this message.
##################################################

DOCKER_STABLE='18.09.7~3-0~debian-buster_armhf.deb'
CONTAINERD_STABLE='1.2.6-3_armhf.deb'
# Ensuring our system packages are up to date
apt update && apt upgrade -y

# Install packages to allow apt to use repository over HTTPs - Plus other useful stuff
apt install apt-transport-https ca-certificates software-properties-common git wget pparmor-utils avahi-daemon curl dbus jq network-manager socat

# Install Docker - 
curl -fsSL get.docker.com -o get-docker.sh && sh get-docker.sh || {
echo "It seems that your distribution is not available yet We're going to install compiled images on docker-${DOCKER_STABLE} \
and containerd-${CONTAINERD_STABLE}"
wget https://download.docker.com/linux/debian/dists/buster/pool/stable/armhf/containerd.io_$CONTAINERD_STABLE
wget https://download.docker.com/linux/debian/dists/buster/pool/stable/armhf/docker-ce-cli_$DOCKER_STABLE
wget https://download.docker.com/linux/debian/dists/buster/pool/stable/armhf/docker-ce_$DOCKER_STABLE

dpkg -i containerd.io_$CONTAINERD_STABLE
dpkg -i docker-ce-cli_$DOCKER_STABLE
dpkg -i docker-ce_$DOCKER_STABLE }

usermod -aG docker ${USER} && su - ${USER}