Run uname -a to check the version of the currently running Linux kernel:
uname -a
Check that it's a 64Bit Kernel (x86_64). Docker won't work without this.
Check the Ubuntu version.
cat /etc/lsb-release
The command shows that the Ubuntu version is 16.04.
It is recommended to update Ubuntu before you install new software. Run the following command to fetch the latest updates from the Ubuntu repository and install them.
sudo apt update sudo upgrade
Now install docker with the apt command:
sudo apt install -y docker.io
Wait until the installation has been completed.
sudo usermod -aG docker $USER
NOTE: This allows docker to be run without using sudo.
To enable this functionality, log out and log back in; or run:
newgrp docker
docker run hello-world
NOTE: If an error is seen such as docker: Got permission denied while trying to connect to the Docker daemon socket, then:
sudo chmod 666 /var/run/docker.sock
systemctl start docker
systemctl enable docker
docker version
Show the currently installed Docker version.
NOTE: docker is now installed.