The Docker script doesn't do the useradd apparently?

[ChrisSimmons]

Even after running the script, I see the following when running any meaningful docker command (e.g. docker ps):

docker: permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Head "http://%2Fvar%2Frun%2Fdocker.sock/_ping": dial unix /var/run/docker.sock: connect: permission denied.

This bit should have covered it:

sudo groupadd docker
sudo usermod -aG docker $USER

It doesn't seem to be sudo groupadd docker as when I run that I get groupadd: group 'docker' already exists. When I run sudo usermod -aG docker $USER and then logout/login, I can then run docker ps without error.