Miscellanies about initializing an Ubuntu Server (II)

Error: Permission denied … when running Docker (perviously seen)

Better solution than before:

sudo groupadd docker
sudo usermod -aG docker $USER
sudo service docker restart

[UPDATE]
Looks like it is also required to logging out and back so that the group membership change takes effect (how?):

su -s ${USER}

And this is to check for group membership:

getent group groupname | awk -F: '{print $4}'

Potential issue when Docker for Ubuntu is installed and managed by Snap

Either systemd or systemctl won’t be able to locate or control Docker, which would occur when Docker is pre-installed with Ubuntu Server. Use snap commands instead:

sudo snap services docker
sudo snap restart docker

Local Build Preparation

This is likely to be a cure-all:

sudo apt install -y build-essential