After installing the docker, each time you enter a command docker be prefixed with sudo, very annoying, we join docker current user groups do not need to have to keep entering the sudo
See if there docker group
sudo cat /etc/group | grep docker
View the current user input that group
groups
View a user belongs to which group
groups ${user name}
The user group is added docker, $ {USER}, it means that the user name
sudo gpasswd -a ${USER} docker
Restart docker Service
sudo service docker restart
or
sudo systemctl restart docker
Switching the current session to a new group or restart X session
newgrp docker
or
pkill X
Or use the exit to exit the current session command to log in again
Note: The last step is necessary, the group just added information not entered into force because the session is still using the old cache inside information, so docker images execution was also unable to get rid of sudo.
Reference connection
View user group, join user groups
https://www.cnblogs.com/pengyunjing/p/8543026.html