Can't add user to docker group
I'm trying to set docker up on a new system, and when running docker info I get:
docker -v
=> Docker version 18.09.5, build e8ff056
docker info
=> Got permission denied while trying to connect to the Docker daemon
socket at unix:///var/run/docker.sock: Get
http://%2Fvar%2Frun%2Fdocker.sock/v1.39/info: dial unix
/var/run/docker.sock: connect: permission denied
Following the docs, I've tried:
sudo usermod -a -G docker $USER
Which returns no output. When I then run groups:
groups
=> mark adm cdrom sudo dip plugdev lpadmin sambashare
I can see a docker group exists:
less /etc/group | grep docker
=> docker:x:131:mark
And can see that it owns a socket running where the error message states:
ls -la /var/run/ | grep docker
=>
drwx------ 5 root root 120 May 25 14:54 docker
-rw-r--r-- 1 root root 5 May 25 14:54 docker.pid
srw-rw---- 1 root docker 0 May 25 14:54 docker.sock
So why can't I add myself to that group with sudo usermod -a -G docker $USER ?
Answer
You need to reload your shell in order to make the changes take effect. Often you need to reboot your shell process and possibly even restart your computer.
e.g
sudo usermod -aG docker $USER
sudo reboot
See @4Z4T4R answer and give a thumbs https://stackoverflow.com/a/66297855/7961500
Load changes without quitting your shell
To avoid starting a new shell you can run. (Doesn't seem to work for all environments)
exec su -l $USER
This will create a new subshell with the loaded changes and replace your current shell with it.
If nothing else is working for you.
Another way if you just need to get it working now, is to change your primary group. This is only a temp solution as with any new shell you will need to apply it again.
export my_group=$(id -gn)
newgrp docker
newgrp $my_group
Documentation
You can also look at the offical documentation here https://docs.docker.com/engine/install/linux-postinstall/