How to fix docker: Got permission denied issue

Question

I installed Docker in my machine where I have Ubuntu OS. After than I installed docker, when I run

sudo docker run hello-world

All it\'s ok

Answer 1

lightdm and kwallet ship with a bug that seems to not pass the supplementary groups at login. To solve this, I also, beside sudo usermod -aG docker $USER, had to comment out

auth optional pam_kwallet.so
auth optional pam_kwallet5.so

to

#auth optional pam_kwallet.so
#auth optional pam_kwallet5.so

in /etc/pam.d/lightdm before rebooting, for the docker-group to actually have effect.

bug: https://bugs.launchpad.net/lightdm/+bug/1781418 and here: https://bugzilla.redhat.com/show_bug.cgi?id=1581495