Permission denied while trying to connect to the Docker daemon socket

Question

On Ubuntu 16.04 LTS whenever trying using docker login command the following warring message will be show :

docker login
Warning: failed to get default registry endpoint from daemon (Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.30/info: dial unix /var/run/docker.sock: connect: permission denied). Using system default: https://index.docker.io/v1/
Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com to create one.
Username: csomethingr
Password: 
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.sock/v1.30/auth: dial unix /var/run/docker.sock: connect: permission denied

Any solution?

Answer 1

use sudo docker login

or as @Serey mentioned add your user to docker group

usermod -aG docker $USER

and disconect from your session!

Answer 2

you have to add the user to the docker group as the other posts suggest

usermod -aG docker $USER

This change won't affect your current terminal session however. If you don't want to login/logout you can use

newgrp - docker

for the change to affect to your current terminal session.