ubuntu@ip-10-0-0-12:/var/run$ cat /etc/group | grep docker
docker:x:117:ubuntu
ubuntu@ip-10-0-0-12:/var/run$ ls -l docker.sock
srw-rw---- 1 root docker 0 Jan 29 22:11 docker.sock
ubuntu@ip-10-0-0-12:/var/run$ cat docker.sock
cat: docker.sock: Permission denied
ubuntu@ip-10-0-0-12:/var/run$