onam@dev-1:~$ docker service ls
permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get...
sudo groupadd docker
onam@dev-1:~$ sudo usermod -aG docker $USER
[sudo] password for onam:
onam@dev-1:~$ ls -l /var/run/docker.sock
srw-rw---- 1 root root 0 Dec 18 13:18 /var/run/docker.sock
위와 같이 root root 로 그룹 권한이 root 로 나온다면 아래 명령어를 통해 수정 가능
sudo chown root:docker /var/run/docker.sock
onam@dev-1:~$ ls -l /var/run/docker.sock
srw-rw---- 1 root docker 0 Dec 18 13:18 /var/run/docker.sock
onam@dev-1:~$ docker service ls
ID NAME MODE REPLICAS IMAGE PORTS