To run docker commands, you either need to be a root user or run the commands with sudo.
To run docker commands with a regular user, you need to add that user to the docker group.
The docker group manages access to the dockerd Unix socket.

By default, the docker group is created.
$ grep docker /etc/group docker:x:999:

• Add your user to the docker group:
  $ sudo usermod -aG docker mtitek
  
• You need to log out and log in to your account to activate the changes to groups.
  You can optionally use the command newgrp to activate the changes to groups during your login session:
  $ newgrp docker
  
• You can now run docker commands without using sudo.
  Verify that you can execute docker commands with your user:
  $ docker run hello-world Hello from Docker! This message shows that your installation appears to be working correctly.