Docker¶

Check Docker is Running¶

sudo systemctl status docker

sudo systemctl start docker
sudo systemctl enable docker

If you get permission errors when running Docker commands, ensure your user is in the docker group.

sudo usermod -aG docker $USER

Log out and back in for the group change to take effect.

If container image pulls fail, check network connectivity and Docker Hub access.

docker pull hello-world

If behind a proxy, configure Docker's proxy settings in /etc/docker/daemon.json or via systemd drop-in.

Check container logs for errors.

docker logs <container_name>

To reclaim disk space from unused containers, images, and volumes:

docker system prune -a

Warning

This removes all stopped containers, unused networks, dangling images, and build cache.