Some advanced things that you might want to do within a container, such as Docker-in-Docker (DinD), NTP, mounting loopback devices, and many others, will require higher privileges than the ones given to the root user of the container by default. As such, additional privileges need to be allowed for the container to run without issues, so for that use case, Docker has a very simple but extremely broad privileged mode that adds the complete host's capabilities to the container. To use this mode, just append --privileged to the docker run command:
Docker-in-Docker (commonly known as DinD) is a special configuration of a container that allows you to run the Docker Engine within the container that ...
