You can’t run docker directly inside a docker container.
But you can use the docker-cli to call the docker installed on your own machine.
Your docker container can start other container or manage it by passing as a volume the docker.sock
docker run -it -v /var/run/docker.sock:/var/run/docker.sock docker docker run -it --rm hello-world
here, you use the docker cli to start a contianer using the docker image, but you can use your custom one.
the -v allow you to pass files or directory of you own machine inside the container, here I use the docker socket because it allow the container to communicate to my host docker.
Just after the volume, I have “docker” this is the image name. You can use Ubuntu but you need to install docker-cli on it.
After the image name, I have my command. this dommand will run a docker image using the hello-world image.