instruction: Create a Dockerfile for fundamentals
output: ```dockerfile
  from the test channel, run:
  
  $ curl -fsSL https://test.docker.com -o test-docker.sh
  $ sudo sh test-docker.sh
  Upgrade Docker after using the convenience scriptIf you installed Docker using the convenience script, you should upgrade Docker
  using your package manager directly. There's no advantage to re-running the
  convenience script. Re-running it can cause issues if it attempts to re-install
  repositories which already exist on the host machine.Uninstall Docker EngineUninstall the Docker Engine, CLI, containerd, and Docker Compose packages:
  
  $ sudo dnf remove docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin docker-ce-rootless-extras
  Images, containers, volumes, or custom configuration files on your host
  aren't automatically removed. To delete all images, containers, and volumes:
  
  $ sudo rm -rf /var/lib/docker
  $ sudo rm -rf /var/lib/containerd
  You have to delete any edited configuration files manually.Next stepsContinue to Post-installation steps for Linux.
  Request changesTable of contentsPrerequisitesOS requirementsUninstall old versionsInstallation methodsInstall using the rpm repositorySet up the repositoryInstall Docker EngineUpgrade Docker Engine<a class="link lg:no-underline" href=#install-
  ```