====== erster Docker Container ======
erste Docker Instanz starten:
  docker run hello-world
oder (( A string that is used to identify an image is called an image reference. An image reference has these parts: ''[host[:port]/][namespace/]repository[:tag][@digest]'' https://docs.docker.com/reference/cli/docker/image/tag/ ))
  docker container run docker.io/library/hello-world:latest

Image anzeigen:
  docker image list
-> ''REPOSITORY    TAG       IMAGE ID       CREATED       SIZE''

-> ''hello-world   latest    e2ac70e7319a   8 weeks ago   10.1kB''
++++ podman |
-> ''quay.io/podman/hello           latest      5dd467fce50b  24 months ago  787 kB''
++++
  docker image inspect hello-world
++++ podman |
  podman image inspect docker.io/library/hello-world
++++
====== Ubuntu Container =====
"offiziellen" Ubuntu Container suchen:
  docker search --filter=is-official=true ubuntu
-> weitere Images siehe https://hub.docker.com

Ubuntu im Terminal starten:
  docker container run -it ubuntu bash

====== erste Befehle in Docker ausführen ======

''sort'' mit Ubuntu im Container:
  docker container run -i --rm ubuntu sort < /etc/passwd

''sort'' mit Alpine im Container:
  docker container run -i --rm alpine sort < /etc/passwd