Hello, I was experimenting for fun with creating Docker images using rpm-ostree instead of "docker build". rpm-ostree already supports it, and it can be specified in the .json file setting the "container" flag to true. The generated tree can be tarred and imported directly into Docker.
I wrote a small program to simplify the generation of the image, available on github: https://github.com/giuseppe/ostree-docker-builder The commands below, for example, will be enough to generate an Emacs container: $ cat emacs.json { "ref": "fedora-atomic/f22/x86_64/emacs", "repos": ["fedora-22"], "container": true, "packages": ["emacs"] } $ sudo rpm-ostree --repo=repo compose tree emacs.json $ sudo ostree-docker-builder --repo=repo -c emacs fedora-atomic/f22/x86_64/emacs --entrypoint=/usr/bin/emacs-24.5 ostree-docker-builder also supports pushing the image to the registry if something has changed (thanks to Colin for suggesting this!), it uses a Docker LABEL to remember the OStree commit used to generate to image. The two advantages of using it are: - The same tool to generate the OS image and the containers. - Use OStree to track what files were changed, added or removed. If there are no differences then no image is created. Any comments? Thanks, Giuseppe
