Re: [atomic-devel] ostree-docker-builder

[Clayton Coleman <ccoleman redhat com>]

Can we get this into Openshift as a new builder strategy / or source?
It's an excellent story for non-root builds.

> On Sep 30, 2015, at 9:01 PM, Giuseppe Scrivano <gscrivan redhat com> wrote:
>
> 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
>