Ubuntu without apt within less than 25 MiB.

• blitznote/baseimage

This is a demo which shows how using my patches to dgr you can create a minimal baseimage for APPC/ACI container runtimes, such as (but not limited to) CoreOS' rkt.

Any two builds will result in identical image files.

Please see blitznote/ubuntu for a complete README, including the advantages and system requirements for this container image. The most important difference is that this one does not ship with Perl and apt.

Example usage:

FROM blitznote/baseimage

RUN curl …

rkt image fetch blitznote.com/aci/base

You can find an extensive example, which uses this ACI as dependency and utilizes dgr for building, here.

1. Install rkt. Any version will do.
2. Download dgr, chmod a+x dgr, and copy it into your PATH.
   If you like you can build it yourself, first. Just run ./gomake
3. git clone … this repository. Then chdir into it, run sudo dgr build.

No matter how often or on what machine you run step (3), the resulting container image file will be the same. Reproducibly. sha256sum target/image.aci will show the same hash.

Given reproducibly built binaries, packaged in a way that retains that property, you can create with my fork of dgr reproducible container images. This is something which currently is not possible with Docker, the Docker Hub, or any tools for ACI/APPC container formats, except by manual tinkering.

The big picture regarding reproducible builds is to enable any observer to trust software binaries if he/she trusted its finite set of (ideally human-readable) source files. (Given the same applies for the tools used to achieve this.)