Adding Readme

.travis.yml

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 language: C
 
 # Travis-CI fails on Open vSwitch setup with 'Cannot find device "br-ex"'
+# TODO: Try "ovs-vsctl add-port br-ex eth2"
 script: make build

README.md

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+# DockStack – Docker on DevStack on Docker
+
+[![Build Status](https://travis-ci.org/janmattfeld/DockStack.svg?branch=master)](https://travis-ci.org/janmattfeld/DockStack)
+
+> This project installs DevStack inside a Docker container and integrates Zun, the current OpenStack container project.
+
+## Why
+
+A DevStack test installation should
+
+1. Not alter the host system
+2. Restart clean and fast
+3. Allow snapshots
+4. Be lightweight
+5. Run guest applications fast
+
+The most straight forward option `bare metal` lacks support for snapshots. It also alters the system heavily, rendering it unusable for other tasks. So it is only suitable for dedicated developer machines. Additionally, the well-known reset workflow of unstack/stack is unreliable, making this solution slow and annoying.
+
+So, get a virtual machine and all of the above problems would be gone! But performance would be nice. Instead of `VirtualBox`, we could use `libvirt` for nested-KVM. If you already know libvirsh, that may work fine.
+
+Running inside `LXD` containers might also be an option. They support multiple processes and feel more like a classic VM. Actually, they focus on IaaS [1]. However, an LXD-DevStack setup challenges just as much as on Docker [2].
+
+[1]: https://www.ubuntu.com/containers/lxd
+[2]: https://stgraber.org/2016/10/26/lxd-2-0-lxd-and-openstack-1112/
+
+### Not invented here
+
+Running Docker on DevStack actually has been done before [3]. However, we add the following:
+
+1. A maintained base image of Ubuntu 16.04 LTS
+2. Working systemd, as a base for
+3. OpenStack Ocata and Pike
+4. libvirt/QEMU support
+5. Zun instead of the deprecated Nova Docker
+6. A container-adjusted DevStack configuration
+
+[3]: https://github.com/ewindisch/dockenstack
+
+### Containers in OpenStack
+
+- Zun, OpenStack API for launching and managing containers backed by different technologies including Docker
+- Nova Docker (deprecated) [4], allows accessing containers via Nova's API, while Zun is not bounded by Nova's API
+- Nova LXD, pushed by Canonical to promote LXD, OpenStack itself may be installed within LXD with Juju
+- Magnum (Orchestration), a self-service solution to provision and manage a Kubernetes (or other COEs) cluster
+
+[4]: https://wiki.openstack.org/wiki/Docker
+
+## Start
+
+Clone this repository and make sure your host offers at least
+
+- Recent Linux (tested on Ubuntu 16.04 LTS and 17.04)
+- 4 GB of RAM available for the container
+- Docker (tested on 17.06.0-ce)
+
+The `Makefile` includes a complete Docker lifecycle. Image build and DevStack installation are simply started with
+
+```bash
+make
+```
+
+The first run can take up to 50 minutes, downloading all Ubuntu and Python packages. Subsequent container starts are much faster because of the Docker cache.
+
+Open Horizon at the displayed address or enter the running container directly with
+
+```bash
+make bash
+```
+
+Start a Cirros container via Zun
+
+```bash
+make test
+```
+
+More information can be found here [5].
+
+[5]: https://docs.openstack.org/zun/latest/dev/quickstart.html
+
+### Lifecycle
+
+Altough a container restart is faster than a complete build, it still takes up to 20 minutes. So for experimenting
+
+- save your running DevStack into the image via `docker commit`
+- use Docker checkpoints [6] (experimental)
+- if it works, use the classic `/devstack/unstack.sh` and `/devstack/stack.sh`
+
+[6]: https://criu.org/Docker