:whale: Docker on DevStack on Docker ¯\_(ツ)_/¯
This project installs DevStack inside a Docker container and integrates Zun, the current OpenStack container project.
A DevStack setup should
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! Except for performance of course. Instead of VirtualBox, we could use libvirt with nested-KVM and speed things up. 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], [9].
Also note OpenStack Kolla, which builds individual Docker containers for every project [10].
Running Docker on DevStack actually has been done before [3]. We add the following:
Zun [5], 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
And some more. Get an overview [13].
The Makefile includes a complete Docker lifecycle. Image build and DevStack installation are simply started with
$ git clone https://github.com/janmattfeld/DockStack.git$ cd DockStack$ makeThis is your host IP address: 172.17.0.2Horizon is now available at http://172.17.0.2/dashboardKeystone is serving at http://172.17.0.2/identity/The default users are: admin and demoThe password: secretServices are running under systemd unit files.DevStack Version: pikeOS Version: Ubuntu 16.04 xenial
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.
make bash.make test.Internet access for OpenStack instances
public-subnet and enable DHCP with a custom DNS server i. e. 8.8.8.8.Reaching an OpenStack instance from your host through Docker
Ping: Ingress, IPv4, ICMP, Any, 0.0.0.0/0
$ ip route172.24.4.0/24 dev br-ex proto kernel scope link src 172.24.4.1$ sudo ip route del 172.24.4.0/24$ sudo ip route add 172.24.4.0/24 via 172.17.0.2$ ip route172.24.4.0/24 via 172.17.0.2 dev docker0
Pulling a new Docker image might fail with 'module' object has no attribute 'get_config_header' because of an old docker-py version [[11]] [12].
# Remove any Docker SDK artifactspip uninstall docker docker-pyrm -rf /usr/local/lib/python2.7/site-packages/docker/auth/# Get the current version, now just called `docker`pip install docker# Make Zun aware of the new Docker librarysudo systemctl restart devstack@zun*
Feel free to adjust the file local.conf for your needs [8].
Although a container restart is faster than a complete build, it still takes a few minutes. So for experimenting use
docker commit to save your running DevStack into the image/devstack/unstack.sh and /devstack/stack.shIf you really messed it up, make clean followed by make run will set up a fresh DevStack.