This document discusses Docker and its integration with OpenStack. It provides five major use cases for Docker: alternative virtualization, continuous integration/delivery, scaling applications, cross-cloud deployment, and resource/security isolation. It also describes a demo of pushing a containerized application through development testing and multiple clouds without downtime. Additionally, it outlines the Docker plugin for Nova in OpenStack which enables control of Docker containers via the Nova API and Horizon UI.

1. Docker &
March 27th, 2014

2. What?
Compute

3. Why Docker?!
(an incomplete list)
• Compatibility with Docker
images (if standardizing or
desiring cross-cloud compat.)
• Dockerfiles provide flexible,
repeatable image building
• Global, multi-cloud image
registry
• Layered images / builds
• Completeness of vision

4. Five major use cases
• Alternative form of virtualization for multi-tenant services!
• Continuous Integration/Continuous Delivery:!
• Go from developer’s laptop, through automated test, to production, and through
scaling without modification!
• Scale-out/Big Data:!
• Rapidly scale same application across hundreds or thousands of servers…and scale
down as rapidly!
• Cross Cloud Deployment!
• Move the same application across multiple clouds (public, private, or hybrid) without
modification or noticeable delay!
• Resource and Security Isolation:!
• Docker simplifies the separation of security concerns. Multiple processes of the same
“application” may run on a host, linked together, sharing resources but within separate
security contexts (SeLinux labels, Linux capabilities, Cgroups, etc)

5. Demo at OpenStack Summit HK
• Application Containerized from Source!
• Application Goes Through Development Testing!
• Push from laptop to Rackspace Cloud!
• No downtime or modification required!
• Push from Rackspace to Digital Ocean!
• No downtime or modification required!
• Push from Digital Ocean to OpenStack Cluster!
• No downtime or modification require!
• Provision via Horizon – Native Havana Nova Integration
http://bit.ly/
KQyIZC
Watch: Write Once and REALLY Run
Anywhere with OpenStack and Docker

6. Closer to the Docker workflow
Hybrid-cloud compatible
Scheduled by backing cloud
Integration with other services
Nova features (quota, auth, etc…)
Abstraction layer for other hypervisors
Integrated scheduling
Heat vs Nova!
Comparison

7. Project
SOLUM
“Convert code into a managed application running
on an OpenStack cloud at the push of a button.”
FROM CODE TO MANAGED APP

8. Docker Docker
Key element of the Solum data plane

9. Compute Integration
Docker plugin for Nova

10. What?
Enables control of
Docker via OpenStack:
• Nova API
• Horizon UI
Supports:
• launch
• terminate
• reboot
• serial console
• snapshot
• glance
https://wiki.openstack.org/wiki/
HypervisorSupportMatrix

11. Not supported.!
(yet)
Neutron
Cinder Volumes
Suspend/resume
Pause/unpause
(patches welcome!)

12. Image Management
docker-registry is a proxy
!
users can upload through docker-
registry or to glance directly
!
docker pulls images through the
docker-registry proxy

13. Nova+Docker!
Architecture Overview

14. Testing

15. Applying Heat
Orchestration for Docker API

16. Heat Resource

17. Heat Workflow
Heat API
VM
Docker
NovaNova resource
Docker resource
Container1
Container2
Container3
HOT

18. Heat Template
heat_template_version: 2013-05-23
description: Single compute instance running cirros in a Docker
container.
resources:
my_instance:
type: OS::Nova::Server
properties:
key_name: ewindisch_key
image: ubuntu-precise
flavor: m1.large
user_data: #include https://get.docker.io
my_docker_container:
type: OS::Heat::Docker
docker_endpoint: { get_attr: [my_instance, first_address] }
image: cirros

19. dockenstackan alternative to vagrant/vms for devstack

20. ! nested

21. Where container == host; for all practical purposes
Host
VM
Linux
VM
Host
Container
Linux
VM
Vagrant
(or other VM devstack environment)
Dockenstack

22. Pre-cached resources
• Pre-installed all ‘pip’ requirements
• Checkout of all git repositories
• All required ubuntu packages installed, or downloaded
(in the case of non-prime packages)
• Each are ‘freshened’ on boot with updates so the pre-
caching has no negative effect.
The image arrives prepared…

23. Negatives of dockenstack…
• No RHEL / SuSe / Fedora support (yet)
• Only tested with LXC and Docker virt drivers,
but shouldn’t have problems with other drivers.

24. Q & A