Zero Downtime Deployments with Docker

This talk basically talks about how we can use haproxy and docker instances to avoid downtime during Rails deployments.

Transcript

1. Zero Downtime Deployments with Docker Vamsee Kanakala @vamsee
2. What is Docker? • Commoditizes LXC • Portable deployments across machines • Efficient, quick provisioning • Near-native performance • Git-like versioning of images • Component re-use • Application-centric
3. What is LXC? • Provides OS-level virtualization for Linux • Own process space • Own network interface • Own init framework • Isolation achieved with cgroups • But shares kernel with the host
4. A typical Docker Image
5. Basic workflow • Pull docker images from public registry • Run it on your host • Add your own changes • Push it back to share them • Or you could build from ground up... • You can setup a private registry • Or you can sign up for a SaaS offering
6. Dockerfile • The default way to build it from base image • Basically a glorified shell script • But definitely easier to maintain • FROM, RUN, CMD, EXPOSE, ENV, ADD, VOLUME, ENTRYPOINT, etc. • You can create your own base image with tools like debootstrap
7. Zero-Downtime Deployments • Why do you need them? • Continuous delivery • Continous deployments • Rails – long deploys • Migrations? Funny things happen • Asset compilation... zzz • Not limited to Rails, though
8. Server layout
9. Outline of our approach
10. Dockerfiles and demo... • App server Dockerfile • The deployment code.. • Let's see it in action.
11. Some helpful links... • http://ww.docker.io • http://haproxy.1wt.eu/ • http://www.dockerbook.com/ • http://tech.yandex.ru/events/yac/2013/talks/108 5/ • Dokku, Flynn.io, CoreOS, Deis.io, Quay.io, Orchardup.com, and many more...
12. Thank you! Questions?