A Gluecon 2017 talk on why section.io uses Kubernetes to build a content delivery network that properly supports agile and devops teams. Demo code is available on github

1. Kubernetes in the Wild
Building a
Content Delivery Network
on Kubernetes
Daniel Bartholomew, CTO, section.io

2. What to expect from this talk
Drastic oversimplifications
Opinionated statements
Errors and omissions
Tempting fate - Live code!

3. What are we going to cover?
Some background on CDN design
Some Kubernetes concepts
Live Demo using Nginx, Varnish and
(maybe) OpenResty

4. What makes up a CDN??
1. Physical Layer: computers, network,
global locations
2. Logical Layer: HTTP reverse proxies

5. Why would Kubernetes fit this model?
Kubernetes provides an elegant
framework for running lots of
workloads.
For CDN, the logical layer.

6. Just f’ing hardcode it!!?
Most CDNs hardcode specific proxies
into their network
We think that this reduces architectural
options, leading to suboptimal systems

7. Focus has shifted
CDNs used to provide a big boost just
on the physical layer
Now CDNs operate more in the logical
layer

8. Why is that important?
Moving to the logical layer started to
have effects on the application
But the CDN isn’t part of the
development environment

10. Desired state
Provide a CDN that supports:
Architecture - freedom of choice
Agile - in dev, CI, CD
Devops - dev works like prod

11. Architectural options
Don't hardcode the proxies
Provide a library to developers. Choose
from caching, security, optimization.
Mix and match to suit.

12. Agile
Provide a source controlled workflow
to move code and configuration from
development through to production.
Assert outcomes along the way.

13. The devops thing
Provide consistency in process
Move CDN from “ops only” to dev
Debug production like you do in dev

14. Why Kubernetes?
Kubernetes provides all the basic
components to serve HTTP traffic
HTTP Ingress
Run HTTP servers inside containers
Control linking containers together in the cluster

15. Inside the CDN logic layer

16. Kubernetes helps the dev workflow
Minikube to run on your computer
Source controllable
Production grade clusters

17. Let's build some stuff
1. Get Minikube to proxy traffic for
gluecon.com
2. Add Varnish to cache it
3. Add Openresty to alter it

18. Step 1: get minikube to proxy some stuff

19. Step 2: Add Varnish Cache

20. Step 3: Add OpenResty

21. Takeaways
CDN should not be production only
Kubernetes is awesome
Most enterprise systems can leverage
its awesomeness

22. Thank you!
www.section.io
@sectionio
@dbartholomew