Short intro to what is Kubernetes and why it is important. NOT a tutorial - this is the business/technical justification. [updated version 4/11]

1. Kubernetes in 15 minutes
Rob “@zehicle” Hirschfeld
CEO/Founder, RackN
http://robhirschfeld.com
RackN leads in physical IT ops automation
We deploy multiple container workloads
Including Kubernetes, Docker Swarm, Mesophere,
StackEngine and CloudFoundry

2. First, a Kubernetes Analogy
If building an application
with containers is like
making a house of cards
Then Kubernetes is like a robot
that you can tell to build a layer
at a time from the cards of your
choice.
http://robotclipart.com/1024/3d-clipart-of-a-striped-silver-and-white-aomaru-robot-holding-a-joker-playing-card-by-leo-blanchette-314.jpg

3. Containers are lighter, faster VMs
That's not enough to explain the “container craze”
● Code Portabilty: developer environments can be cloned to
each other or into production
● Light Weight: devs can run multi-tier app on laptop
● Better Performance: less overhead, faster start-up
It's not all sunshine & rainbows: security is unproven,
networking and storage are behind and it's still mostly about
Linux

4. Workflow, not Containers vs VMs
VMs, once the backbone of “cloud computing”, have
encourage application automation (DevOps) and
decomposition (micro services) approach to flourish.
These changes increase portability and decrease lock-in
especially since Linux is so widely adopted for cloud
workloads.
It's really about workflow and tooling not environment
Google proved containers work at massive scale with highly
automated tooling. The tooling accelerates app life-cycle.
Why now? This transformation was already happening at
the platform layer (CloudFoundry, Heruko, etc) but Docker
made it more accessible to Developers.

5. Application Decomposition
The 90s “service oriented architecture” is now called “micro-services”
Aka: the 90s called and they want their SOA back.
Fundamentally, all applications are composed
of lots of individual parts.
Ideally, these parts are “loosely coupled.”
Decomposition simply means repackaging the
loosely coupled parts into descrete units so
they can be managed individually and
accessed over network connections.

6. A Big, Automated Lifecycle
All the King's Horses and all the King's Men...
Once we've decomposed our application, now we have a lot of
little parts floating around!
Coordinating all those parts is Orchestation.
If Done right, applications easier to deploy & maintain.
The platform manages:
– Dependencies between components
– Order of operation for deployment
– Scale up and down of resources
– Tune and optimize performance

7. What is Kubernetes (aka K8s)
● Describes how components are connected
● Deploys/maintains component instances
● Relies on
– containers to package runnable application bits
– “meta data” files to describe relationships (YAML)
– correctly configured platform, storage and networks
● Key Ecosystems
– Advanced orchestrators and tools to run k8s
– Trusted providers of containers

8. It's not.
PaaS is specialized version of container orchestration.
PaaS' key benefit is being opinionated
A clear pattern & structure makes it easier for
developers to learn and use the platform.
Kubernetes is not opinionated, it's very flexible.
Most enterprises will want to consume it through add-
on management tools.
Different than Platform (PaaS)?

9. Why is this hard?
1) Apps have to be (re)written for the platform
2) Lots of Confusion
1) Architecture patterns are still evolving
2) Container market is very competitive
3) Competing non-Containerized approaches
3) Unclear how to solve networking, storage &
security
4) Need tools to “fire break” failures
5) Distributed systems are notoriously tricky

10. Why is this worth investment?
Sigificant gains in speed and performance
• Better application development life-cycle.
Winning developers often means winning the
data center.
• Larger developer communities (less skills)
• Mortals can built & maintain scale operations
• More portability between systems
• Better use of infrastructure (density, on metal)

11. Adjacencies?
Fancy word for “additional services”
The unique part of an application is small.
The standard stuff is done in standard ways by
services that should to “just work” and “just scale”
There is money in the supporting services that
run these applications like data storage,
networking and analysis.
Container orchestration is just part of a larger
system of services that are required.
Adjacencies are essential and persistent.

12. Are we there yet?
It is possible that we have a “silver bullet” to
allow mortals to create distributed systems
This is still early days in the evolution cycle
Google's success with Kubernetes assumes a
lot of hidden disciplines and operational
behaviors that may be hard to replicate.
The ecosystem is very noisy with a lot of
investment. That speeds evolution at the price
of added user confusion.
But yes, this is a long-term change in IT.

13. Demo...

14. Kubernetes Meta Data
apiVersion: v1
kind: ReplicationController
metadata:
name: redis-master
labels:
name: redis-master
spec:
replicas: 1
selector:
name: redis-master
template:
metadata:
labels:
name: redis-master
spec:
containers:
- name: master
image: redis
ports:
- containerPort: 6379

15. Kubernetes Command Line
[root@demohost ~]# vi example.yml
[root@demohost ~]# kubectl create -f example.yml
replicationcontrollers/redis-master
[root@demohost ~]# kubectl get rc
CONTROLLER CONTAINER(S) IMAGE(S) SELECTOR
REPLICAS
redis-master master redis name=redis-master 1
[root@demohost ~]# kubectl get pods
NAME READY REASON RESTARTS AGE
redis-master-t94pf 0/1 Pending 0 17s