Review Kubernetes history as the project moves towards a 1.0 release. Video: https://www.youtube.com/watch?v=_JDUbitRYws Join DevOps Exchange London here: http://www.meetup.com/DevOps-Exchange-London Follow DOXLON on twitter http://www.twitter.com/doxlon

1. The Road to 1.0
Kubernetes — DOXLON Meetup, June 2015
Craig Box, Solution Engineer, Google Cloud Platform
#kubernetes kubernetes.io twitter.com/craigbox

2. Kubernetes
A recap
Greek for “Helmsman”:
the root of the word “governor” and “cybernetic”
● Container orchestrator
● Builds on Docker containers
○ also supporting other container technologies
● Multiple cloud and bare-metal environments
● Supports existing OSS apps
○ cannot require apps becoming cloud-native
● Inspired and informed by Google’s
experiences and internal systems
● 100% Open source, written in Go
Let users manage applications, not machines

3. A small group of
tightly coupled
containers
Example:
static site generator &
web server
A loop that drives
current state towards
desired state
Example:
replication controller
A set of running pods
that work together
Example: load-
balanced backends
Arbitrary metadata to
organize components
Example:
phase=production
role=frontend
Pod
Replication
Controller Service Labels

5. ● Open sourced in June, 2014
● Google launched Google Container Engine (GKE)
○ hosted Kubernetes - don’t think about cluster setup
● Lots of partners
○ RedHat (OpenShift 3 PaaS)
○ CoreOS (Tectonic turn-key Kubernetes deployment)
○ Mesosphere (Kubernetes on Mesos - share with non-container workloads)
○ Mirantis (Murano Kubernetes on OpenStack)
● Driving towards a 1.0 release
○ O(100) nodes, O(30) pods per node
○ stable APIs (v1)
● Roadmap on GitHub
Status and plans
Kubernetes

6. Partnerships
Kubernetes

7. Some history

8. Project Seven: "a more attractive Borg"

9. Google's data centers were designed from the ground up for this approach
to management
No matter how cheap, how fast or how reliable hosting is, no-one wants
lock-in to a single provider
What we did needed to be:
● built in the open
● pattern compatible with our approach to management
● address the mistakes of our previous systems
Help the world go Cloud Native
Why build Kubernetes?
(Micro) Service orientedDynamically scheduledContainer packaged

10. We wanted:
1. To write in Go, not Java or C++
● The container world was
moving to Go
● We knew Go was more
productive
2. To showcase the critical constructs
● Other systems were largely
monolithic
● Build the simplest thing that
works and grow from there
Help the world go Cloud Native
Why build Kubernetes?
3. "Over-modularity"
● Necessary for an ecosystem
to emerge
4. The cluster environment to be
lightweight
● Turn up and turn down as
easily as a VM

11. ● Mesos focus: schedulers and scheduling
○ Influenced by Google's published papers for Map/Reduce workloads
● Kubernetes focus: make it easy to build and manage distributed systems
○ scheduling is part of this, but not the only (or even primary) focus
○ services (provides discovery and load balancing)
○ master election
○ config store
○ easy private registry integration
○ namespaces
○ secrets
○ service accounts
○ volumes, and auto mount/unmount of persistent storage
Relationship to Mesos
Kubernetes

12. Relationship to Mesos
● No-one runs Mesos: they run Mesos + Chronos, Marathon, Aurora, or write their
own scheduler
● If you want Mesos, run Mesos + Kubernetes
● Mesos focus on what they’re great at (hardware abstraction and resource pooling)
● The Kubernetes community focuses on what it is good at
Target Kubernetes and you can run anywhere
Kubernetes

13. Spreading out now beyond Kubernetes
● appc and rkt
● Hyper, a new container VM runtime
● "The thinner the layer over Docker
that Kubernetes is, the better"
○ Proposal
● Watch this space for
Open Container Project!
Kubernetes opinions
The pod model

14. Kubernetes opinions
Or "do I need overlay networking?"
● Assume your application starts on
random ports
● In addition to requiring discovery for IP
addresses, you have to write custom
code (how do you convince redis to use
your lookup service for ports?)
● Ports are different between your replicas
● ACLs and QoS are harder to define for
the network without an identity for each
application
IP per Pod

15. Kubernetes opinions
Secrets
tmpfs-backed secret store
● Decouples secrets (passwords, SSH
keys, OAuth tokens, etc) from code
● Appears as a volume mounted to a
container within a Pod definition
● Never touches disk
● GitHub docs

16. “Don't make the same
mistakes we did. Only
make new ones!
– john wilkes, Principal Software Engineer

17. 1.0 release plans

18. Where are we now
Kubernetes 1.0
● v0.20 is 1.0 release candidate
○ If it’s work required for a 1.0 feature, or a bug that needs to be fixed for 1.0, we’ll
review and merge as usual
○ If it’s not required for 1.0, we will place the PR in the v1.0-post milestone and
return to it once 1.0 ships
○ Focus between RC and 1.0 will be testing, usability, reliability, performance and
documentation
● v1 API has been released
○ Thanks for all the feedback that shaped the API.
○ The intent is for the v1 API to be stable, with only backward-compatible changes,
for a sustained period of time.

19. Where are we now
Kubernetes 1.0
● 1.0 launch event in July
○ July 21st in Portland, OR - a part of OSCON
● 1.0 signifies that Kubernetes is ready for production workloads
● Already working on the v2 API and post-1.0 features

20. ● Network plugins
● Secrets
● Graceful termination
● Quota and other multi-user
● More volume types
● Auto-scaling
● Master and node upgrades
● Better batch job support
● Better performance and scalability
● High-availability masters
● Master election & other primitives
● Deployment controller
● Cluster federation: on-prem + multi-
cluster (“ubernetes”)
● Easier setup, and self-hosting
● rkt support
What's new (and coming)?
Kubernetes 1.0

21. Thank you!
Thank you!
#kubernetes kubernetes.io twitter.com/craigbox