Kubernetes is an open-source platform for automating deployment, scaling, and operations of containerized applications. It provides basic mechanisms such as service discovery, load balancing, failure recovery, horizontal scaling, and self-healing. Key Kubernetes concepts include pods, labels, replication controllers, services, and namespaces. Pods are the basic building blocks that can contain one or more containers, which are scheduled together on nodes and share resources. Kubernetes handles tasks such as health checking, restarting containers, and load balancing.

1. State-of-the-art
Container Management Platform
08 / 2016

2. About me
● Name: Chu Duc Minh - Age: 32
● Cloud Chief Architect @ VCCorp
● Head of Cloud Solutions department @ VCCloud
● Expertise: SDN, Storage, OpenStack, Kubernetes, Hashicorp tools
● Passion: Distributed System, Cloud &
Infrastructure Technologies

3. Ok, now we have containers...
Isolation: Keep services from interfering with each other
Scheduling: Where should my service be run?
Lifecycle: Keep my service running
Discovery: Where is my job now?
Constituency: Which (containers) is part of my service?
Scale-up/down: Making my services bigger or smaller
Auth{n,z}: Who can do things to my service?
Monitoring: What’s happening with my service?
Health: How is my service feeling? (well or sick?)

4. Google and Containers

5. Kubernetes (short-name: k8s)
● Project was started by Google in 2014.
● Kubernetes is an open-source platform for automating deployment,
scaling, and operations of application containers across clusters of
hosts.
● Provides container grouping, load-balancing, auto-healing, scaling.
● Can run on anywhere: Public Cloud (AWS, GCE,..), Private Cloud
(OpenStack), Baremetal, v.v…
● Extensible: Modular & Pluggable & Hookable architecture

6. Community

8. Design Overview
“ Kubernetes is primarily targeted at applications composed of
multiple containers, such as elastic, distributed micro-services.
It is also designed to facilitate migration of non-containerized
application stacks to Kubernetes.
…[Kubernetes] provides ways for containers to find and
communicate with each other in relatively familiar ways. ”
https://github.com/kubernetes/kubernetes/tree/master/docs/design

9. How does it work?

10. Kubernetes Architecture

11. Key concepts
● Pod - A group of co-living containers
● Labels - For identifying pods
● Replication Controller - Manages replication of pods
● Service - A logical set of pods and way to expose them
● Namespaces - Way to seperate environments, projects,
applications,…
● Service Discovery - By cluster-DNS

13. Pod
Small group of containers & volumes
Tightly coupled:
same node
The atom of cluster scheduling & placement!
Shared network namespace:
share IP address & localhost
Example:
Pod 1: data puller & web server
Pod 2: web server & log shipper

14. Pod

15. Pod

16. Pod networking
Pod IPs are routable
Docker default is private IP
Pods can reach each other
without NAT
even across nodes
No brokering of port numbers
This is a fundamental requirement
several SDN solutions

17. Labels
➢ Label is simple key/value pair
➢ Attached to any API object
➢ Generally used for represent identity
➢ Queryable by selectors:
think SQL ‘select ... where ...’
➢ The only grouping mechanism of K8s:
pods under a ReplicationController
pods in a Service
capabilities of a node (constraints)

19. Replication Controller
Replication Controller
- Desired = 4
- Current = 4

20. Replication Controller
Replication Controller
- Desired = 4
- Current = 4

21. Replication Controller
Replication Controller
- Desired = 4
- Current = 3

22. Replication Controller
Replication Controller
- Desired = 4
- Current = 4

23. Replication Controller

24. Service
A group of pods that act as one == Service
group == selector
Gets a stable virtual IP and port
called the service portal
also a DNS name
VIP is captured by kube-proxy
watches the service constituency
updates when backends change

26. ● By teams
● By projects
● By operators
● By environments
○ Dev
○ Test
○ Staging
○ Production

27. Server-side Service Discovery

28. Server-side Service Discovery

29. Rolling-update
...is a deployment pattern.
Update microservices to new version gracefully!
Also rollback too.

30. Deployment
More deploy patterns is supported!
Blue/Green
Canary
with many customizable options.
Ref: http://kubernetes.io/docs/user-guide/deployments/

31. Secrets Management
“Secrets” like username/password, API key, SSL certificate, v.v..
Secrets only stored in Kubernetes and only used by
allowed services.
[Encrypted-] secrets no more stored in gitRepo, sysadmin’s laptop,
volume on a storage, v.v…
→More secure!
Pod can access to allowed secrets via:
Files (in pod’s mounted-volume)
ENV vars

32. Secrets Management

33. Secrets Management

34. Monitoring
Metrics
Log

37. Pluggability
You can choose [almost] any technology you want!
networking (Flannel, Calico, OpenContrail, Weave, Romana, v.v..)
storage (NFS, GlusterFS, amazonEBS, gcePersistentDisk, RBD, v.v..)
container (Docker, rkt, HyperContainer)
And any cloud-provider you want!
AWS / GCE / Azure
OpenStack / CloudStack
And extend K8s’s scheduler via multi mechanisms
& over multi dimensions.

38. Integrate with OpenStack (/AWS/GCE/Azure)
Auto-provision and configure:
❖ Load-balancer (LBaaS @ OpenStack)
❖ Volume (Cinder @ OpenStack)
❖ etc
…magically!

39. Minikube
➢ Minikube starts a single node kubernetes cluster locally for purposes
of development and testing.
➢ Packages and configures a Linux VM, Docker and all Kubernetes
components, optimized for local development.
➢ Supports:
○ DNS
○ NodePorts
○ ConfigMaps and Secrets

40. Conclusion
Kubernetes is a Toolkit for running distributed systems in production!
Co-locating helper processes Naming and discovery
Mounting storage systems Load balancing
Distributing secrets Rolling updates
Application health-checking Resource monitoring
Replicating application instances Log access and ingestion
Horizontal auto-scaling Support for introspection
and debugging

41. Q & A

42. This page is intentionally left blank.

43. One last thing...
Kubernetes-based PaaS

44. References
https://www.youtube.com/watch?v=06InE1XTlIo
http://www.slideshare.net/brendandburns/defrag-2014-41815642
https://www.youtube.com/watch?v=qCxYjq7EBHc
http://www.slideshare.net/imesh/an-introduction-to-kubernetes
http://www.slideshare.net/KasperNissen1/google-cloud-platform-and-kubernetes
https://www.nginx.com/blog/service-discovery-in-a-microservices-architecture/
http://martinfowler.com/articles/microservices.html
https://www.youtube.com/watch?v=DGlQgNmobuc