Containers, Cluster and Kubernetes - How Docker, containers and cluster management are changing the way that we design and build distributed systems.

1. Containers, Clusters &
Kubernetes
Brendan Burns
Staff Software Engineer

2. Motivations
Make writing
BigTable a CS 101
Exercise

3. What is a container?
What is a container?
● Lightweight Linux environment
● Hermetically sealed, deployable
application
● Introspectable, runnable artifact
● Recently popularized by Docker

4. What is a cluster?

5. The transition to logical compute
VM
Container
Container
Container
Logical Compute Substrate
Container
Container
Container
Container
Container
Container
Container
Container
Container
Container
Container
Container
Container
Container
Container
VM VM VM VM VM VM VM VM VM

6. Modular Application Design
VM
Database
Dependencies
WebServer
MiddleWare
Database
Container
Dependency
VM
WebServer
Container
Dependency
Middleware
Container
Dependency
vs.

7. Modular Scaling
VM
Datab
ase
Depende
ncies
WebSer
ver
Middle
Ware
Database
Container
Dependency
WebServer
Container
Dependency
Middleware
Container
Dependency
vs.
VM
Depende
ncies
WebSer
ver
Middle
Ware
Datab
ase
VM
Depende
ncies
WebSer
ver
Middle
Ware
Datab
ase
Middleware
Container
Dependency
WebServer
Container
Dependency
VM VM
WebServer
Container
Dependency

8. What is Kubernetes?
● Open source container cluster manager
● Inspired by the technology that drives
Google
● Runs anywhere:
○ Public Cloud
○ Private Cloud
○ Bare Metal
● Strong ecosystem
○ Partners: Red Hat, VMWare, CoreOS,
Microsoft, ...
○ Community: Client libs, integration, ...

9. The Cloud Dichotomy
IaaS
PaaS

10. A brief history of programming languages
Assembly
Assembly
PostScript

11. A brief history of programming languages
Assembly
OAbsjseecmt Oblryiented Languages
PostScript

12. The Cloud Dichotomy
IaaS
ICaaaaSS
PaaS

13. Components

14. Components: Pods
Kubernetes Pod
Container-1 Container-2
Shared
Volume(s)

15. Components: Sidecars
Kubernetes Pod
Serving
Container
Git Sync
Container
Shared
Volume
Git Repo
Sidecars Extend and Enhance

16. Components: Adapters
Kubernetes Pod
Redis Service Redis
Adapter
Kubernetes Pod
MongoDB
Service
MongoDB
Adapter
Kubernetes Pod
MySQL
Service
MySQL
Adapter
Monitoring Service
Adapters Normalize and Abstract

17. Components: Ambassadors
Kubernetes Pod
Frontend
Container
MySQL
Ambassador
Container Container Container
Read Slaves
Container
Write Master
localhost
Ambassadors Proxy and Represent

18. Encapsulation

19. Abstractions, ftw! : Reliability
{Container, Health Check}
Kubernetes
Container
Web: http://<container>/some/path/to/health
Shell: exec /some/path/health.sh
TCP: open <container> <port>

20. Abstractions, ftw! : Replication
{Template, Identifier, Num. Replicas}
Replication
Controller
Container Container Container Container

21. Abstractions, ftw! : Services
{IP:Port, Identifier, Name}
Discoverable
Service
Container Container Container Container
DNS
Service IP
Container

22. Patterns

23. Patterns and Interfaces: Master Election
Lock Service
Cluster Manager
http://<container>/healthz
Container Container Container Container

24. Patterns and Interfaces: Master Election
Lock Service
Cluster Manager
http://.../master?master=container1
Container Container Container Container

25. Patterns: Sharded HTTP Service
http://foo.com/alpha
http://foo.com/beta
http://foo.com/gamma
Kubernetes Service
Container Container Container
http://foo.com/alpha http://foo.com/beta http://foo.com/gamma

26. Patterns: Hot Sharded HTTP Service
http://foo.com/alpha @ 20 qps
http://foo.com/beta @ 5 qps
http://foo.com/gamma @ 5 qps
Kubernetes Service
Container Container Container
http://foo.com/alpha http://foo.com/beta
http://foo.com/gamma
http://foo.com/alpha

27. Patterns: Bigtable
Kubernetes Service
http://.../api/get?key=<key>
http://.../api/set?key=<k>&val=<v>
Container
http://.../manage/shard/<shard>/split
http://.../manage/shard/<shard>/merge
http://.../manage/shard/<shard>/load
http://.../manage/shard/<shard>/unload
Data
Interface
Management
Interface

28. We’re building an os for the datacenter.
Join us!
#google-containers on FreeNode
https://github.com/GoogleCloudPlatform/kubernetes
https://cloud.google.com/container-engine/

29. Stop