This document provides an introduction to Kubernetes and Container Network Interface (CNI). It begins with an introduction to the presenter and their background. It then discusses the differences between VMs and containers before explaining why Kubernetes is needed for container orchestration. The rest of the document details the architecture of Kubernetes, including the master node, worker nodes, pods, labels, replica sets, deployments, services, and how to build a Kubernetes cluster. It concludes with a brief introduction to CNI and a call for questions.

1. An Introduction to Kubernetes and CNI

2. About Me
• 鄭偉聖, SAM
• CS student in NCTU
• Intern in National Center for High-performance Computing(NCHC)
• Intern in Industrial Technology Research Institute (ITRI)
• Familiar with OpenStack, Docker, Kubernetes
• Golang and Python
• Email: kweisamx.cs05g@g2.nctu.edu.tw
• GitHub: github.com/kweisamx

3. VM v.s Container

4. 4
Why we need Kubernetes ?

5. Why we need Kubernetes ?

6. Agenda
Introduction Kubernetes
Architecture
How to build Kubernetes cluster
Application
Conclusion & QA

7. Introduction to Kubernetes
 100% opensource, written by Golang
 Platform for automating, deployment, and operation
 Inspired and informed by Google’s experiences and “Borg”
 The name is mean ”helmsman” and “pliot”
 Aka k8s , replace “ubernete” with 8

8. Architecture
 Master-Slave
 Master used to controller the cluster and offer API
 Node mostly run the container to offer service

9. Architecture

10. Kubernetes Master
 Etcd: Use to store the cluster status
 ApiServer: Use Restful Api to get informati
on or post request with json
 Controller Manager Server: Controller the
cluster
 Schedular: schedule resource for container

11. Kubernetes Node
 Kubelet: connect with apiserver, handle d
ata, volumn, image, status for container
 Kube-proxy: handle the service routing, an
d support Load Balance

12.  A Group of co-located containers(one or more)
 Shared the same value and network namespace/ip port
 Restart pofile
 Healthy
 Templates(yaml)
12
Pod

13. Pod

14. Pod

15.  Arbitrary metadata
 The connect with Replication controller and pods
 key/value pairs
 identify a set of objects via a label selector
15
Label

16. Label

17. • Ensures that a specified number of pod “replicas” running at any time
• Flexible scale
• Auto change the replica
• Rolling Update
Replica Set

18. Replica Set

19. Replica Set

20. Replica Set

21. 21
Replica Set

22. 22
Replica Set

23. • We create the pod , which pod of label is test:rc
• And then we change the pod’s labels from rc to rc2
• Because kubernetes get the information that no pod label is “rc”, so it
create the new one
23
Replica Set

24. • And we delete the pod
• Yes, the pod is different, that because the
ReplicationController keep number is 1 of the pod
which label is “rc” 24
Replica Set

25. • And we can also change the number of replica
• Ofcourse, you can shrink the number of replica
25
Replica Set

26. • Use by deployment and ReplicationController
• Update period
• Reverse the version(if you need)
Rolling Update
ServiceService

27. • Kubernetes recommand us use deployment to build our
container cluster
• All feature of replica set
• Provides declarative updates for Pods and Replica Sets
• More Powerful
Deployment

28. • Test: rolling update
– Set Image
– Replace
• Change the yaml to update by use <kubectl replace –f >
– Edit
• Kubectl edit deploment <your deploment>
Deploment

29. Deploment

30. • Edit
Deploment

31. • Defines a logical set of Pods and a policy by which to access them.
• A service rule defines a TCP or UDP port reservation
• Provides a way for applications running in containers to connect
• Use labels
• Clutser IP
31
Service

32. Service

33. Service

34. How to Build Kubernetes?
 Kubeadm : quickly, easy , but not recommended to build production
cluster, master don’t have high availability
 Kubespray: Use with Ansible, and support many add-on, can build for
production, but recommend to familiar with Ansible
 Kops: Use in Cloud like AWS , GCP, easy to build your cluster
 Bootkube: Now in kubernetes-incubator, can be used to generate all of
the necessary assets for use in bootstrapping a new cluster
 Kubernetes the Hard Way: The most hard way to bulid, but you can
learn much of kubernets

35. • The simple interface between container runtime and network implement
• Originated at CoreOS as part Rkt
• CNCF project
Container Network Interface

36. Container Network Interface

37. Thank You!
Q&A