Cloud Native: Kubernetes Network
Kubernetes
Part#1
1

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• 3 ERP (SAP-MM )/EAI Leader
• 2 End-To-End Business Integration Analyst
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• IT –
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erhwenkuo@gmail.com
2

• ”James” medium
• https://medium.com/@tao_66792/how-does-the-kubernetes-
networking-work-part-1-5e2da2696701

• , Kubernetes :
• Part#1 - Kubernetes
• Part#2 - Kubernetes Service Deployment Pod
• Part#3 - Kubernetes Ingress
I

• kubectl D SDK
• T b O
tT
Provision r RBAC Quota
PSP NetworkPolicy
• e
f s
DNS g
• Kubernetes h t K
API i t
n
• t
O Tt
• Kubernetes u
CI CD Workflow
FaaS OTS ChatOps
• Kubernetes CRI CNI
CVI Cloud Provider
t

Agenda
1. The basic knowledge of Kubernetes Pod
network stack
2. How Kubernetes Pod network works?
3. Conclusion
6

Kubernetes
“Pod”
7

• Pod Kubernetes
• Pod
• T PPod P
(network stack)
• (volume)

• Kubernetes Pod#1 2
• #1 nodejs REST API (port: 80)
• #2 mysql nodejs
• Kubernetes , #1 #2
•

• P Docker
•
eth0
docker0 bridge
• docker0 T
veth0

• docker0 veth0P
• 172.17.0.0/24
• IP docker0 172.17.0.1 veth0
172.17.0.2
• #1
veth0 docker0 eth0

• #2 #1 :
• docker0 veth1
• 172.17.0.0/24
• IP docker0 172.17.0.1 veth1
172.17.0.3
• #1 #2 (bridge)
• T P (bridge)
P

• T (bridge)
• P IP
•

• Docker
•
• P IP 172.17.0.2
•
d
• d
e
T

• Kubernetes
• Kubernetes pod (pause
container)
• : pod
P P

• pod
, .. P
• P T

Kubernetes
“Pod”
17

• Kubernetes
pod P OT
• KubernetesO Pod
Pod
• N pod A
AO WP O

• Kubernetes
• hA TO N
(A OVM k )
• d Pg i
Odocker
• Kubernetes
• f d W
e

• Kubernetes

• Kubernetes :
• A (private network segment)
10.100.0.0/24
• (router gateway)
10.100.0.1
• IP
10.100.0.2 10.100.0.3
• NPeth0 T
O

• Kubernetes pod P
• Kubernetes pod
Oveth0, Ndocker0
A P eth0

• eth0
10.100.0.2 N
(router/gateway) 10.100.0.1
• docker0 ( 172.17.0.1) eth0
pod A veth0 (
172.17.0.2)

• P
(pause container) ?
• pause container veth0 A
• veth0 A N
W(pause, container1,
container2)
• T O(shared network
stack) d

• (Routing) T
• N(network bridge)
W
• AO eth0 P
172.17.0.2T
Ndocker0 veth0
1
2
3
4

• N d fP
g T :
• N pod, nIP
172.17.0.2
• W Kubernetes O
pod docker0g e
routing
• routing
eth0 (10.100.0.2)
veth0 (172.17.0.2) g Aik
docker0 h veth0
1
2
3
4

e T
d
• AW e O
eth0 (ipN10.100.0.3) W
10.100.0.1
• eth0 e Wdocker0 P
172.17.0.1
… ! !!!!!!!

• docker0 k ngip
172.17.0.1? ?
• gip Ng ?
• Kubernetes hwo k
g Nroutingg ?
• e k hw k
g gPd i
!
• T o k ng podo
f W O A k
gpodg r t?

Kubernetes T N
• h k e
P k e f
• d O10.100.0.1 g
e f
W A i

• o fT n n
i ,
(overlay network)
• NKubernetesdk, h
pod n
• pod WO
pod t g
• r o A docker0”
h cbr P e custom
bridge

• Kubernetes P Pod-to-Pod
N W
• (CNI)
O 3rd partyN A
• CNI N
A N W N
T

•
ACNI :
• Calico
• Canal (Flannel for network +
Calico for firewalling)
• Cilium
• Flannel
• Kube-router
• Romana
• WeaveNet

•
ACNI :
• Calico
• Canal (Flannel for network +
Calico for firewalling)
• Cilium
• Flannel
• Kube-router
• Romana
• WeaveNet

• n
c
•
kubernets overlay
• lpod u s Kubernetes
i C o
(network route) o
• Kubernetes “pod ”

• How Does The Kubernetes Networking Work? : Part 1
• https://medium.com/@tao_66792/how-does-the-kubernetes-networking-work-
part-1-5e2da2696701
• Kubernetes -
• https://kubernetes.feisky.xyz/cha-jian-kuo-zhan/network
• Benchmark results of Kubernetes network plugins (CNI) over 10Gbit/s
network
• https://itnext.io/benchmark-results-of-kubernetes-network-plugins-cni-over-
10gbit-s-network-36475925a560

36
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