Kubernetes Networking Flashcards
1
Q
How are pods connected regarding networking, ip-address and communication in Kubernetes?
A
- Kubernetes assigns a unique IP address to each Pod
- Containers in a pod share the same ip-address, because they share the same namespace
- thus they can refer to each other by localhost
- Containers in a pod can expose unique ports and become accessible through the same pod-IP
2
Q
In addition to Container Network Interface, what requirements need to be fulfilled by networking driver developers in Kubernetes?
A
- all pods on a node can communicate with all pods on all nods without Network Address Translation (NAT)
- Agents on a node (kubelet, system daemons, …) can communicate with all pods on that node
- the pods in the host-network of a node can communicate with all pods on all nodes without NAT
3
Q
What are projects implementing the Kubernetes CNI and what do they build?
A
- are in fact Software Defined Networking Implementations
- which are deployed on a Kubernetes Cluster as plugins
- that build a private, virtual, isolated network layer for Pod-to-Pod communication
4
Q
What are examples for CNI-implementations?
A
- Azure CNI for Kubernetes
- Calico
- Cilium
- Flannel