Network policies for traffic control in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Kubernetes Network Policy?

A Kubernetes Network Policy is a set of rules that controls how pods communicate with each other and with other network endpoints. It acts like a firewall inside the cluster to allow or block traffic.

beginner

Which Kubernetes resource is used to define traffic rules between pods?

The NetworkPolicy resource is used to define rules that specify allowed inbound and outbound traffic for pods based on labels and ports.

intermediate

What does the podSelector field do in a Network Policy?

The podSelector field selects which pods the policy applies to by matching labels. Only pods matching this selector are affected by the policy rules.

intermediate

How does a Network Policy affect traffic if no policies are applied to a pod?

If no Network Policies select a pod, then all traffic to and from that pod is allowed by default. Policies only restrict traffic when applied.

beginner

What is the difference between ingress and egress rules in Network Policies?

Ingress rules control incoming traffic to pods, while egress rules control outgoing traffic from pods.

What does a Kubernetes Network Policy primarily control?

A CPU usage of pods

B Network traffic between pods

C Storage allocation for pods

D Pod scheduling on nodes

Network Policies control how pods communicate by allowing or blocking network traffic.

Which field in a Network Policy specifies which pods the policy applies to?

A podSelector

B namespaceSelector

C policyTypes

D metadata

The podSelector field selects pods by labels to apply the policy rules.

If a pod has no Network Policies applied, what is the default behavior for its traffic?

A Only ingress traffic is allowed

B All traffic is blocked

C All traffic is allowed

D Only egress traffic is allowed

Without any Network Policies, pods accept all traffic by default.

What does an ingress rule in a Network Policy control?

A Node network settings

B Outgoing traffic from pods

C Pod resource limits

D Incoming traffic to pods

Ingress rules specify what incoming traffic is allowed to pods.

Which Kubernetes resource would you create to block all traffic to a pod except from a specific namespace?

A NetworkPolicy with namespaceSelector in ingress

B PodSecurityPolicy

C ConfigMap

D ServiceAccount

NetworkPolicy with a namespaceSelector in ingress rules can restrict traffic to pods from specific namespaces.

Explain how Kubernetes Network Policies control pod communication and why they are important.

Think of Network Policies as rules like a gatekeeper for pod traffic.

Describe the difference between ingress and egress rules in Network Policies with an example for each.

Ingress is like who can visit your house; egress is where you can go out.