Network policies for security 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 control how pods communicate with each other and with other network endpoints. It helps secure the cluster by restricting traffic.

beginner

Which Kubernetes resource defines network policies?

The resource is called NetworkPolicy. It is a Kubernetes API object used to specify how groups of pods are allowed to communicate with each other and other network endpoints.

intermediate

What does the podSelector field do in a Network Policy?

The podSelector field selects the pods to which the network policy applies. Only the selected pods will have the traffic rules enforced.

intermediate

How do you allow incoming traffic only from pods in the same namespace using a Network Policy?

You create an ingress rule with from specifying podSelector matching the pods in the same namespace. This restricts incoming traffic to only those pods.

beginner

What happens if no Network Policy selects a pod?

If no Network Policy selects a pod, then by default all traffic is allowed to and from that pod. Network Policies only restrict traffic for selected pods.

What is the default behavior for pod traffic if no Network Policy is applied?

A All traffic is allowed

B All traffic is blocked

C Only ingress traffic is allowed

D Only egress traffic is allowed

By default, Kubernetes allows all traffic to and from pods if no Network Policy selects them.

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

A podSelector

B namespaceSelector

C policyTypes

D ingress

The podSelector field selects the pods that the Network Policy will apply to.

How do you specify that a Network Policy should restrict outgoing traffic?

A Use the ingress field

B Use the egress field

C Set policyTypes to Ingress only

D Set podSelector to empty

The egress field defines rules for outgoing traffic from selected pods.

What does setting policyTypes: ["Ingress"] do?

A Blocks all traffic

B Restricts only outgoing traffic

C Restricts only incoming traffic

D Allows all traffic

Setting policyTypes to Ingress means the policy controls only incoming traffic.

Which selector allows you to restrict traffic from pods in a different namespace?

A podSelector

B policyTypes

C ipBlock

D namespaceSelector

The namespaceSelector selects pods based on their namespace, allowing cross-namespace traffic control.

Explain how Kubernetes Network Policies help secure pod communication.

Think about controlling who can talk to whom inside the cluster.

Describe the difference between ingress and egress rules in a Network Policy.

Consider traffic direction relative to the pod.