20 Kubernetes Security Interview Questions and Answers

Kubernetes is a powerful container orchestration tool that is becoming increasingly popular in the DevOps world. As with any new technology, there is a learning curve when it comes to understanding and implementing Kubernetes security best practices. This is especially true when it comes to interviews, as you may be asked questions about Kubernetes security that you are not yet familiar with. In this article, we will review some of the most common Kubernetes security questions and how you should answer them.

Kubernetes Security Interview Questions and Answers

Here are 20 commonly asked Kubernetes Security interview questions and answers to prepare you for your interview:

1. What is a Kubernetes cluster?

A Kubernetes cluster is a group of servers that are used to run Kubernetes. A typical Kubernetes cluster will have a master server and a number of worker servers. The master server is responsible for managing the worker servers and the resources that they are running. The worker servers are responsible for running the actual applications and services that are deployed on the Kubernetes cluster.

2. Can you explain what RBAC is in the context of Kubernetes security?

RBAC is a method of controlling access to resources in a Kubernetes cluster. It stands for Role-Based Access Control. With RBAC, you can define roles that have certain permissions, and then assign users or groups to those roles. This gives you granular control over who has access to what resources in your cluster.

3. How can you make sure that containers are secure when running them on top of Kubernetes?

There are a few things that you can do in order to make sure that containers are secure when running them on top of Kubernetes. The first is to make sure that you are using the latest version of Kubernetes, as security patches are often released for new vulnerabilities. The second is to use a tool like Sysdig Secure to monitor and audit your containers for any suspicious activity. Finally, you can also use a tool like Aqua Security to scan your containers for known vulnerabilities and provide you with recommendations for how to fix them.

4. What is role-based access control? How does it work in the context of Kubernetes?

Role-based access control is a method of regulating access to resources based on the roles that users have within an organization. In the context of Kubernetes, role-based access control can be used to control which users have access to which parts of the Kubernetes cluster. For example, a user with the role of “cluster administrator” would have access to all parts of the Kubernetes cluster, while a user with the role of “developer” would only have access to the parts of the cluster that are relevant to their work.

5. What are namespaces and how do they relate to Kubernetes security?

Namespaces are a way of logically grouping resources in Kubernetes. By default, all resources are placed in the “default” namespace. However, you can create other namespaces for different purposes. For example, you might create a namespace for all resources related to a particular project.

Namespaces are important for security because they allow you to control access to resources. For example, you can grant a user access to a namespace, which gives them access to all resources in that namespace. This is a convenient way of managing permissions for large numbers of resources.

6. What’s the difference between an authorization policy and an admission controller? Which one would you prefer for different use cases?

An authorization policy is a set of rules that dictate who is allowed to access what resources within a Kubernetes cluster. An admission controller, on the other hand, is a piece of code that intercepts requests to the Kubernetes API and can reject or modify them before they are processed.

In general, you would prefer to use an authorization policy if you want to have granular control over who has access to what resources. Admission controllers can be used to enforce additional security measures, but they can also be used for other purposes such as rate limiting or logging.

7. What is Kubeadm? What is its purpose?

Kubeadm is a tool that helps you bootstrap a Kubernetes cluster. It can be used to initialize a cluster, install core components, and join worker nodes to the cluster.

8. Why should we use Kubernetes secrets instead of environment variables?

There are a few reasons for this. First, secrets are more secure because they are not exposed in your application’s source code. Second, secrets can be rotated without having to redeploy your application. Finally, using secrets gives you more fine-grained control over who has access to what information.

9. What is the best way to install certificates securely in a Kubernetes cluster?

The best way to install certificates securely in a Kubernetes cluster is to use the kube-cert-manager tool. This tool will help you to automatically generate and install certificates for your Kubernetes components, and will also help to keep your certificates up to date.

10. What is Pod Security Policy? When should it be used?

Pod Security Policy is a Kubernetes security feature that allows you to specify a set of security policies that must be met in order for a pod to be deployed. This can be used to ensure that pods are only deployed to nodes that meet certain security criteria, or to ensure that pods are not deployed with excessive privileges.

11. What type of encryption does Kubernetes support?

Kubernetes supports a number of encryption options, including symmetric encryption, asymmetric encryption, and certificate-based encryption.

12. What is Network Privilege?

Network privilege is the ability of a process to bind to or listen on a network port. By default, only processes with root privileges can bind to network ports below 1024.

13. Does Kubernetes provide a default service account for pods? If yes, then why should we create our own service accounts?

By default, Kubernetes does provide a service account for pods, but it is recommended that you create your own service accounts for greater security. The default service account is not as secure as it could be, and creating your own service accounts allows you to tailor the security to your specific needs.

14. What is Dynamic Admission Control?

Dynamic Admission Control is a Kubernetes security feature that allows you to control which pods are allowed to run on your cluster. This is done by creating and applying Admission Control Policies to your cluster. These policies can be used to whitelist or blacklist certain pod configurations, or to require certain security settings be met before a pod is allowed to run.

15. What is a RoleBinding?

A RoleBinding is a Kubernetes object that allows you to bind a role to a user or group of users. This gives those users the permissions that are defined in the role.

16. What is a ServiceAccount?

A ServiceAccount is an object in Kubernetes that provides credentials to pods so that they can communicate with other parts of the Kubernetes cluster. A ServiceAccount is essentially a way to give pods a way to authenticate themselves to the Kubernetes API.

17. What is a PodSecurityPolicy?

A PodSecurityPolicy is a policy object that defines the security settings for a pod. This includes things like which users and groups are allowed to access the pod, what privileges they have, and what types of containers are allowed to run in the pod.

18. What is CNI?

CNI is the Container Network Interface, and it is a set of standards for how to configure network interfaces for containers. CNI is used by Kubernetes to provide networking capabilities to containers.

19. What is Kubelet?

Kubelet is a Kubernetes agent that runs on each node in a Kubernetes cluster. It is responsible for maintaining the state of the pods and containers on that node. It also handles communication with the Kubernetes master to ensure that the node is kept up-to-date on the state of the cluster.

20. What is Client Certificate Authentication?

Client Certificate Authentication is a method of authenticating clients that uses certificates instead of username and password credentials. This can be used to provide an extra layer of security, especially in environments where sensitive data is being accessed.