What is Kube Bench? And Overview of Kube Bench

Table of Content

• What is a Kube Bench?
• Platforms available for CIS Kubernetes Benchmark Support
• Importance of Kube Bench
• Summary

To protect against potential security threats, Kubernetes must be configured securely in order to be effective. It is an excellent tool for managing containerized applications. Here’s where the Kube Bench comes in, Kube Bench is an open-source tool that measures whether a Kubernetes cluster has been configured securely according to the Kubernetes Benchmark developed by the Centre for Internet Security(CIS). In this blog post, we'll take a closer look at Kube-bench, how it works, and how you can use it to ensure that your Kubernetes clusters are configured securely.

What is a Kube Bench?

Kube Bench: It is basically a tool which assesses the Kubernetes cluster security by verifying against the Center for Internet Security (CIS) Kubernetes benchmark.  

To determine whether CIS Kubernetes Benchmark configurations are being met, the tool performs a series of automated checks against the Kubernetes API server, the etcd service, and worker nodes. Kubernetes Benchmark provides a comprehensive guide to securing a Kubernetes environment by highlighting best practices and security recommendations. 

In addition to running as a standalone tool or integrating with existing automation frameworks, Kube Bench can verify that a cluster is configured in a way that meets these recommendations. 

Detailed reports are included about the checks performed, along with recommendations for remediation of any failed tests. 

Kube bench can assist in ensuring that the Kubernetes cluster is configured securely and that containerized applications are secured in accordance with industry best practices. 

Kuber Bench CIS Benchmark:

A set of secured configuration criteria created for Kubernetes that are the result of a group consensus process.

There are two tiers of security settings offered by CIS benchmarks:

• Level 1(L1): This level suggests fundamental security standards that may be configured on any systems that must have minimal to no impact on functioning or operation.
• For locations demanding more security, Level 2 (L2), suggests security settings that might result in some functionality being reduced.

The example list of CIS requirements for the Kubernetes API server can be viewed in the following image.

Kubernetes CIS benchmarks include security advice and guidelines for the following:

Control plane node configurations and component suggestions are provided in the control plane components.

Worker Nodes: Kubelet setups and worker node settings.

RBAC, service accounts, Pod security guidelines, CNI and network policies, Secret Management, etc. are examples of policies.

A recommendation's status may be one of the following:

Pass - The suggested change has been made.

Failed because the advice was not followed.

N/A - The suggestion is unrelated to AKS because it concerns manifest file permission constraints. The control plane pods in Kubernetes clusters by default employ a manifest model and depend on documents from the node VM. These files ought to have particular permission specifications, according to the CIS Kubernetes benchmark. AKS clusters don't depend on documents in the node VM and instead, use Helm charts to distribute control plane pods.

Varies depending on Environment - AKS has no control over the recommendation; it is used in the user's particular environment. Whether or not a recommendation applies to the user's particular context depends on the benchmark score.

Similar Control: A different, equivalent method of implementation was used for the proposal.

Platforms available for CIS Kubernetes Benchmark Support:

Installation:

You can run Kube-Bench from inside a container. Firstly, run the container which will install Kube-Bench on the host. Then, download the config and test files from the cfg directory. Install the latest binaries from the releases page. Lastly, install the binaries and compile it from the source.

Install and download binaries:

You can run Kube-Bench release binaries manually and for this, you must have access to your Kubernetes cluster nodes. If you have Kubernetes services like AKS, GKE etc., then you will not be having access to the master nodes of the cluster and you will not be able to perform any tests on master nodes.

Firstly, login  to SSH 

For Ubuntu:

For RHEL:

Kube Bench can be run against a cluster in 2 ways: A). Through the Command Line B). Through inside a pod

A). Through Command Line: There are various steps involved in running a Kube Bench from a command line which are mentioned below:

Step 1: Firstly, log in to the control plane node and then create a Kube Bench directory.

Step 2:Then click on the  Kube-Bench release page and then select  the latest Linux binary link.

Step 3:Untar the binary link to /opt/kube-bench folder

Step 4: These are the benchmark variations for different versions and you will be able to see these structures once you click on the /opt/kube-bench link. And, then two folders will appear: cfg and Kube-Bench.

Step 5: You can now move these structures to /usr/local/bin and then, you can execute the Kube-Bench from any location of the system.

For example: Now to run benchmark checks using Kube-Bench, you should use generic config.yaml to run these benchmarks. Then lastly, these commands below will run the benchmark checks and will create the summary of remediation, checks etc.

How to examine AKS clusters?

AKS cluster that DevOps Starter automatically configures can be modified and examined. 

• Firstly, visit the Kube-Bench DevOps Starter dashboard.
• Then, Choose the AKS service on the right. A pane for the AKS cluster opens. You may take a number of activities from this view, including looking up logs, checking container health, and accessing the Kubernetes dashboard.
• Click See Kubernetes dashboard on the right. You might choose to carry out the steps to access the Kubernetes dashboard.

B). Through inside a pod:

So, you can run the Kube-Bench inside a pod too. This methodology is specifically useful for running CIS Benchmarks on Kubernetes clusters.

Alternatively, you can download the YAML to a file and then apply it if you wish to change it

Now, these reports of Kube-Bench will be available in pod logs too; for this list of the pods. Then, use the names of pods to get the logs.

Kube-bench is an open-source, user-friendly programme that you may use to execute the security checks outlined in the CIS Kubernetes benchmarks to see if your Kubernetes cluster has been installed securely.

It is important for anyone using Kubernetes to make sure their environment is secure and adheres to industry best practices by using Kube-Bench. Kube Bench helps you identify potential security vulnerabilities and take steps to mitigate them by checking your Kubernetes cluster against the CIS Kubernetes Benchmark. 

In conclusion, Kube-bench can be a useful tool if you're interested in DevOps and want to learn more about Kubernetes and security best practices. Also, to acquire the necessary knowledge and skills for a career in DevOps, think about signing up for a training course like StarAgile.

Importance of Kube Bench

Among the best tools for assessing the security postures of Kubernetes clusters is Kube-bench. With it, you can automate checks against industry best practices and security standards like the CIS Kubernetes Benchmarks to assure a cluster's configuration is up to snuff.

The results of these tests can identify potential security vulnerabilities and provide step-by-step recommendations for improving cluster security. It is important to regularly run Kube Bench to ensure Kubernetes clusters remain secure and compliant with security standards. 

Summary

As a DevOps professional, it's important to have a deep understanding of Kubernetes and the tools available to secure it. With the increasing demand for skilled DevOps professionals in the industry, obtaining a DevOps certification or training can be a great way to enhance your skills and advance your career. One such training provider is StarAgile, a leading training and consulting company that offers a comprehensive program. Their training covers various topics including Kubernetes, Docker, continuous integration and deployment, and more. By completing their DevOps training program, you can gain the knowledge and skills needed to excel in a DevOps role and increase your chances of landing a high-paying job.