Kubernetes Security Best Practices

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With the introduction of containers in the market, the way of creating and deploying applications has completely changed. If you are handling fewer containers, it will work fine, but problems arise when the number of containers grows. Then, we need to manage the containers on a large-scale. To solve this managing problem, we have Kubernetes.

Kubernetes is the world’s leading container orchestration tool that helps in managing and deploying containerized applications on various platforms. However, it comes with security challenges, which we will discuss in detail as well as the security practices we can implement to avoid these issues.

What is Kubernetes?

Kubernetes is an open-source tool that helps in orchestrating container workflows. You can easily manage large container clusters and several hosts running containers efficiently using the Kubernetes technology. Kubernetes enables you to manage and control various containers related tasks, like scheduling, load-balancing, and distribution.

Kubernetes ensures deploying and managing cloud-native applications anywhere without relying on the underlying infrastructure. Kubernetes technology is gaining much popularity and has increased from 58 percent to 91 percent by 2020. Also, Kubernete’s skills are in great demand by companies to make their working process more comfortable and efficient.

Advantages of Using Kubernetes

Kubernetes allows you to shy away from the traditional VM technology for running individual applications. Using Kubernetes has reduced the sysadmin costs and has taken the service to the next level. It also overcomes the networking and data protection issues. Below are few benefits of Kubernetes:

  • You can set the scalability policy once you deploy the containers. It ensures you can dynamically scale your resource requirements accordingly.
  • Configuration files are used to map the container relationships so that nothing will be missed out while running containers.
  • It will save you a lot of time by automating the development and deployment process across different phases of the container.
  • You can create various container versions to ensure that you can rollback to the earlier version of the deployment that does not run as expected.
  • You can easily add any number of nodes within the cluster and adjust the available resources.
  • It helps in updating the container images whenever it is available and destroys the old image.
  • You can easily change your Kubernetes vendor as you do not have to depend on the vendor for any specific service and running containers.
  • You can deploy any type of application quickly without focusing on the system configurations.

Kubernetes Security Risks and Challenges

  • Running Multiple Containers

Containers leverage microservices architecture to ensure incredible speed, portability, and scalability. But, they can also create blind spots for the attackers. Once you deploy thousands of containers, it will become challenging to maintain sufficient visibility into your cloud-native architecture.

Containers are highly distributed over the network, making it difficult to investigate which container is at risk and create vulnerability of all the containers on the network. This situation will create a risk for the organization.


  • Misused Images can Create a Risk

Every company must ensure that all the container images are built and stored within the trusted image repositories. Images should be created using a secure and approved base image. You must scan the images regularly and make sure you use only authentic images while launching containers in the Kubernetes environment.


  • Containers Interact with Each Other

For proper deployment, each container interacts with other containers along with other internal or external endpoints. If one of the containers is hacked, there are chances that the virus will move across the interacting containers within the environment.

Within the sprawling containerized environment, it is challenging to implement network segmentation due to the complex configuration of the containers.


  • Kubernetes Default Settings are Not Secure

To facilitate the DevOps approach, Kubernetes helps in speeding up the application deployment and simplifying the management of operations. Kubernetes has rich controls that can secure the cluster and containerized applications.

Kubernetes provides network policies that define how containers will communicate with others based on the assets defined within the network. By default, Kubernetes do not apply any network policy to pods to communicate and open containers to risk.


  • Compliance Challenge

Some of the cloud-native environment running containers come with security and compliance challenges. As Kubernetes ensures compliance, they should display the proof.

They must ensure that the Kubernetes environment offers controls that are explicitly written for traditional applications and ensure the monitoring compliance should be done automatically for successful operation.

Kubernetes Security Best Practices

Build Phase

You can start implementing Kubernetes security practices from the build phase along with securing your container images. Once you fix the security issues at this phase, there are fewer chances of getting more security fixes at the next level.

At this stage, you need to make sure that images are built securely and check the same for any vulnerabilities. You can follow the below practices at the build phase:

  • Use Minimal Base Images – You should avoid using images from OS package managers as they can carry unknown vulnerabilities. Still, if you want to use the OS package manager, then you should remove it at the next step. You should try using distroless images.
  • Do Not Add Unnecessary Components – You should avoid using debugging tools from the containers running in production. For example, Curl may be useful for the attackers.
  • Always Use Updated Images – Ensure you use the latest version of the images and components while running containers to ensure efficient working.
  • Scan Images for Vulnerabilities – Scan the images to identify vulnerabilities to fix them. You should check vulnerabilities in the OS package.

Deploy Phase

Configure the Kubernetes infrastructure securely before deploying the workloads. To ensure security, you must check what you are deploying and how. After that, you can identify and resolve the security policy regulations.

You must consider what you are deploying, where you are deploying, how you are deploying, what it is accessing, and whether it is following the compliance policy or not. Below are some practices that you should consider at the deployment phase:

  • Isolate the Sensitive Workloads- You can use namespaces to isolate the Kubernetes resources, which refers to the network-related policies, restricting access control, and other security controls. Isolating workloads will minimize the attack and destructive actions by attackers.
  • Network Policies to Control the Traffic – Every container and pod interacts with other running containers within the environment. You can implement network segmentation that can prevent lateral container movement.
  • You need to make sure that you include only those secrets that are not useful for the attackers and avoid unnecessary exposure.
  • The container privileges can impact your security risks. Make sure you provide minimum required privileges to the container to complete its intended tasks. You should not run the container with root access, try using a read-only root filesystem, avoid using the host network, and avoid using unnecessary Linux capabilities.
  • Try to avoid deploying the code from unknown sources and only use the images from known sources.
  • You must label your deployments with name, email alias, or team name for that application. In case of failure, the responsible team will be notified with proper alerts.
  • You must implement role-based access that controls the authorization to access the Kubernetes cluster.

Runtime Phase

Containerized applications are more exposed to various security challenges. You need to check the visibility of your running environment to get the defect and resolve it.

After you resolve most of the issues at the build and deployment phases, there are fewer chances of having security incidents at the runtime and thus, fewer efforts are required. Below are the practices that can be implemented at the runtime phase:

  • You can use the build and deploy phase information to check for the expected results to detect any unexpected activity.
  • You should monitor the running deployments for any new bugs other than the vulnerabilities in the container image.
  • You should implement security context to the containers to limit their capabilities. You can control attacks on the pods based on their privileges.
  • Kubernetes should scale the suspicious containers to zero or kill them to restart the application instance again.

Infrastructure Security

  • Make sure to regularly update Kubernetes to the latest version whenever possible.
  • Ensure you configure the Kubernetes API server in a secured manner.


Kubernetes is widely used within organizations to orchestrate containers efficiently. It has changed the working of DevOps in deploying and managing containerized applications in any environment. The container orchestration system, however, poses some challenges that we have discussed before.

Also, you may face various challenges at different phases of the container lifecycle. We have mentioned various security practices that can be implemented throughout these phases, to ensure a secure working of containers.

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