Harshit Mehndiratta
Harshit Mehndiratta
June 11, 2020
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5 minutes read

Top 5 Ways to Make Kubernetes Clusters More Secure

Orchestration tools such as Kubernetes provides phenomenal degrees of versatility and security when it comes to container deployment and cluster management. But to properly configure them requires intimate knowledge of the environment. So, in this blog, we highlighted the fundamental features which you can use to increase the overall security of your Kubernetes Cluster.

1. Fine-tune the Pod Security Policies

While deploying your pods, ensure that you appropriately configure the security parameters for your containers and volumes. A security parameter is a property defined in Kubernetes, which controls the security settings granted to that particular unit/container/volume.

Example of a pod in Kubernetes with security parameters

apiVersion: v1 kind: Pod metadata: name: transaction-service spec: containers: securityContext: readOnlyRootFilesystem: true runAsNonRoot: false

Here, readOnlyRootFilesystem implies whether a container will have the option to write into the exchange server Filesystem and runAsNonRoot specifier restricts the running of a user with administrator privileges which can offer access to sensitive data about users.

Ensure legitimate logging of pods-Access to a Kubernetes server using ssh should always go through an audit server to log access and all commands executed on the server. By monitoring users’ activities in the Kubernetes API, developers can break down the chain of events that prompted a potential issue. Also, continuous logging allows tuning of audit policies by defining how frequently events should be logged so that alerts can be issued.

2. Apply a Secret volume to your pods and containers

In Kubernetes, many engineers store sensitive data in Environmental Variables, which is not a secure practice. Using secrets that are mounted like volumes in pods will help keep the critical information safe and keep the sensitive data separate from a container image so that anybody with access to the container image cannot easily access the insights of that pod, which can increase security breaches.

Creating a secret volume in a cluster of containers decreases the chances of security breaches by isolating the procedures into an independent container and provides a front-end container that interacts with users while not providing the private data. This front end container approach increases the security of clusters, making it hard for a hacker to endorse an attack on the cluster.

3. Regularly Check Container Images for Authorization and Vulnerabilities

Having running software packages in pods with vulnerabilities can expose your container environment to the danger of being handily undermined. The good part is that a considerable lot of these flaws can be resolved just by ensuring that there are no product segments with known bugs. There are various ways in Kubernetes by which you can fix these product flaws, for example:

  • Automating Security Vulnerability Scanning of Container Images – Containers may contain outdated software libraries with known vulnerabilities, which can be a danger, as new vulnerabilities are released each day. So the most secure way is to automate container deployment where containers are constantly evaluated for threats and attacks. There are many tools available for automating container deployments; for example, Conjure-Up can deploy a distribution of Kubernetes over many cloud providers utilizing simple commands. It also helps embed image scanning into the pipeline, which scans container images for vulnerabilities by automating security into registries of your choice.
  • Make sure Environment is updated with most recent Security Updates. Once vulnerabilities are found in running containers, you should consistently update the source container image and redeploy the containers in pods. Updating and reinstalling pods is amazingly simple in Kubernetes due to its rolling updates feature, which permits the running of an application while it is being updated to the most recent version.
  • Only Using Authorized Distribution Images - Guarantee that container images that are pulled from docker hub are docker certified and adhering to the rules of organization strategy. Downloading and running uncertified docker images are risky. It is equal to download software from unauthorized sources. Utilize private libraries to store your container images. This by itself limits the odds of vulnerabilities by lessening the number of potential container images that can be used in the pipeline.

4. Limit access to users utilizing RBAC(Role-Based Access Control)

The unpredictability of a framework running on different systems, with many interconnected microservices used by hundreds of people is a nightmare. So, to take control of the consents allowed too many users. Kubernetes has created a role-based access control (RBAC) technique. In this role-based access control(RBAC) strategy, no users have a higher number of authorizations than they require to achieve their tasks viably.

RBAC does that by utilizing an API protocol that helps driving authorization choices through the Kubernetes API. As of Kubernetes version 1.8, RBAC model is steady and is inbuilt within the rbac.authorization.k8s.io/v1 API.

The command for Enabling RBAC in Kubernetes. More on this here.

--authorization-mode=RBAC

5. Limit Cluster Traffic using Transport Layer Security(TLS)

Communication between services in the cluster should be taken care of by utilizing the TLS security protocol on each deployment pipeline level since it scrambles all the traffic going between pods. Pods accept traffic from numerous sources, but when you set a particular network security protocol on the units. Pods dismiss all the connections which are not approved by that network policy. They are constrained to what is permitted by a group of numerous network security protocols.

Earlier it was a complex task to configure TLS during the deployment of pods manually, but advances in service mesh technologies have produced tools like LinkerD and Istio, which can enable TLS by default in Kubernetes cluster so that secure transmission can happen between pods.

Conclusion

Overall, Kubernetes provides numerous features with regard to creating a secured cluster. However, no one arrangement can be utilized all over the place, so a specific level of understanding with these features is required to improve the cluster’s security.

We suggest using ways that were featured in this blog and utilize Kubernetes setup capacities to its best to expand the security of your units/containers. We likewise recommend you follow the standards of least privilege regardless of whether the attacker figures out how to hack into the one part of the framework they despite the need to go through extra layers of security before having the option to make changes to the sensitive information.