Amazon EKS Security: A Practical Guide

Amazon Elastic Kubernetes Service (EKS) is a fully managed container orchestration service offered by Amazon Web Services (AWS). Amazon EKS allows developers to deploy, manage and scale containerized applications using Kubernetes, a popular open source platform.

Kubernetes is an orchestration tool that automates the deployment, scaling and management of containerized applications. With Amazon EKS, you can use Kubernetes on AWS without the need to install, operate or maintain your own Kubernetes control plane or nodes. This means that you can focus on building applications while AWS takes care of the underlying infrastructure.

Amazon EKS provides automatic updates, self-healing and scalability, which significantly reduce operational overhead. It also integrates with other AWS services, such as AWS Fargate, Amazon RDS and Amazon S3, providing developers a secure environment to run their applications.

Importance of Security in Kubernetes Environments

As with any cloud-based environment, security is of paramount importance in Kubernetes. Containers and microservices have revolutionized how applications are developed and deployed, but they also present new security challenges that must be addressed.

In a Kubernetes environment, applications are broken down into multiple, smaller components (microservices) that are packaged into containers. These containers are then orchestrated by Kubernetes. Each of these components – the applications, the containers and the orchestrator – is a potential attack surface that needs to be secured. A successful attack on any one of these components can lead to data breaches, service disruptions and other serious consequences.

Furthermore, Kubernetes environments are dynamic and complex, with containers constantly being created, destroyed and moved around. This makes security even more challenging as traditional, static security measures are often inadequate. Instead, security in Kubernetes environments requires a dynamic, holistic approach that covers the entire application life cycle, from development to deployment to runtime.

What Should You Secure in AWS EKS?

Cluster Configuration

Cluster configuration includes settings such as networking and authentication and authorization mechanisms. Misconfigurations in any of these settings can expose your cluster to attacks.

For instance, you should configure your network plugin to enforce network policies that limit communication between pods to only what is necessary. As for authentication and authorization, you should leverage AWS’s Identity and Access Management (IAM) service to control who can access your cluster and what they can do.

Worker Nodes

Worker nodes are the Amazon machine instances where your containers run. Securing these nodes is as important as securing the containers themselves. This involves ensuring that the host operating system is secure, that unnecessary software is removed, and that security patches are applied regularly. Application mapping solutions can help you identify what software is installed on your nodes and the dependencies between them.

Additionally, you should limit the permissions of the worker nodes. By default, worker nodes have the ability to perform any action on any resource in the cluster. This is a significant security risk, as a compromised node can lead to a compromised cluster. To mitigate this risk, you should use the principle of least privilege and only grant nodes the permissions they need to perform their tasks.

Secrets Management

Secrets, such as database passwords, API keys and TLS certificates, are often needed for applications to function correctly. In a Kubernetes environment, these secrets are stored in etcd, a key-value store used by Kubernetes for all its persistent storage needs.

Securing these secrets is critical as they can provide attackers with access to sensitive resources. You should encrypt secrets at rest (i.e., when they are stored in etcd) and in transit (i.e., when they are being sent over the network). You should also control who can access these secrets using Kubernetes’s role-based access control (RBAC) feature.

Ingress and Egress Controls

Ingress and egress controls regulate how traffic enters and exits your cluster. In Kubernetes, these controls are implemented using network policies.

Network policies are a powerful tool for securing your cluster, allowing you to define which pods can communicate with each other and with other network endpoints. By default, all pods in a Kubernetes cluster can communicate with each other, which is a potential security risk. With network policies, you can restrict this communication to only what is necessary, reducing your attack surface.

Pod Security

Pods are the smallest deployable units in a Kubernetes cluster. Each pod contains one or more containers that share storage and network resources.

Securing pods involves several measures. First, you should restrict what containers can do within a pod using security contexts. For example, you can prevent containers from running as root or from accessing the host filesystem. Second, you should ensure that pods are isolated from each other as much as possible. This can be achieved using namespaces, which provide a way to divide cluster resources between multiple users or teams.

Container Images

Finally, you should secure your container images. Container images are the basis for containers and contain the application code and its dependencies.

Container images can be a source of vulnerabilities if they are not properly secured. For instance, images can contain outdated or insecure software, or they can be tampered with by attackers. To secure your images, you should use trusted sources, regularly scan your images for vulnerabilities and sign your images to ensure their integrity.

Amazon EKS Security Best Practices

Restrict Access to the Kubernetes API and Use PrivateLink

The first step to securing your Amazon EKS environment is to restrict access to the Kubernetes API. By limiting access to the API, you ensure that only authorized personnel can interact with your clusters.

Using AWS PrivateLink for private cluster endpoint access further enhances the security posture. AWS PrivateLink ensures that your traffic is not exposed to the public internet and stays within your VPC. This eliminates the risks associated with data leaks, unauthorized access, and potential attacks.

Moreover, AWS PrivateLink simplifies security management by providing fine-grained access control to services running on AWS. This allows you to enforce strict security policies and ensure that only legitimate requests are processed by your clusters.

Regularly Update EKS Clusters and Worker Nodes

Like any other technology, Kubernetes clusters and worker nodes are also susceptible to vulnerabilities. These vulnerabilities can be exploited by cybercriminals to gain unauthorized access, disrupt services or compromise the entire system.

To mitigate these risks, it is highly recommended to regularly update your EKS clusters and worker nodes to the latest secure versions. This ensures that you are not running outdated versions that can be easily compromised. 

Note that while EKS handles upgrades automatically, you still need to manually request an upgrade (it won’t happen on its own), and you need to make sure your configurations and workloads are compatible with the new version.

Use CloudOps Practices for Continuous Security Management

CloudOps, or cloud operations, plays a crucial role in maintaining the security and efficiency of Amazon EKS environments. This approach involves the continuous management, monitoring and optimization of cloud-based services and infrastructure.

Implementing automated security policies and compliance checks is vital. These policies ensure that your EKS environment adheres to the necessary security standards and regulations. Automation in CloudOps helps in continuously enforcing these policies, reducing the likelihood of human error and ensuring compliance even as your environment scales.

Disaster recovery and backup strategies are also a core part of CloudOps practices. Regularly backing up your EKS environment and having a well-planned disaster recovery strategy ensures minimal data loss and downtime in the event of a security breach or system failure. This resilience planning is essential for maintaining service continuity and safeguarding against data loss.

Use AWS Secrets Manager or AWS KMS

Storing and managing secrets is a critical aspect of Amazon EKS security. Secrets include API keys, passwords, certificates and other sensitive data.

AWS Secrets Manager and AWS Key Management Service (KMS) provide robust solutions for storing and managing secrets. These services ensure that your secrets are securely stored and are only accessible to authorized personnel.

Moreover, these services also provide automated rotation of secrets. This ensures that even if a secret gets compromised, the impact is minimized as the secret is regularly changed.

Use Amazon CloudWatch Logs and AWS CloudTrail for Monitoring

Monitoring user activities and API usage is a critical part of Amazon EKS security. It helps identify potential security threats, detect unusual activities and respond to security incidents.

Amazon CloudWatch Logs and AWS CloudTrail are powerful tools that provide comprehensive logging and monitoring capabilities. They provide real-time insights into your EKS environment, helping you stay on top of your security game.

Moreover, these tools also support automation. This means you can set up alerts and notifications for specific events, ensuring that you are immediately notified in case of a security incident.

Use Threat Detection Services Like Amazon GuardDuty

Continuous security monitoring and threat detection are critical for maintaining Amazon EKS security. This involves continuously monitoring your EKS environment for potential threats and responding to them in real-time.

Amazon GuardDuty is a threat detection service that provides continuous security monitoring. It uses machine learning, anomaly detection and integrated threat intelligence to identify and prioritize potential threats.

Integrating your EKS environment with Amazon GuardDuty ensures that you are always aware of your environment’s security status. This allows you to quickly respond to threats and minimize their impact.

Use Amazon ECR Image Scanning to Detect Vulnerabilities

Before deploying any code or application in your EKS environment, it is crucial to scan it for potential vulnerabilities. This can help you identify and fix vulnerabilities before they can be exploited.

Amazon ECR image scanning is a tool that allows you to scan your Docker images for known vulnerabilities. It uses the Common Vulnerabilities and Exposures (CVEs) database to identify vulnerabilities.

By using Amazon ECR image scanning, you can ensure that your applications are secure before they are deployed. This not only enhances your Amazon EKS security but also helps maintain compliance with security standards.

In conclusion, Amazon EKS security requires a comprehensive understanding and meticulous implementation. By following the best practices outlined in this article, you can significantly enhance the security of your Amazon EKS environment. Remember, security is not a one-time task but a continuous process. 

Gilad David Mayaan

Gilad David Maayan is a technology writer who has worked with over 150 technology companies including SAP, Samsung NEXT, NetApp and Imperva, producing technical and thought leadership content that elucidates technical solutions for developers and IT leadership.

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