Cloud Security

Kubernetes Security Architecture: How To Secure It?

Kubernetes is an open-source container orchestration platform for scaling and automating container deployments. It was initially developed to manage containerized workloads in production environments and helped users define application resource boundaries. Virtualization is a Kubernetes Security Architecture practice that enables proper utilization of resources on physical servers and improves stability. Kubernetes enhances hardware performances and […]

Mansi B.

Written by Mansi B.

September 4, 2023 | 6 min read

Kubernetes is an open-source container orchestration platform for scaling and automating container deployments. It was initially developed to manage containerized workloads in production environments and helped users define application resource boundaries. Virtualization is a Kubernetes Security Architecture practice that enables proper utilization of resources on physical servers and improves stability. Kubernetes enhances hardware performances and reduces operational expenses by adding virtualization. Each virtual machine runs with its own set of components and features designated operating systems.

Kubernetes Security Architecture deployments are agile, promote continuous development and integration, and add reliability to container image building and deployments. The platform facilitates image immutability, monitors application health and performance, and streamlines OS distribution portability. However, one downside to using the Kubernetes security architecture is that it needs to be more secure by default. Users can face operational downtimes or delays when running distributed systems, and there are security issues with load balancing, configuration management, and automated rollout. 

Kubernetes Security Architecture provides flexibility and observability but does not limit applications or dictate logging, auditing, and monitoring. Malicious threat actors can exploit vulnerabilities, and supply chain risks can create issues throughout the container build cycle. Multiple components in the Kubernetes architecture need to be secured, such as worker nodes, containerized applications, and control planes. The possibility of insider threats is also high, and Kubernetes administrators with malicious intent may abuse special privileges, leak sensitive information, or cause data breaches.

This guide describes the top Kubernetes Security Architecture challenges. It covers how to set up and secure these clusters to remediate threats and prevent common misconfigurations. Let’s get started.

Table of Contents:

  1. What is Kubernetes Security Architecture?
  2. How to Secure Kubernetes Security Architecture?
    1. Use Immutable Container File Systems
    2. Build Secure Container Images
    3. Implement Kubernetes Container Hardening
    4. Network Separation and Hardening
    5. Secure Kubernetes Hosts
    6. Integrate Kubernetes Security Tools
    7. Automated Compliance
    8. Secure Access to the Kubernetes API
  3. Conclusion

What is Kubernetes Security Architecture?

The Kubernetes security architecture uses clusters, control planes, and one or more virtual machines (or physical servers) referred to as worker nodes. Worker nodes are known to host pods that house one or more containers.

Kubernetes containers are runtime environments that contain software packages and store all their dependencies. Container images have executable code and content for populating container environments.

Cluster decision-making is done by the control plane. It schedules containers to run, detects failures, and starts new pods. The critical components of the control planer are the controller manager, Kubernetes application programming interface (API) server, scheduler, and cloud controller manager.

Kubernetes worker nodes also host the Kubelet and Kube-proxy, two services allowing container orchestration. It also runs a container engine, and the CSP Kubernetes service hosts clusters. Organizations must manage various service aspects of Kubernetes, like authorization and authentication, since the default CSP configurations are insecure.

When designing the Kubernetes security architecture, organizations must understand their responsibilities and know how to maintain Kubernetes clusters.

How to Secure Kubernetes Security Architecture?

There are many ways to secure the Kubernetes security architecture. The first step is to prevent root execution by default. Users can run non-root containers or use a rootless container engine to reduce the chances of container compromise. They should also test Kubernetes applications and design them to be executed as non-root users. Integrating non-root execution into the build time enhances quality assurance and ensures Kubernetes applications run smoothly without root privileges.

It is much simpler for beginners to set up individual clusters for large-scale applications. Individuals using commercial or managed Kubernetes services can optimize resource utilization using K8s Namespaces and leverage multi-tenancy support.

The following are the best security tips for improving Kubernetes security architecture for beginners:

1. Use Immutable Container File Systems

Malicious actors are capable of gaining unrestricted execution privileges, downloading scripts, and modifying applications within containers. Users can prevent such instances by mounting secondary read/write file systems in specific directories and using immutable container file systems. 

2. Build Secure Container Images

Kubernetes container image scanning can detect vulnerabilities, prevent malicious code injections, and ensure secure deployments. Kubernetes container image scanning identifies outdated libraries, secures ports, and prevents known misconfigurations. Container image scanning is integral to the Kubernetes security architecture and can provide effective threat remediation. The Kubernetes admission controller can automatically block deployments if a container image violates the organization’s security policy. It is also essential to build and source images from trusted repositories and verify the reputation of publishers. Users should execute only digitally signed images in Kubernetes clusters.

3. Implement Kubernetes Container Hardening

Kubernetes container hardening can drastically limit the scope of attack surfaces, prevent data breaches, and protect applications. Generally speaking, there are three approaches – hypervisor-backed containerization, kernel-based solutions, and application sandboxes.

The seccomp tool can be used for audit logging and active threat detection. Many container engine solutions allow users to add a layer of isolation between the host kernel and the containerized application. Isolation boundaries enforce applications to operate within virtual sandboxes and protect host operating systems from malicious invasions. Container engines can be configured to enforce virtualization and provide better protection than traditional container isolation solutions.

4. Network Separation and Hardening

Cluster networking is used to improve communications between containers. Enforcing encryption and resource separation can prevent lateral movement in networks. Users can use network policies to isolate Kubernetes resources and secure the control plane. Encrypting traffic and sensitive data at rest (including secrets) and applying firewalling are recommended. Kubernetes namespaces can partition cluster resources across teams, users, and applications. Namespaces are not isolated by default, but users can specify authorization using RBAC and networking policies.

Pod IP addresses can change, and applications cannot depend on pods having static IP addresses. Using a Kubernetes service with the Kubernetes security architecture can solve this problem. It can assign multiple unique IP addresses to different pods and use labels for configurations. These addresses do not change while the service is still in use. Kubernetes network policies can control ingress and egress traffic. 

Two more Kubernetes security architecture recommendations for designing strong network policies are – using CNI plugins that support the NetworkPolicy API and creating guidelines for selected pods using the namespaceSelector and podSelector.

5. Secure Kubernetes Hosts

Users can deploy Kubernetes in several ways: on-premises, bare metal, and via public cloud builds. Kubernetes containers are highly portable; clients can switch between installations and migrate workloads. High degrees of customization also means that additional security vulnerabilities are introduced. One way around this is by hardening underlying hosts and installing the latest versions of operating systems. Implementing configuration management systems, patch management, firewalling, and applying relevant security measures according to the designated data center environments is essential.

Running the latest version of Kubernetes mitigates the top potential threats. It applies common bug fixes, and keeping applications up-to-date prevents unnecessary complications. Rolling updates are very popular among developers, and node pool migrations complete updates with minimal downtimes or disruptions.

6. Integrate Kubernetes Security Tools

Kubernetes security tools like Next Generation Firewalls (NGFW) and web access control gateways should be integrated with existing Kubernetes clusters and security toolsets. A great way to do this is to incorporate TCP/UDP ports and IP addresses used by workloads into perimeter security tools. It will allow users to identify and secure Kubernetes assets.

Limiting network connectivity to Kubernetes nodes and using cloud provider security groups can also align with Kubernetes security architecture management practices.

7. Automated Compliance

Optimal runtime security can be ensured by collecting data and automating the generation of compliance reports. Kubernetes compliance must adhere to the latest industry benchmarks like HIPAA, PCI-DSS, GDPR, NIST, and SOC2. It’s critical to aim for automated and continuous compliance. If a pod fails a compliance check, clusters should automatically update container images or shut it down until the issue is remediated. Users should encrypt data in transit, which can be achieved by enabling TLS encryption for Kubernetes workloads. Another great option is to enable mutual TLS, use service meshes, or use tools like PingSafe.

8. Secure Access to the Kubernetes API

The majority of Kubernetes cluster operations occur in the Kube-apiserver. The Kube control utility tool can be used to control access to the API and serves as the first line of defense. The Kubelet can assign a Quality of Service (QoS) class to pods and assist with their scheduling and consequent eviction where needed. Kubelet can help users make smarter decisions, and DevOps teams can ensure containers receive enough resources for proper functioning. All containers must have CPU and memory limits placed on them without fail.

PingSafe has a comprehensive Cloud-Native Application Protection Platform (CNAPP) tool with a built-in Kubernetes Security Posture Management (KSPM) solution. It can apply fine-grained security policies, restrict communications between workloads and third-party apps, and limit access to the API. The tool detects and mitigates advanced persistent threats using machine learning and artificial Intelligence and even comes with an Offensive Security Engine that enforces a rule-based approach to security and monitoring threats. Deploying a scalable, unified, and unique microsegmentation model for Kubernetes hosts, VMs, and containers can provide much-needed Kubernetes security across multi-cluster, multi-cloud, and hybrid deployments.

Conclusion

Enterprises are embracing the increased adoption of container orchestration platforms like Kubernetes, and there is a shift to protecting infrastructures and leveraging containerized workloads and applications. Kubernetes offers comprehensive security features and settings, but it is not secure by default and needs to be configured. Containers can be run properly, and threats must be remediated before they escalate. It starts by designing a practical Kubernetes Security Architecture. There are various tools organizations can use to get started, and many open-source solutions are available in the market. 

They are achieving continuous visibility, improving observability, and ensuring that containers run as safely and securely as possible. Kubernetes security tools can monitor the build process and uncover hidden vulnerabilities, thus helping organizations stay protected.