Aviatrix Blog 
In my previous blog post, I explored the Aviatrix Kubernetes Firewall Architecture, discussing how it provides scalable, policy-driven network security for multi-cluster and hybrid Kubernetes environments. This post takes it further by demonstrating the practical implementation that makes this a comprehensive, multi-layered solution, specific use cases and step-by-step guidance to deploy the Aviatrix Kubernetes Firewall using YAML configurations and Terraform automation.
What You’ll Learn:
You’ll get an under-the-hood view of how the Aviatrix Kubernetes Firewall enables Zero Trust security, network segmentation, and multi-tenancy enforcement in your Kubernetes environment, empowering your organization to scale securely.
Addressing Common Challenges in Large-Scale Kubernetes Deployments
The Aviatrix Kubernetes Firewall is designed to address common challenges faced in large-scale Kubernetes deployments by:
- Securing multi-tenant environments where multiple teams work within the same Kubernetes cluster, one of the biggest concerns for networking teams. Ensuring clear separation between production and non-production workloads is critical to maintaining security and compliance.
- Controlling outbound internet access from pods and clusters while enabling approved services like monitoring and logging tools to function correctly.
- Secure inter-cluster communication, especially in multicloud or hybrid deployments.
- Scaling with growing workloads while maintaining clear policy enforcement.
- Addressing IP exhaustion and overlap-related issues.
Customize Your Deployment Model: Cluster as a Service vs Namespace as a Service
Most customers tend to deploy Kubernetes applications in one of two deployment models: Cluster as a Service (CLaaS) or Namespace as a Service (NSaaS) or a combination of both as needed. CLaaS provides the isolation needed for mission-critical applications, while NSaaS provides better utilization of the cluster resources. The Aviatrix Kubernetes Firewall helps in both deployment models to provide security, governance, and tenant isolation.
Cluster as a Service with the Aviatrix Kubernetes Firewall
Namespace-as-a-Service with the Aviatrix Kubernetes Firewall
Customer Journey: Implementing the Aviatrix Kubernetes Firewall
Implementing the Aviatrix Kubernetes Firewall requires a phased approach:
- Kubernetes Firewall supports multiple sections that can be operated by different personas like Security admins, Platform admins, DevOps, DevSecOps as well as developers. Each persona can independently program their section for layered security.
- The security admins can define global as well as threat and geoblocking rules.
- Next, platform admins need to define security guardrails using Terraform or UI, ensuring that all Kubernetes workloads operate as part of CLaaS or NSaaS.
- Application owners or DevSecOps team can program Pod-based rules through Custom Resources (CR).
- Once firewall rules are in place, define policies that restrict inter-cluster communication, enforce namespace isolation, and regulate outbound traffic.
- Finally, set up observability and logging to monitor firewall rule enforcement and troubleshoot potential connectivity issues.
Overall Firewall Rule Table
Simplify and Streamline: Automating the Aviatrix Kubernetes Firewall Deployment with Terraform and Kubernetes Custom Resources
Instead of manually applying firewall policies, a time-consuming process that could cause human errors, organizations can easily automate deployment using Terraform and Kubernetes custom resource definitions (CRDs). Terraform enables infrastructure-as-code, allowing teams to define firewall rules in a consistent, repeatable manner.
To enable Kubernetes developers, DevOps and DevSecOps to automate Firewall policy implementation for faster developer velocity Aviatrix provides Custom Resource Definitions (CRDs) that extend Kubernetes to support advanced security configurations.
Step 1: Define Kubernetes Provider in Terraform
Step 2: Deployment of Aviatrix CRD in the clusters
Defining Firewall Rules for Kubernetes: A Step-by-Step Approach
The following section provides a step-by-step definition of how to secure your Kubernetes environments.
Step 1: Defining Global, Threat, and Geoblocking Rules
Persona: Security admin
The first step is for Security admins to define and orchestrate the Global policies for the environment that the Kubernetes clusters are being deployed. These can be implemented as part of the Global section as well as segregated into Pre-rules, global and threat sections. For multi-geo or multi-region deployments, geoblocking sections can be used for better rule management.
Step 2: Define Security Guardrails as Org policies
Persona: Platform security team
Before delegating the Kubernetes deployments (CLaaS or NSaaS) to developers or DevOps teams, the platform team must establish clear security guardrails. These guardrails ensure that Kubernetes clusters operate within a well-defined security posture. For example, organizations may choose to restrict communication between production and non-production environments, enforce bandwidth limitations, or allow only specific workloads to communicate with external services. By defining these policies early, teams can avoid misconfigurations and security loopholes later in the deployment process.
An example under these guardrails: workloads on a Production cluster should not be able to communicate with workloads in a Dev cluster and vice versa. You can implement this policy by denying all traffic between such clusters, between namespaces or can be segregated using tags. The following three images show how you can segregate production and non-production workloads based on clusters, namespaces, or tags.
Production and non-production workload segregation using clusters (CLaaS)
Production and non-production workload segregation using Namespaces (NSaaS)
Production and non-production workload segregation using tags (prod and nonprod)
Step 3: Apply Cluster-Based Egress Policies
Persona: Platform security team
With the governance rules in place, platform admins can implement common egress security rules for the cluster. As an example, platform admins can define that Kubernetes nodes can only reach Datadog service and nowhere else as follows:
Deployment of cluster-based egress policies
Step 4: Apply Pod and Service-Based Network Segmentation Policies
Persona: Developers or DevSecOps
With the CRDs deployed, developers and DevSecOps teams can define network segmentation policies that control how workloads communicate within a Kubernetes cluster and across Pods and services. These policies help enforce Zero Trust security by blocking unnecessary communication between workloads while allowing essential services to interact.
For example, developers can allow access from one of their pods to another pod depending on the application architecture without using a service or load balancers. It can be defined as follows:
Enable Pod-to-Pod communication through Aviatrix CRDs
Step 5: Secure Egress Traffic for Pods
Persona: DevSecOps
One of the most critical aspects of Kubernetes security is controlling outbound (egress) traffic. By default, Kubernetes pods can reach the public internet, which can expose workloads to security threats. The Aviatrix Kubernetes Firewall allows organizations to define egress policies that limit outbound traffic to approved services while blocking all other external connections. The DevSecOps and development teams can use Aviatrix CRD and write egress rules to access external services like S3 buckets, specific URLs, etc as follows:
Enable access to other services like S3 buckets through Aviatrix CRDs
Finalizing the Aviatrix Kubernetes Firewall Deployment
The Aviatrix Kubernetes Firewall ensures that your Kubernetes environments are secure, scalable, and compliant with enterprise security policies. This solution simplifies network segmentation, egress security, and inter-cluster communication, helping platform teams enforce Zero Trust principles while enabling application teams to deploy workloads with confidence and increased velocity.
By leveraging Terraform automation and using Kubernetes custom resources, you can manage security policies at scale, reducing the risk of misconfiguration and ensuring consistency across deployments.
- Learn how the Aviatrix Kubernetes Firewall secures and scales clusters.
- Explore three reasons to use multicloud Kubernetes networking to secure and scale clusters.