IaC for Kubernetes - Provision Clusters That Are Reproducible and Auditable

Creating a Kubernetes cluster via the console or CLI is deceptively easy. eksctl create cluster gives you a running EKS cluster in 15 minutes. But that cluster is not production-ready. It has default networking (no private endpoints), default node configuration (no taints, labels, or optimized AMIs), default security (no pod security policies or network policies), and no add-ons (no ingress controller, no cert-manager, no monitoring).

Making the cluster production-ready requires configuring all of these components, and doing it manually means it is not reproducible. When you need a second cluster for staging, disaster recovery, or a new region, you are starting from scratch. With IaC, spinning up an identical cluster is a single command.

Cluster configuration also changes over time. Kubernetes versions need upgrading, node pools need resizing, add-ons need updating, and security policies need tightening. Doing these changes through IaC means they go through code review, have a plan showing the expected impact, and can be rolled back if something goes wrong. This is especially critical for version upgrades, which can break workloads if not handled carefully.

We build a Terraform (or Pulumi) module stack that provisions the complete Kubernetes environment in layers:

Networking: VPC with public and private subnets across multiple AZs, NAT gateways, VPC endpoints for ECR/S3 (to avoid NAT costs for image pulls), and security groups for cluster and node communication. The networking layer is separate from the cluster layer so changes to one do not trigger unnecessary changes to the other.

Cluster: EKS/GKE/AKS control plane with private endpoint, OIDC provider for IAM roles for service accounts (IRSA on EKS, Workload Identity on GKE), logging enabled, and the specific Kubernetes version pinned. We configure managed node groups with custom launch templates - instance types optimized for your workload, EBS-optimized storage, and max pods per node calculated correctly.

Add-ons: Installed via the Helm Terraform provider or ArgoCD after cluster creation. Core add-ons include: AWS Load Balancer Controller (or equivalent), cert-manager with Let's Encrypt, external-dns for automatic DNS management, cluster autoscaler (or Karpenter on EKS), metrics-server, and a monitoring stack (Prometheus + Grafana or Datadog agent). Each add-on is a separate Terraform resource with explicit dependencies.

Security: Pod security standards enforced via admission controllers, network policies for namespace isolation, RBAC roles mapped to your identity provider, and secrets encryption with a customer-managed KMS key. See our Kubernetes deployment service for the full security implementation.

A fully codified Kubernetes cluster ready for production workloads:

• Network layer - VPC, subnets, NAT, VPC endpoints, all managed as code
• Cluster module - EKS/GKE/AKS with private endpoint, IRSA/Workload Identity, pinned version
• Node pools - managed node groups with custom launch templates and auto-scaling
• Add-ons - ingress controller, cert-manager, external-dns, autoscaler, monitoring
• Security - pod security standards, network policies, RBAC, secrets encryption
• Multi-environment - identical clusters for dev, staging, and production from shared modules
• Upgrade path - documented procedure for Kubernetes version upgrades via Terraform
• GitOps ready - ArgoCD bootstrap for application deployment after cluster provisioning