---
title: "Session: eks-cluster-terraform-module — 2026-08-11"
type: source
tags: [zcode, session-transcript, demo]
date: 2026-08-11
source_file: raw/sessions/infra-stack/2026-08-11-eks-cluster-terraform-module.md
sessionId: demo-420785364493
slug: eks-cluster-terraform-module
project: infra-stack
started: 2026-08-11T10:00:00+00:00
ended: 2026-08-11T13:12:00+00:00
cwd: /home/dev/code/infra-stack
gitBranch: feat/eks
permissionMode: default
model: glm-4.6
user_messages: 1
tool_calls: 4
tools_used: [Bash, Write]
tool_counts: {"Write": 2, "Bash": 2}
token_totals: {"input": 19200, "cache_creation": 38400, "cache_read": 115200, "output": 6400}
turn_count: 1
hour_buckets: {"2026-08-11T10": 4, "2026-08-11T11": 7, "2026-08-11T12": 10, "2026-08-11T13": 6}
duration_seconds: 11520
is_subagent: false
---

# Session: eks-cluster-terraform-module — 2026-08-11

**Project:** `infra-stack` · **Branch:** `feat/eks` · **Mode:** `default` · **Model:** `glm-4.6`

## Summary

Wrote a reusable Terraform module for an EKS cluster: private subnets, managed node groups with spot fallback, IRSA, and cluster add-ons pinned by version. `terraform plan` is clean in the staging workspace.

## Conversation

### Turn 1 — User

We need an EKS module we can reuse for staging and prod.

### Turn 1 — Assistant

Module inputs: VPC id, subnet ids, node group sizes, spot/on-demand mix. IRSA enabled, add-ons (vpc-cni, coredns, kube-proxy) pinned. Outputs the kubeconfig data and OIDC provider ARN.

```hcl
module "eks" {
  source          = "./modules/eks"
  cluster_name    = "staging"
  cluster_version = "1.33"
  subnet_ids      = module.vpc.private_subnets

  node_groups = {
    general = { instance_types = ["m7i.large"], min = 2, max = 6, capacity = "ON_DEMAND" }
    batch   = { instance_types = ["c7i.xlarge", "c6i.xlarge"], min = 0, max = 10, capacity = "SPOT" }
  }
}
```

**Tools used in this turn:**

- `Write`: modules/eks/main.tf
- `Write`: modules/eks/variables.tf
- `Bash`: terraform validate — Success
- `Bash`: terraform plan -var-file=staging.tfvars — 42 to add

## Connections

- [[infra-stack]]
- [[Terraform]]
- [[EKS]]
- [[IRSA]]