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GKE Cluster Configuration Reference

Detailed reference for the camaradesuk GKE cluster configuration.

Cluster Overview

Setting Value Rationale
Cluster Name camaradesuk Organization-level naming
Provider Google Kubernetes Engine (GKE) Team familiarity, GSM integration
Project camarades-net Existing GCP project
Location europe-west2-a (London) Data residency, low latency
Kubernetes Version Auto (Regular channel) Automatic updates, stable releases

Node Configuration

Setting Value Rationale
Machine Type e2-standard-2 2 vCPU, 8 GB RAM - right-sized for workload
Initial Nodes 3 Minimum for ArgoCD HA
Autoscaling 3-6 nodes Cost optimization with headroom
Disk Size 100 GB pd-standard Sufficient for container images and logs
Preemptible No (currently) Reliability during migration

Feature Configuration

Workload Identity

Enabled: Yes Pool: camarades-net.svc.id.goog

Purpose: Secure authentication for pods to access Google Cloud services (e.g., Secret Manager).

Usage: External Secrets Operator uses Workload Identity to fetch secrets from Google Secret Manager.

Vertical Pod Autoscaling (VPA)

Enabled: Yes

Purpose: Automatically right-size pod resource requests based on actual usage.

Status: Enabled at cluster level, VPA objects created per-service.

Shielded Nodes

Enabled: Yes Secure Boot: Enabled Integrity Monitoring: Enabled

Purpose: Enhanced node security with verified boot and runtime integrity.

Auto-Upgrade and Auto-Repair

Both Enabled: Yes Maintenance Window: Daily at 03:00 UTC

Purpose: Automatic security patches and node health management.

Network Configuration

Setting Value
Network default
Subnetwork default
IP Allocation Automatic
Cluster CIDR Auto-assigned
Services CIDR Auto-assigned

Addons

  • ✅ Horizontal Pod Autoscaling - Automatic pod scaling based on CPU/memory
  • ✅ HTTP Load Balancing - GKE Ingress controller
  • ✅ GCE Persistent Disk CSI Driver - Modern persistent volume driver

Cost Analysis

Estimated Monthly Cost (as of 2025-11-12):

Component Cost
GKE Control Plane $73/month
Compute (3 × e2-standard-2) $162/month
Storage & Networking ~$25/month
Total ~$260/month

Cost Optimization Opportunities: - Preemptible nodes: ~$100/month savings (40% reduction) - Right-sized workloads: Autoscaler may scale down to 3 nodes permanently - Sustained use discounts: Automatic 20-30% discount

Comparison to Legacy Cluster

Aspect Legacy (camarades) New (camaradesuk)
Nodes 10 nodes 3-6 nodes (autoscaling)
Machine Types Mixed (c2, e2) e2-standard-2 (uniform)
Preemptible 70% preemptible 0% (future: mixed)
Workloads 168 pods (Jenkins X) ~35-50 pods (GitOps)
Cost ~$435/month ~$260/month (-40%)
Management Manual (gcloud) Terraform (IaC)

Configuration Files

All configuration is defined in Terraform in the camarades-infrastructure repository:

  • main.tf - Cluster and node pool resources
  • variables.tf - Configurable values
  • outputs.tf - Cluster information exports

Modification Guide

To change cluster configuration:

  1. Edit terraform/main.tf or terraform/variables.tf
  2. Run terraform plan to review changes
  3. Run terraform apply to apply changes
  4. Update this document to reflect the change

See Terraform Guide for detailed instructions.