CAST AI Install & Auth

Overview

Connect a Kubernetes cluster (EKS, GKE, AKS, or KOPS) to CAST AI for cost optimization, autoscaling, and security scanning. Covers API key generation, Helm chart installation of the CAST AI agent, and Terraform provider setup.

Prerequisites

• A running Kubernetes cluster (EKS, GKE, AKS, or KOPS)
• kubectl configured with cluster admin access
• helm v3 installed
• A CAST AI account at https://console.cast.ai

Instructions

Step 1: Generate an API Key

Log in to https://console.cast.ai and navigate to API > API Access Keys. Create a Full Access key for Terraform-managed clusters, or Read-Only for monitoring-only.

export CASTAI_API_KEY="your-api-key-here"

# Verify the key works
curl -s -H "X-API-Key: ${CASTAI_API_KEY}" \
  https://api.cast.ai/v1/kubernetes/external-clusters | jq '.items | length'

Step 2: Install the CAST AI Agent via Helm

# Add the CAST AI Helm repository
helm repo add castai-helm https://castai.github.io/helm-charts
helm repo update

# Install the read-only monitoring agent (Phase 1)
helm upgrade --install castai-agent castai-helm/castai-agent \
  -n castai-agent --create-namespace \
  --set apiKey="${CASTAI_API_KEY}" \
  --set provider="eks"  # eks | gke | aks

kubectl get pods -n castai-agent

Step 3: Enable Full Automation (Phase 2)

export CASTAI_CLUSTER_ID="your-cluster-id"

# Cluster controller -- manages node lifecycle
helm upgrade --install cluster-controller castai-helm/castai-cluster-controller \
  -n castai-agent \
  --set castai.apiKey="${CASTAI_API_KEY}" \
  --set castai.clusterID="${CASTAI_CLUSTER_ID}"

# Evictor -- consolidates underutilized nodes
helm upgrade --install castai-evictor castai-helm/castai-evictor \
  -n castai-agent \
  --set castai.apiKey="${CASTAI_API_KEY}" \
  --set castai.clusterID="${CASTAI_CLUSTER_ID}"

# Spot handler -- graceful spot instance interruption
helm upgrade --install castai-spot-handler castai-helm/castai-spot-handler \
  -n castai-agent \
  --set castai.provider="eks" \
  --set castai.clusterID="${CASTAI_CLUSTER_ID}"

Step 4: Terraform Provider (Alternative)

terraform {
  required_providers {
    castai = {
      source  = "castai/castai"
      version = "~> 7.0"
    }
  }
}

provider "castai" {
  api_token = var.castai_api_token
}

variable "castai_api_token" {
  type      = string
  sensitive = true
}

resource "castai_eks_cluster" "this" {
  account_id = data.aws_caller_identity.current.account_id
  region     = var.aws_region
  name       = var.cluster_name
}

Step 5: Verify Connection

curl -s -H "X-API-Key: ${CASTAI_API_KEY}" \
  "https://api.cast.ai/v1/kubernetes/external-clusters/${CASTAI_CLUSTER_ID}" \
  | jq '{name: .name, status: .status, agentStatus: .agentStatus}'
# => { "name": "my-cluster", "status": "ready", "agentStatus": "online" }

Error Handling

Error	Cause	Solution
401 Unauthorized	Invalid or expired API key	Regenerate at console.cast.ai > API
403 Forbidden	Key lacks permissions	Use Full Access key for write operations
Agent CrashLoopBackOff	RBAC misconfiguration	Check kubectl logs -n castai-agent
cluster not found	Wrong cluster ID	Verify ID at console.cast.ai > Clusters
Helm chart not found	Repo not added	Run helm repo add castai-helm ...

Resources

• CAST AI Getting Started
• CAST AI Helm Charts
• Terraform Provider
• API Reference

Next Steps

Proceed to castai-hello-world to query cluster savings and node status.