OpenCost — Kubernetes Cost Tracking

OpenCost (CNCF incubating) breaks down your Kubernetes cluster costs by namespace, deployment, pod, and custom labels. See exactly which teams and services are consuming your cloud budget.

Helm Installation

# Add the OpenCost Helm repo
helm repo add opencost https://opencost.github.io/opencost-helm-chart
helm repo update

# Install OpenCost in the opencost namespace
helm install opencost opencost/opencost \
  --namespace opencost \
  --create-namespace \
  --set opencost.exporter.cloudProviderApiKey="AIzaSyD-9tSrke72..." \  # GCP only
  --set opencost.prometheus.internal.enabled=true

# For AWS, set the cluster region and node pricing
helm install opencost opencost/opencost \
  --namespace opencost \
  --create-namespace \
  --set opencost.exporter.aws.region=us-east-1 \
  --set opencost.prometheus.internal.enabled=true

# Access the UI (port-forward)
kubectl port-forward -n opencost svc/opencost 9090:9090 9003:9003 &
open http://localhost:9090

REST API — Query Namespace Costs

# Cost by namespace, last 7 days, accumulated total
curl "http://localhost:9090/model/allocation?window=7d&aggregate=namespace&accumulate=true" \
  | jq '.data[0] | to_entries | map({namespace: .key, cost: .value.totalCost}) | sort_by(-.cost)'

# Cost by deployment in a specific namespace
curl "http://localhost:9090/model/allocation?window=30d&aggregate=deployment&accumulate=true&filter=namespace:production" \
  | jq '.data[0] | to_entries[] | {deployment: .key, cost: .value.totalCost}'

# Cost by team label (requires pods to have label app.kubernetes.io/team)
curl "http://localhost:9090/model/allocation?window=7d&aggregate=label:team&accumulate=true"

# Daily cost breakdown for a namespace (accumulate=false)
curl "http://localhost:9090/model/allocation?window=14d&aggregate=namespace&accumulate=false&filter=namespace:staging" \
  | jq '.data[] | {date: .window.start, cost: .["staging"].totalCost}'

# Assets API — raw node/disk costs
curl "http://localhost:9090/model/assets?window=7d&aggregate=type&accumulate=true"

Python Script — Weekly Cost Report

import requests
import json

OPENCOST_URL = "http://localhost:9090"

def get_namespace_costs(window="7d"):
    resp = requests.get(f"{OPENCOST_URL}/model/allocation", params={
        "window": window,
        "aggregate": "namespace",
        "accumulate": "true"
    })
    data = resp.json()["data"][0]
    costs = [
        {"namespace": k, "cost": round(v["totalCost"], 2), "cpu": round(v["cpuCost"], 2), "memory": round(v["ramCost"], 2)}
        for k, v in data.items()
    ]
    return sorted(costs, key=lambda x: x["cost"], reverse=True)

def print_report():
    costs = get_namespace_costs("30d")
    total = sum(c["cost"] for c in costs)
    print(f"\\n=== Kubernetes Cost Report (Last 30 Days) ===")
    print(f"Total cluster cost: ${total:.2f}\\n")
    print(f"{'Namespace':<30} {'Total':>10} {'CPU':>10} {'Memory':>10}")
    print("-" * 65)
    for c in costs[:15]:
        print(f"{c['namespace']:<30} ${c['cost']:>9.2f} ${c['cpu']:>9.2f} ${c['memory']:>9.2f}")

print_report()

OpenCost vs Kubecost Comparison