Open-Source Kubernetes Tools Every Infra Engineer Should Know

Too many tool lists feel like vendor ads. Here’s a lean 2025 stack we actually run in production clusters.

• Cost: ClusterCost — single agent, price-sheet aware, guardrails for labels/limits/budgets.
• Policy: Kyverno or Gatekeeper — enforce owner labels, ResourceQuota/LimitRange, PodSecurity, and network policy baselines.
• Debugging: k9s + stern — fast triage for pods/logs without port-forward gymnastics.
• Observability: OTEL collectors + light Prometheus — scrape essentials, export to your APM if you want; keep cardinality sane.
• Ingress: Contour or NGINX — internal + external splits, sensible timeouts, and minimal custom CRDs.
• Backup: Velero — object storage targets, tested restores, scheduled snapshots.
• Secrets: External Secrets Operator — pull from cloud secret stores; avoid baking secrets into manifests.

Keep requests/limits tight, label everything, and you have a reliable platform without SaaS sprawl.***