k8s Archives - ITNotes

Kube-green: Automatically Suspend Kubernetes Workloads After Hours to Cut Dev/Staging Cloud Costs

July 20, 2026

After watching a $847/month dev cluster bill for workloads idle 65% of the time, I set up kube-green — a Kubernetes operator that suspends Deployments and StatefulSets outside working hours. Six months later, monthly costs dropped to $290 with zero operational issues.

DevOps

ExternalDNS on Kubernetes: Automatically Sync DNS Records to Cloudflare and Route53

July 13, 2026

Manually updating DNS records every time you deploy a Kubernetes service does not scale. ExternalDNS watches your Ingress and LoadBalancer resources and automatically keeps Cloudflare or Route53 in sync — no human intervention needed. This guide walks through installation, configuration for both providers, and how to verify and monitor the setup in production.

DevOps

Managing Kubernetes Cluster Lifecycle Across Environments with Cluster API (CAPI)

July 6, 2026

Cluster API (CAPI) lets you manage the full lifecycle of Kubernetes clusters — creation, upgrades, and deletion — using declarative YAML and GitOps workflows across AWS, GCP, and bare-metal. This guide walks a junior DevOps engineer through setting up a management cluster, provisioning workload clusters, and performing rolling version upgrades without manual SSH or cloud console access.

DevOps

Istio Ambient Mesh on Kubernetes: Sidecar-Free Service Mesh for Resource Optimization

June 23, 2026

Istio Ambient Mesh eliminates per-pod sidecars by using a shared ztunnel DaemonSet for L4 mTLS and optional waypoint proxies for L7 features. This guide walks through a complete ambient mesh deployment on Kubernetes, including traffic policies, incremental migration from sidecar mode, and practical tips for cutting proxy resource overhead by up to 70%.

DevOps

Using vcluster to Create Virtual Kubernetes Clusters: Save Resources and Isolate Dev Environments

May 1, 2026

vcluster lets you run fully isolated virtual Kubernetes clusters inside a single host cluster — each with its own API server and full admin access. This guide covers how it compares to namespace isolation and separate clusters, then walks through setting one up from scratch.

DevOps

Self-Hosted GitHub Actions Runner on Kubernetes with Actions Runner Controller

April 25, 2026

Migrating GitHub Actions to self-hosted runners on Kubernetes using Actions Runner Controller (ARC) can cut CI/CD costs by 80% and eliminate queue delays. This guide walks through real production setup: Helm install, autoscaling config, Docker build strategies, and persistent caching — from someone who did it after a 2 AM build queue crisis.

Security

Kubernetes RBAC Complete Guide: Configuring Role, ClusterRole, and ServiceAccount for Least Privilege Access

April 25, 2026

Kubernetes RBAC is your first line of defense against lateral movement inside a cluster. This guide walks through creating custom Roles, ClusterRoles, and ServiceAccounts with least privilege — including verification steps and common pitfalls to avoid.

DevOps

Kubernetes Basics: Pod, Service, and Deployment Explained with Real Examples

March 7, 2026

Kubernetes solves the problem of running containers reliably at scale. This guide breaks down the three core building blocks — Pod, Service, and Deployment — with practical YAML examples and hands-on commands to deploy and manage a real application.