Karpenter on DevOps & Rock'N'Roll

Karpenter consolidation without the pager fatigue

Tue, 16 Jun 2026 00:08:30 +0000

Karpenter’s consolidation is the feature that pays for the migration. It watches your cluster, notices that the workload fits on cheaper capacity, and rearranges the nodes to match. On a fleet running mostly spot, the savings are real and continuous — when I went through the cost optimisation exercise, it was one of the few changes that measurably moved the bill.

It is also a machine that deliberately deletes your nodes, all day, forever. If your workloads aren’t ready for that, consolidation turns into a steady drip of alerts that eventually teaches everyone to ignore the alerting channel — which is a worse outcome than paying for the oversized nodes.

Node labels for Node Exporter alerts

Wed, 04 Mar 2026 00:08:30 +0000

Running a multipurpose Kubernetes cluster where production, dev and infra workloads share the same infrastructure is pretty common. In such a setup, you often want your alerting rules to be smarter: fire a critical alert when a prod node is burning CPU, but keep it informational for a dev node. To do that, you need your Prometheus metrics to carry environment context. This post shows how to thread that label all the way from a Karpenter node pool down to the Prometheus alert.

Cutting the EKS bill: what actually moved the needle

Tue, 15 Jul 2025 00:08:30 +0000

Every cost optimisation article opens with a list of twenty things you should do. Most of them save single-digit percentages and cost you a week each. This is the shorter, more honest version: the things that actually changed my EKS bill, roughly in order of return per hour of effort, and the ones that didn’t.

Context so the numbers mean something: three clusters, a few hundred pods, mixed prod and dev, one region, Karpenter-managed nodes.