Introducing Node Readiness Controller

Introducing Node Readiness Controller Why the Node Readiness Controller? Core concepts and features Flexible enforcement modes Condition reporting Operational safety with dry run Example: CNI bootstrapping Getting involved In the standard Kubernetes model, a node’s suitability for workloads hinges on a single binary "Ready" condition. However, in modern Kubernetes environments, nodes require complex infrastructure dependencies—such as network agents, storage drivers, GPU firmware, or custom health checks—to be fully operational before they can reliably host pods. Today, on behalf of the Kubernetes project, I am announcing the Node Readiness Controller. This project introduces a declarative system for managing node taints, extending the readiness guardrails during node bootstrapping beyond standard conditions. By dynamically managing taints based on custom health signals, the controller ensures that workloads are only placed on nodes that met all infrastructure-specific requirements. Core Kubernetes Node "Ready" status is often insufficient for clusters with sophisticated bootstrapping requirements. Operators frequently struggle to ensure that specific DaemonSets or local services are healthy before a node enters the scheduling pool. The Node Readiness Controller fills this gap by allowing operators to define custom scheduling gates tailored to specific node groups. This enables you to enforce distinct readiness requirements across heterogeneous clusters, ensuring for example, that GPU equipped nodes only accept pods once specialized drivers are verified, while general purpose nodes follow a standard path. It provides three primary advantages: Custom Readiness Definitions : Define what ready means for your specific platform. Automated Taint Management : The controller automatically applies or removes node taints based on condition status, preventing pods from landing on unready infrastructure. Declarative Node Bootstrapping : Manage multi-step node initialization reliably, with a clear observability into the bootstrapping process.