Chaos and Order https://www.youngju.dev/blog 천천히 올바르게. AI Researcher & DevOps Engineer Youngju's tech blog. GPU/CUDA, LLM, MLOps, Kubernetes AI workloads, distributed training, and data engineering. ko fjvbn2003@gmail.com (Youngju Kim) fjvbn2003@gmail.com (Youngju Kim) Mon, 15 Jun 2026 00:00:00 GMT https://www.youngju.dev/blog/kubernetes/2026-06-15-kubernetes-controller-without-crd.en Controllers Without CRDs — Patterns for Automating Existing Resources https://www.youngju.dev/blog/kubernetes/2026-06-15-kubernetes-controller-without-crd.en Not every automation needs a CRD. A controller that watches built-in resources alone can automate internal operations like ConfigMap/Secret sync, namespace bootstrap, and node labeling. We cover code that implements this with controller-runtime without a CRD, the distinction between an Operator and a simple controller, admission webhook policy, and pitfalls like permissions and loops. Mon, 15 Jun 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) kubernetescontrollercontroller-runtimeautomationclient-goplatform-engineering https://www.youngju.dev/blog/kubernetes/2026-06-15-kubernetes-controller-without-crd.ja CRD なしのコントローラ — 既存リソースを自動化するパターン https://www.youngju.dev/blog/kubernetes/2026-06-15-kubernetes-controller-without-crd.ja すべての自動化に CRD が必要なわけではありません。ビルトインリソースを watch するコントローラだけで、ConfigMap/Secret 同期、ネームスペースのブートストラップ、ノードラベリングといった社内運用を自動化できます。controller-runtime で CRD なしに実装するコード、Operator と単純コントローラの区別、admission webhook のポリシー、そして権限やループといった落とし穴を扱います。 Mon, 15 Jun 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) kubernetescontrollercontroller-runtimeautomationclient-goplatform-engineering https://www.youngju.dev/blog/kubernetes/2026-06-15-kubernetes-controller-without-crd CRD 없는 컨트롤러 — 기존 리소스를 자동화하는 패턴 https://www.youngju.dev/blog/kubernetes/2026-06-15-kubernetes-controller-without-crd 모든 자동화에 CRD가 필요한 것은 아닙니다. 빌트인 리소스를 watch하는 컨트롤러만으로 ConfigMap/Secret 동기화, 네임스페이스 부트스트랩, 노드 라벨링 같은 사내 운영을 자동화할 수 있습니다. controller-runtime로 CRD 없이 구현하는 코드, Operator와 단순 컨트롤러의 구분, admission webhook 정책, 그리고 권한과 루프 같은 함정을 다룹니다. Mon, 15 Jun 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) kubernetescontrollercontroller-runtimeautomationclient-goplatform-engineering