A Field Guide To Integrating CEL in the Kubernetes Codebase
Talkat CNCF Maintainer Summit Europe 2025 · on Monday, 2025-03-31· at 13:50· Level 3 | ICC Capital Suite 10-12·
summary
CEL is compiled with google/cel-go, extended by the apiserver/cel package to add EnvSets and DeclTypes, and is already used for CRD validation (KEP 2876), validating and mutating admission policies (KEP 3962), and experimental DRA work. A demo shows CRD additionalPrinterColumns support (KEP 4595): expressions compile at CRD install, the table converter evaluates them per-resource, and features like arrays, conditional defaults and timestamp math work in the live demo.
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chapters (11)
- 0:00Welcome
- 1:07Conference agenda
- 3:38What is CEL
- 5:27CEL in Kubernetes
- 7:36How CEL works
- 10:28CEL's evolution
- 17:18CEL for printer columns
- 21:33Live demo: printer columns
- 26:55Learning CEL resources
- 28:59Closing remarks
- 30:05Q&A
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