The Everything Feed - All Packet Pushers Pods HN806: Let’s Get NUTS!
Nov 21, 2025
Urs Bauman, a network automation practitioner and maintainer of the open-source Network Unit Testing System (NUTS), teams up with Marco Martinez, a Swisscom architect focused on network automation. They dive into the essence of unit testing for networks, emphasizing small, verifiable checks and the importance of pre- and post-change testing workflows. The duo introduces NUTS as a versatile testing tool leveraging YAML and pytest, making automation accessible. They also discuss community contributions, digital twins, and the seamless generation of YAML tests from source-of-truth.
AI Snips
Chapters
Transcript
Episode notes
Unit Tests Target Small Network Properties
- A network unit test checks the smallest meaningful property you can verify, like interface state or BGP neighbor status.
- Testing small, composable pieces helps catch issues before they become system-level failures.
Use Pre- and Post-Change Tests
- Run pre-tests to capture the network state before making changes so you can tell if a problem predates your change.
- Run post-tests after the change and compare results to ensure you didn't introduce regressions.
Write Minimal YAML Tests, Reuse Logic
- Use Nuts' YAML-driven, opinionated tests to define only the minimal input needed for a check.
- Reuse predefined test logic to avoid rewriting common checks across devices.