Advanced Topics

This page covers advanced development topics including profiling and CI infrastructure.

Profiling

Golang pprof profiler can be enabled for debugging and performance analysis.

Enabling the Profiler

1. Enable profiler in operator.yaml by changing value of ENABLE_PROFILER to True
2. You can change profiler port by editing PROFILER_PORT - default is 6060
3. Deploy new code to cluster - example: make cluster-sync
4. Find nmstate-handler pod name - kubectl get pods -n nmstate
5. Create port forwarding to pod - example: kubectl port-forward pod pod_name 6060:6060 -n nmstate
6. Use go tool pprof ... to gather relevant metrics

Profiling Examples

• Open in browser http://localhost:6060/debug/pprof/
• Download memory graph go tool pprof -png http://localhost:6060/debug/pprof/heap > out.png
• Open CLI for cpu 30s sample data go tool pprof http://localhost:6060/debug/pprof/profile?seconds=30

More examples: https://golang.org/pkg/net/http/pprof/

CI Infrastructure

The kubernetes-nmstate project uses the following CI infrastructure:

• Prow - Main CI system
• Flakefinder - Flaky test detection

Code Structure Notes

• Controllers use controller-runtime reconciliation pattern
• Handler filters events to only its node using labels.SelectorFromSet
• NetworkManager compatibility: >= 1.22 for versions > 0.15.0
• The handler requires a file lock (pkg/file/lock.go) to prevent concurrent nmstatectl operations
• Profiling can be enabled via ENABLE_PROFILER env var (default port 6060)