# Helm Charts

## Schema Validation

- **Always validate values against the chart schema before committing.** Run `helm show values <repo>/<chart> --version <ver>` to check the actual structure.
- Helm chart schemas change between versions — field names and nesting can differ from documentation or online examples.
- A quick `helm template` test locally catches schema errors before deployment.
- `additionalProperties: false` in chart schemas means any extra keys at the wrong nesting level cause a hard failure.

## Version Verification

- Run `helm search repo` or check upstream docs to confirm latest stable versions
- Don't rely on memory for chart versions — they go stale quickly
- Check compatibility matrices between chart version, app version, and other cluster components

## Multi-Source Applications

- ArgoCD multi-source Applications use `$ref` syntax to combine external Helm charts with Git-stored values files
- Keep values files in Git alongside the ArgoCD Application manifest

## Timeout Handling

- Under cluster pressure (many events, etcd busy), default Helm timeouts may not be enough
- Increase timeout for initial installs (e.g., 10m instead of 5m)
- `helm upgrade --install` is idempotent — retries are safe