When etcd is persisted (for certificate backup) and a cluster is
recreated, kind tries to install CNI (kindnet) fresh but the
persisted etcd already has those resources, causing 'AlreadyExists'
errors and cluster creation failure.
This fix:
- Detects etcd mount path from kind config
- Before cluster creation, clears stale CNI resources (kindnet, coredns)
- Preserves certificate and other important data
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
675ee87544