CoreDNS adoption
The upstream CoreDNS chart is staged as an Argo Application with automatic sync
disabled. It preserves the kube-system/coredns Deployment selector, the
kube-dns Service name and 10.96.0.10 ClusterIP, the current image tag,
Corefile behavior, two ODROID replicas, and the existing PDB selector.
Do not enable automatic sync before reviewing the live Argo diff and proving
DNS resolution through the two existing endpoints. The chart uses different
port names and additional Pod labels/security settings, so adoption will roll
cluster DNS even though its serving port numbers remain 53/TCP and 53/UDP.
The existing system:coredns RBAC and coredns ServiceAccount remain owned by
Kubernetes bootstrap; this chart intentionally does not render replacements.
Until cutover succeeds, the historical coredns-deployment repository remains
the live direct-CD writer. Once Argo is Synced/Healthy and DNS tests pass,
retire that workflow and its kubeconfig/RBAC and archive the deployment-only
repository.