## Why
Vault's kubernetes secret engine will mint scoped tokens for a static \`agent-dns\` service account instead of generating cluster-wide RBAC, so agent DNS access is confined to exactly the bind namespaces. This is the GitOps half of the terraform-vault agent-dns role rework (PR unkin/terraform-vault#109). Ordering: this must sync before the Vault \`agent-dns\` creds are usable — Vault mints tokens for an SA that must already exist.
## How
- Add ServiceAccount \`agent-dns\` + ClusterRole \`agent-dns\` (definition only, no ClusterRoleBinding) in \`bind-system\`: full verbs on \`bind.unkin.net\` CRDs, get/list/watch pods/services/configmaps/events, get pods/log.
- Add RoleBinding \`agent-dns\` in each of \`bind-system\`, \`bind-internal\`, \`bind-external\`, \`externaldns\`, binding the SA to the ClusterRole in that namespace — confining all access (reads included) to those four namespaces.
Whitelist note: the platform AppProject already permits ClusterRole/ClusterRoleBinding and all four namespace destinations, so no project change is needed.
https://claude.ai/code/session_01JUoARVdmhxKQHyyyp1pxeT
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Co-authored-by: Ben Vincent <neotheo@gmail.com>
Reviewed-on: #332
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>
- Add externaldns base ArgoCD application with namespace and Vault integration
- Create externaldns overlay for au-syd1 with Helm chart configuration
- Update platform ApplicationSet to include externaldns deployment
- Configure external-dns v1.19.0 with RFC2136 provider for DNS updates
- Maintain one-to-one migration from Terraform configuration including TSIG secrets
Reviewed-on: #43
unkinben