control runs blackbox_exporter on loopback, probing each nameserver's
public v4+v6 address for every zone: SOA (zone served) and DNSKEY (still
signed, since blackbox has no DO-bit option). Probe definitions are
shared between the exporter config and the VictoriaMetrics scrape jobs
so they can't drift. Verified live against ns1/ns2 over v4 and v6.
The control/ns1/ns2 mesh IPs and the /88 subnet were duplicated literals in
mesh-hosts.nix. clan-core's zerotier generator already writes each machine's IP
as a public var (vars/per-machine/<m>/zerotier/zerotier-ip), so read from there
and derive the subnet from zerotier-network-id. Pure refactor: the rendered
values are identical and the system derivation hash is unchanged.
control runs VictoriaMetrics (loopback) and Grafana; every machine exports
node metrics and the nameservers export Knot stats (mod-stats + knot-exporter).
Scraping and the Grafana UI ride the ZeroTier mesh only, scoped by nftables to
the mesh /88; the public side stays closed by the Hetzner cloud firewall. The
provisioned DNS dashboard includes a per-zone SOA serial table to catch
primary/secondary drift. ZeroTier ULAs are centralised in mesh-hosts.nix.
Berwn