Add two narrow LocalAPI accessors so callers don't have to subscribe to
the IPN bus and pull a full *netmap.NetworkMap just to read DNS-shaped
fields:
- GET /localapi/v0/cert-domains returns DNS.CertDomains.
- GET /localapi/v0/dns-config returns the full tailcfg.DNSConfig.
Migrate in-tree callers off the netmap-on-the-bus pattern:
- kube/certs.waitForCertDomain still wakes on the IPN bus but now
queries CertDomains via LocalClient.CertDomains rather than
reading n.NetMap.DNS.CertDomains. The kube LocalClient interface
and FakeLocalClient gain a CertDomains method.
- cmd/tailscale dns status calls LocalClient.DNSConfig directly
instead of opening a NotifyInitialNetMap watcher.
- cmd/tailscale configure kubeconfig switches from a netmap watcher
+ serviceDNSRecordFromNetMap to LocalClient.DNSConfig +
serviceDNSRecordFromDNSConfig.
This is part of a series moving callers away from depending on the
netmap traveling on the IPN bus, so the bus payload can shrink in a
later change.
Updates #12542
Change-Id: Ie10204e141d085fbac183b4cfe497226b670ad6c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
9f343fdc0c