Publish DHCP clients' names in DNS

router-webui leases-dns reads Kea's leases and publishes <name>.<domain>
with reverse records in the running Unbound (router.dns.dynamicLeases).
Names the configuration publishes are never taken over; a client's name
is cut to its first label and kept inside the local domain; of two
clients the newer lease wins. The DNS page switches it on and shows what
is published and what was skipped; router-setup enables it with a domain.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AeFqV9dZrK6nipHkPfyM4F

pkgs/router-webui/dns.go

@@ -170,6 +170,32 @@ type dnsData struct {
 	Errors  FormErrors
 	Domain  string
 	Auto    []string // published without a record here
+	Dynamic bool     // router.dns.dynamicLeases
+	Dyn     *dynStatus
+}
+
+func (s Settings) dynamicLeases() bool {
+	router, _ := s["router"].(map[string]any)
+	dns, _ := router["dns"].(map[string]any)
+	return boolean(dns, false, "dynamicLeases")
+}
+
+func (s Settings) setDynamicLeases(on bool) {
+	dns := obj(obj(s, "router"), "dns")
+	if on {
+		dns["dynamicLeases"] = true
+	} else {
+		delete(dns, "dynamicLeases")
+	}
+}
+
+// dnsView is the page's data for settings s.
+func (a *app) dnsView(s Settings, records, zones []DNSRecord, errs FormErrors) dnsData {
+	d := dnsData{Records: records, Zones: zones, Errors: errs, Domain: s.domain(), Auto: s.dnsAuto(), Dynamic: s.dynamicLeases()}
+	if st, ok := readDynStatus(a.sys.leasesDNSDir()); ok {
+		d.Dyn = &st
+	}
+	return d
 }
 
 func (s Settings) dnsAuto() []string {
@@ -198,8 +224,7 @@ func (a *app) dnsPage(w http.ResponseWriter, r *http.Request, sess session) {
 		a.render(w, "dns", p)
 		return
 	}
-	p.Data = dnsData{Records: append(s.dnsRecords(), DNSRecord{}), Zones: append(s.forwardZones(), DNSRecord{}),
-		Domain: s.domain(), Auto: s.dnsAuto()}
+	p.Data = a.dnsView(s, append(s.dnsRecords(), DNSRecord{}), append(s.forwardZones(), DNSRecord{}), nil)
 	a.render(w, "dns", p)
 }
 
@@ -222,15 +247,17 @@ func (a *app) dns(w http.ResponseWriter, r *http.Request, sess session) {
 		return
 	}
 	records, zones := dnsRows(r, "rec"), dnsRows(r, "zone")
+	dynamic := r.PostFormValue("dynamic") == "on"
 	if err := s.applyDNS(records, zones); err != nil {
 		var fe FormErrors
 		errors.As(err, &fe)
 		p.Error = "Please correct the marked fields."
-		p.Data = dnsData{Records: records, Zones: zones, Errors: fe, Domain: s.domain(), Auto: s.dnsAuto()}
+		p.Data = a.dnsView(s, records, zones, fe)
 		w.WriteHeader(http.StatusUnprocessableEntity)
 		a.render(w, "dns", p)
 		return
 	}
+	s.setDynamicLeases(dynamic)
 	if err := s.save(a.sys.settingsPath()); err != nil {
 		p.Error = "Saving: " + err.Error()
 		a.render(w, "dns", p)