Disable zones instead of deleting them

A disabled zone stays in Jarl with its records, options and history,
still editable, but named doesn't load it; enabling it serves it as it is
then. Signed zones, and zones another view shares, can't be disabled.
jarl zone disable|enable, the zone page's Disable/Enable button.
Database schema 7.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/engine/diffops.go

@@ -63,7 +63,7 @@ func DiffOps(from, to *model.State) []model.Op {
 		n := to.Zones[k]
 		s := n.SOA
 		in := ZoneInput{Name: &n.Name, ViewID: &n.ViewID, Type: &n.Type, InView: &n.InView, File: &n.File,
-			DefaultTTL: &n.DefaultTTL, SerialPolicy: &n.SerialPolicy, DNSSECPolicy: &n.DNSSECPolicy, Comment: &n.Comment}
+			DefaultTTL: &n.DefaultTTL, SerialPolicy: &n.SerialPolicy, DNSSECPolicy: &n.DNSSECPolicy, Comment: &n.Comment, Disabled: &n.Disabled}
 		if n.Type == model.ZonePrimary {
 			in.SOA = &SOAInput{MName: &s.MName, RName: &s.RName, Serial: &s.Serial, Refresh: &s.Refresh, Retry: &s.Retry, Expire: &s.Expire, Minimum: &s.Minimum}
 		}

internal/engine/engine.go

@@ -477,12 +477,12 @@ func (e *Engine) makePlan(ctx context.Context, base, work *model.State, user str
 		changedPaths[f.Path] = true
 	}
 	for _, z := range work.SortedZones() {
-		if z.Type != model.ZonePrimary {
-			continue
+		if z.Type != model.ZonePrimary || z.Disabled {
+			continue // disabled zones aren't in named: nothing to reload
 		}
 		path := pl.out.ZoneFiles[z.ID]
 		old := base.Zones[z.ID]
-		existedInNamed := old != nil && old.Type == model.ZonePrimary && baseOut.ZoneFiles[old.ID] == path
+		existedInNamed := old != nil && old.Type == model.ZonePrimary && !old.Disabled && baseOut.ZoneFiles[old.ID] == path
 		if !existedInNamed {
 			pl.newZones = true
 			pl.verify[z.ID] = z.SOA.Serial
@@ -1054,7 +1054,7 @@ func (e *Engine) Resync(ctx context.Context, p *auth.Principal, opts ApplyOption
 	pl.configChanged = true
 	pl.reloadZones = nil
 	for _, z := range work.SortedZones() {
-		if z.Type == model.ZonePrimary {
+		if z.Type == model.ZonePrimary && !z.Disabled {
 			pl.reloadZones = append(pl.reloadZones, z)
 			pl.verify[z.ID] = z.SOA.Serial
 		}

internal/engine/expand.go

@@ -145,6 +145,12 @@ func (x *expander) expand(req Request) ([]model.Op, error) {
 			if n := len(x.st.ZoneRecords(z.ID)); n > 0 {
 				verb += fmt.Sprintf(" (with its %d records)", n)
 			}
+		} else if d := zoneToggle(req, z); d != nil {
+			if *d {
+				x.warnings = append(x.warnings, disabledZoneEffect(x.st, z))
+				return []model.Op{x.versioned(req, z.Version, "disable zone "+zoneDesc(x.st, z))}, nil
+			}
+			return []model.Op{x.versioned(req, z.Version, "enable zone "+zoneDesc(x.st, z))}, nil
 		}
 		return []model.Op{x.versioned(req, z.Version, "zone "+verb+" "+zoneDesc(x.st, z))}, nil
 	case OpRecordCreate:
@@ -1029,3 +1035,31 @@ func RedactOps(ops []model.Op) []model.Op {
 	}
 	return out
 }
+
+// zoneToggle returns the new disabled state when a zone update only
+// disables or enables the zone (nil otherwise).
+func zoneToggle(req Request, z *model.Zone) *bool {
+	var in ZoneInput
+	if decode(req.Data, &in) != nil || in.Disabled == nil || *in.Disabled == z.Disabled {
+		return nil
+	}
+	only := ZoneInput{Disabled: in.Disabled}
+	if string(mustJSON(in)) != string(mustJSON(only)) {
+		return nil
+	}
+	return in.Disabled
+}
+
+// disabledZoneEffect says what clients get once named no longer loads a
+// zone: in a view that offers recursion, answers from recursion (the
+// internet's version of the zone, if it has one); elsewhere, REFUSED.
+func disabledZoneEffect(st *model.State, z *model.Zone) string {
+	where := "this server"
+	if v := st.ViewName(z); v != "" {
+		where = "view " + v
+	}
+	if st.RecursionOn(z.ViewID) {
+		return fmt.Sprintf("once zone %s is disabled, clients of %s that may use recursion get its names from recursion: the internet's version of the zone, if there is one", dnsname.Display(z.Name), where)
+	}
+	return fmt.Sprintf("once zone %s is disabled, %s answers REFUSED for its names", dnsname.Display(z.Name), where)
+}

internal/engine/inputs.go

@@ -108,6 +108,8 @@ type ZoneInput struct {
 	// finished, off ("").
 	DNSSECPolicy *string `json:"dnssec_policy,omitempty"`
 	Comment      *string `json:"comment,omitempty"`
+	// Disabled keeps the zone in Jarl but out of named's configuration.
+	Disabled *bool `json:"disabled,omitempty"`
 
 	// Create only: name servers for the apex NS records (default: the
 	// configured default name servers), additional records, and a zone to

internal/engine/ops.go

@@ -240,6 +240,9 @@ func setZoneFields(st *model.State, z *model.Zone, in *ZoneInput, creating bool)
 	if in.SerialPolicy != nil {
 		z.SerialPolicy = strings.ToLower(strings.TrimSpace(*in.SerialPolicy))
 	}
+	if in.Disabled != nil {
+		z.Disabled = *in.Disabled
+	}
 	if in.DNSSECPolicy != nil {
 		p := strings.Trim(strings.TrimSpace(*in.DNSSECPolicy), `"`)
 		switch strings.ToLower(p) {

internal/engine/serial.go

@@ -101,8 +101,8 @@ func (e *Engine) guardSerials(ctx context.Context, base, work *model.State, bump
 			continue
 		}
 		old := base.Zones[z.ID]
-		if old == nil || old.Type != model.ZonePrimary || old.ViewID != z.ViewID {
-			continue // new to named: nothing loaded to compare with
+		if old == nil || old.Type != model.ZonePrimary || old.ViewID != z.ViewID || old.Disabled || z.Disabled {
+			continue // new to named (or not in it): nothing loaded to compare with
 		}
 		path := render.ZoneFilePath(work, z, e.cfg.Paths)
 		if cur, ok, _ := readFile(path); ok && string(cur) == render.ZoneFile(work, z) {

internal/engine/zonedisable_test.go

@@ -0,0 +1,81 @@
+package engine
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"jarl/internal/model"
+)
+
+func TestZoneDisable(t *testing.T) {
+	env := newEnv(t)
+	setupZone(env)
+	z := env.state().ZonesNamed("example.com")[0]
+	confPath := filepath.Join(env.dir, "etc/named.conf")
+	zonePath := filepath.Join(env.dir, "zones/_default/example.com.zone")
+
+	res := env.submit(env.admin, NewRequest(OpZoneUpdate, z.ID, ZoneInput{Disabled: model.Ptr(true)}))
+	if res.Ops[0].Summary != "disable zone example.com" || len(res.Warnings) != 1 || !strings.Contains(res.Warnings[0], "recursion") {
+		t.Errorf("disable: %q, warnings %v", res.Ops[0].Summary, res.Warnings)
+	}
+	conf, _ := os.ReadFile(confPath)
+	if strings.Contains(string(conf), "zone \"example.com\" {") || !strings.Contains(string(conf), `// zone "example.com" is disabled in Jarl`) {
+		t.Errorf("named.conf with the zone disabled:\n%s", conf)
+	}
+	// Still edited, and its file kept up to date.
+	env.submit(env.admin, rec("example.com", "www", "A", "192.0.2.10"))
+	if f, err := os.ReadFile(zonePath); err != nil || !strings.Contains(string(f), "www\t\tIN\tA\t192.0.2.10") {
+		t.Errorf("zone file while disabled: %v\n%s", err, f)
+	}
+
+	// Enabling brings it back.
+	res = env.submit(env.admin, NewRequest(OpZoneUpdate, z.ID, ZoneInput{Disabled: model.Ptr(false)}))
+	if res.Ops[0].Summary != "enable zone example.com" {
+		t.Errorf("enable: %q", res.Ops[0].Summary)
+	}
+	if conf, _ := os.ReadFile(confPath); !strings.Contains(string(conf), "zone \"example.com\" {") {
+		t.Errorf("named.conf after enabling:\n%s", conf)
+	}
+	// Reverting a disable enables the zone again.
+	res = env.submit(env.admin, NewRequest(OpZoneUpdate, z.ID, ZoneInput{Disabled: model.Ptr(true)}))
+	rev, err := env.e.Revert(env.ctx, res.ChangesetID, env.admin)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := env.e.Apply(env.ctx, rev.ID, env.admin, ApplyOptions{}); err != nil || env.state().Zones[z.ID].Disabled {
+		t.Errorf("revert of a disable: %v, disabled=%v", err, env.state().Zones[z.ID].Disabled)
+	}
+
+	// Signed zones can't be disabled.
+	env.submit(env.admin, NewRequest(OpZoneUpdate, z.ID, ZoneInput{DNSSECPolicy: model.Ptr("default")}))
+	if e := env.submitErr(env.admin, NewRequest(OpZoneUpdate, z.ID, ZoneInput{Disabled: model.Ptr(true)})); e.Kind != KindValidation || !strings.Contains(e.Message, "signed zone can't be disabled") {
+		t.Errorf("disabling a signed zone: %+v", e)
+	}
+}
+
+func TestZoneDisableInView(t *testing.T) {
+	env := newEnv(t)
+	setupZone(env)
+	env.submit(env.admin,
+		NewRequest(OpViewCreate, 0, ViewInput{Name: model.Ptr("internal"), MatchClients: &[]string{"10.0.0.0/8"}, AdoptZones: true}),
+		NewRequest(OpViewCreate, 0, ViewInput{Name: model.Ptr("external")}),
+	)
+	st := env.state()
+	ext := st.ViewByName("external")
+	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com"), ViewID: &ext.ID, Type: model.Ptr(model.ZoneInView), InView: model.Ptr("internal")}))
+	in := st.ZonesNamed("example.com")[0]
+	// The zone another view shares can't be disabled alone.
+	if e := env.submitErr(env.admin, NewRequest(OpZoneUpdate, in.ID, ZoneInput{Disabled: model.Ptr(true)})); e.Kind != KindValidation || !strings.Contains(e.Message, "is disabled, so this zone can't share it") {
+		t.Errorf("disabling a shared zone: %+v", e)
+	}
+	// Without recursion, the warning says REFUSED.
+	env.submit(env.admin, NewRequest(OpOptionCreate, 0, OptionInput{Scope: model.Ptr(model.ScopeView), ScopeID: &ext.ID, Name: model.Ptr("recursion"), Value: model.Ptr("no")}))
+	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("public.example"), ViewID: &ext.ID}))
+	pub := env.state().FindZone("public.example", ext.ID)
+	res := env.submit(env.admin, NewRequest(OpZoneUpdate, pub.ID, ZoneInput{Disabled: model.Ptr(true)}))
+	if len(res.Warnings) != 1 || !strings.Contains(res.Warnings[0], "view external answers REFUSED") {
+		t.Errorf("warnings = %v", res.Warnings)
+	}
+}