Add also-notify support for BIND domains.conf generation

Extend catz.yaml config with a bind-conf section mapping catalog names
to also-notify IP lists. Zones in catalogs with also-notify configured
get an also-notify directive in the generated domains.conf. IPs are
deduplicated and sorted when a zone belongs to multiple catalogs.

bindconf.go

@@ -10,7 +10,8 @@ import (
 // generateBindConf produces a BIND domains.conf from all zone entries.
 // Zones are sorted alphabetically. Each zone block uses 8-space indentation.
 // DNSSEC zones get dnssec-policy and inline-signing directives on the file line.
-func generateBindConf(entries []ZoneEntry) string {
+// Zones in catalogs with also-notify configured get an also-notify directive.
+func generateBindConf(entries []ZoneEntry, cfg *Config) string {
 	sorted := make([]ZoneEntry, len(entries))
 	copy(sorted, entries)
 	sort.Slice(sorted, func(i, j int) bool {
@@ -38,16 +39,48 @@ func generateBindConf(entries []ZoneEntry) string {
 			fileLine += " dnssec-policy standard; inline-signing yes;"
 		}
 		b.WriteString(fileLine + "\n")
+
+		// Collect also-notify IPs from all catalogs this zone belongs to
+		ips := alsoNotifyIPs(entry.Catalogs, cfg)
+		if len(ips) > 0 {
+			b.WriteString("        also-notify {")
+			for _, ip := range ips {
+				fmt.Fprintf(&b, " %s;", ip)
+			}
+			b.WriteString(" };\n")
+		}
+
 		b.WriteString("};\n")
 	}
 
 	return b.String()
 }
 
+// alsoNotifyIPs returns the deduplicated, sorted list of also-notify IPs
+// for a zone based on its catalog memberships.
+func alsoNotifyIPs(catalogs []string, cfg *Config) []string {
+	if len(cfg.BindConf.AlsoNotify) == 0 {
+		return nil
+	}
+
+	seen := make(map[string]bool)
+	var ips []string
+	for _, catName := range catalogs {
+		for _, ip := range cfg.BindConf.AlsoNotify[catName] {
+			if !seen[ip] {
+				seen[ip] = true
+				ips = append(ips, ip)
+			}
+		}
+	}
+	sort.Strings(ips)
+	return ips
+}
+
 // writeBindConf writes the BIND config to path.
 // Zones without a ZoneFile are skipped (catalog-only zones).
-func writeBindConf(path string, entries []ZoneEntry) error {
-	content := generateBindConf(entries)
+func writeBindConf(path string, entries []ZoneEntry, cfg *Config) error {
+	content := generateBindConf(entries, cfg)
 	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
 		return fmt.Errorf("writing bind config %s: %w", path, err)
 	}

bindconf_test.go

@@ -7,13 +7,15 @@ import (
 	"testing"
 )
 
+var emptyCfg = &Config{}
+
 func TestGenerateBindConf(t *testing.T) {
 	entries := []ZoneEntry{
 		{Zone: "bitcard.org.", ZoneFile: "data/misc/bitcard.org", DNSSEC: true, ZonesFile: "test", Line: 1},
 		{Zone: "askask.com.", ZoneFile: "data/ask/askask.com", ZonesFile: "test", Line: 2},
 	}
 
-	got := generateBindConf(entries)
+	got := generateBindConf(entries, emptyCfg)
 
 	// Header
 	assertContains(t, got, "# THIS FILE IS GENERATED BY catalog-zone-gen")
@@ -44,7 +46,7 @@ func TestGenerateBindConf(t *testing.T) {
 }
 
 func TestGenerateBindConfEmpty(t *testing.T) {
-	got := generateBindConf(nil)
+	got := generateBindConf(nil, emptyCfg)
 	// Should just have the header
 	lines := splitLines(got)
 	if len(lines) != 3 {
@@ -57,7 +59,7 @@ func TestGenerateBindConfNoDNSSEC(t *testing.T) {
 		{Zone: "example.com.", ZoneFile: "data/example.com", ZonesFile: "test", Line: 1},
 	}
 
-	got := generateBindConf(entries)
+	got := generateBindConf(entries, emptyCfg)
 
 	if strings.Contains(got, "dnssec-policy") {
 		t.Error("non-DNSSEC zone should not have dnssec-policy")
@@ -73,7 +75,7 @@ func TestValidateBindConf(t *testing.T) {
 			{Zone: "a.example.com.", ZoneFile: "data/a", ZonesFile: "zones.txt", Line: 1},
 			{Zone: "b.example.com.", ZoneFile: "data/b", ZonesFile: "zones.txt", Line: 2},
 		}
-		if err := writeBindConf(filepath.Join(t.TempDir(), "domains.conf"), entries); err != nil {
+		if err := writeBindConf(filepath.Join(t.TempDir(), "domains.conf"), entries, emptyCfg); err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
 	})
@@ -85,7 +87,7 @@ func TestValidateBindConf(t *testing.T) {
 		}
 		dir := t.TempDir()
 		path := filepath.Join(dir, "domains.conf")
-		if err := writeBindConf(path, entries); err != nil {
+		if err := writeBindConf(path, entries, emptyCfg); err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
 		data, err := os.ReadFile(path)
@@ -109,7 +111,7 @@ func TestWriteBindConf(t *testing.T) {
 		{Zone: "example.org.", ZoneFile: "data/example.org", DNSSEC: true, ZonesFile: "test", Line: 2},
 	}
 
-	if err := writeBindConf(path, entries); err != nil {
+	if err := writeBindConf(path, entries, emptyCfg); err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
 
@@ -132,7 +134,7 @@ func TestWriteBindConfSkipsCatalogOnlyZones(t *testing.T) {
 		{Zone: "example.com.", ZoneFile: "", ZonesFile: "zones.txt", Line: 5},
 	}
 
-	if err := writeBindConf(path, entries); err != nil {
+	if err := writeBindConf(path, entries, emptyCfg); err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
 
@@ -148,3 +150,73 @@ func TestWriteBindConfSkipsCatalogOnlyZones(t *testing.T) {
 		t.Error("zone without file= should not appear in BIND config")
 	}
 }
+
+func TestGenerateBindConfAlsoNotify(t *testing.T) {
+	cfg := &Config{
+		BindConf: BindConfConfig{
+			AlsoNotify: map[string][]string{
+				"pch": {"198.51.100.1", "198.51.100.2"},
+			},
+		},
+	}
+
+	t.Run("zone in catalog with also-notify", func(t *testing.T) {
+		entries := []ZoneEntry{
+			{Zone: "example.com.", Catalogs: []string{"pch"}, ZoneFile: "data/example.com", ZonesFile: "test", Line: 1},
+		}
+		got := generateBindConf(entries, cfg)
+		assertContains(t, got, "also-notify { 198.51.100.1; 198.51.100.2; };")
+	})
+
+	t.Run("zone in catalog without also-notify", func(t *testing.T) {
+		entries := []ZoneEntry{
+			{Zone: "example.com.", Catalogs: []string{"standard"}, ZoneFile: "data/example.com", ZonesFile: "test", Line: 1},
+		}
+		got := generateBindConf(entries, cfg)
+		if strings.Contains(got, "also-notify") {
+			t.Error("zone in catalog without also-notify config should not have also-notify")
+		}
+	})
+
+	t.Run("zone in multiple catalogs combines IPs", func(t *testing.T) {
+		cfg := &Config{
+			BindConf: BindConfConfig{
+				AlsoNotify: map[string][]string{
+					"pch":   {"198.51.100.1"},
+					"extra": {"198.51.100.2"},
+				},
+			},
+		}
+		entries := []ZoneEntry{
+			{Zone: "example.com.", Catalogs: []string{"pch", "extra"}, ZoneFile: "data/example.com", ZonesFile: "test", Line: 1},
+		}
+		got := generateBindConf(entries, cfg)
+		assertContains(t, got, "also-notify { 198.51.100.1; 198.51.100.2; };")
+	})
+
+	t.Run("duplicate IPs across catalogs are deduplicated", func(t *testing.T) {
+		cfg := &Config{
+			BindConf: BindConfConfig{
+				AlsoNotify: map[string][]string{
+					"pch":   {"198.51.100.1", "198.51.100.2"},
+					"extra": {"198.51.100.2", "198.51.100.3"},
+				},
+			},
+		}
+		entries := []ZoneEntry{
+			{Zone: "example.com.", Catalogs: []string{"pch", "extra"}, ZoneFile: "data/example.com", ZonesFile: "test", Line: 1},
+		}
+		got := generateBindConf(entries, cfg)
+		assertContains(t, got, "also-notify { 198.51.100.1; 198.51.100.2; 198.51.100.3; };")
+	})
+
+	t.Run("catalog-only zone without file skips also-notify", func(t *testing.T) {
+		entries := []ZoneEntry{
+			{Zone: "example.com.", Catalogs: []string{"pch"}, ZoneFile: "", ZonesFile: "test", Line: 1},
+		}
+		got := generateBindConf(entries, cfg)
+		if strings.Contains(got, "also-notify") {
+			t.Error("catalog-only zone should not appear in bind config at all")
+		}
+	})
+}

config.go

@@ -19,10 +19,16 @@ type SOAConfig struct {
 	Rname string `yaml:"rname"`
 }
 
+// BindConfConfig holds BIND-specific configuration for domains.conf generation.
+type BindConfConfig struct {
+	AlsoNotify map[string][]string `yaml:"also-notify"`
+}
+
 // Config holds the parsed catz.yaml configuration.
 type Config struct {
 	Catalogs map[string]CatalogConfig `yaml:"catalogs"`
 	SOA      SOAConfig                `yaml:"soa"`
+	BindConf BindConfConfig           `yaml:"bind-conf"`
 }
 
 func loadConfig(path string) (*Config, error) {
@@ -66,6 +72,13 @@ func validateConfig(cfg *Config) error {
 	if cfg.SOA.Rname == "" {
 		return fmt.Errorf("config: soa.rname is required")
 	}
+
+	for catName := range cfg.BindConf.AlsoNotify {
+		if _, ok := cfg.Catalogs[catName]; !ok {
+			return fmt.Errorf("config: bind-conf.also-notify references unknown catalog %q", catName)
+		}
+	}
+
 	return nil
 }
 

config_test.go

@@ -122,6 +122,36 @@ func TestValidateConfig(t *testing.T) {
 			t.Fatalf("unexpected error: %v", err)
 		}
 	})
+
+	t.Run("also-notify references unknown catalog", func(t *testing.T) {
+		cfg := &Config{
+			Catalogs: map[string]CatalogConfig{"cat1": {Zone: "cat.example.com."}},
+			SOA:      SOAConfig{Mname: "ns1.example.com.", Rname: "hostmaster.example.com."},
+			BindConf: BindConfConfig{
+				AlsoNotify: map[string][]string{
+					"nonexistent": {"198.51.100.1"},
+				},
+			},
+		}
+		if err := validateConfig(cfg); err == nil {
+			t.Fatal("expected error for also-notify referencing unknown catalog")
+		}
+	})
+
+	t.Run("also-notify references valid catalog", func(t *testing.T) {
+		cfg := &Config{
+			Catalogs: map[string]CatalogConfig{"cat1": {Zone: "cat.example.com."}},
+			SOA:      SOAConfig{Mname: "ns1.example.com.", Rname: "hostmaster.example.com."},
+			BindConf: BindConfConfig{
+				AlsoNotify: map[string][]string{
+					"cat1": {"198.51.100.1"},
+				},
+			},
+		}
+		if err := validateConfig(cfg); err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+	})
 }
 
 func TestLoadConfigWritePermission(t *testing.T) {

main.go

@@ -72,7 +72,7 @@ func main() {
 	}
 
 	if *bindConf != "" {
-		if err := writeBindConf(*bindConf, entries); err != nil {
+		if err := writeBindConf(*bindConf, entries, cfg); err != nil {
 			fmt.Fprintf(os.Stderr, "error: %s\n", err)
 			hasErrors = true
 		} else {