cluster: introduce Cluster.WriteStringFile()

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/cluster/cluster_file.go

@@ -1,6 +1,7 @@
 package cluster
 
 import (
+	"bytes"
 	"fmt"
 	"io"
 	"os"
@@ -40,6 +41,21 @@ func (m *Cluster) openWriter(name string, flags int, args ...any) (io.WriteClose
 	panic("unreachable")
 }
 
+// RemoveFile deletes a file from the cluster's config directory
+func (m *Cluster) RemoveFile(name string, args ...any) error {
+	if len(args) > 0 {
+		name = fmt.Sprintf(name, args...)
+	}
+
+	err := fs.Remove(m.dir, name)
+	switch {
+	case os.IsNotExist(err):
+		return nil
+	default:
+		return err
+	}
+}
+
 // ReadFile reads a file from the cluster's config directory
 func (m *Cluster) ReadFile(name string, args ...any) ([]byte, error) {
 	if len(args) > 0 {
@@ -49,6 +65,19 @@ func (m *Cluster) ReadFile(name string, args ...any) ([]byte, error) {
 	return fs.ReadFile(m.dir, name)
 }
 
+// WriteStringFile writes the given content to a file on the machine's config directory
+func (m *Cluster) WriteStringFile(value string, name string, args ...any) error {
+	f, err := m.CreateTruncFile(name, args...)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	buf := bytes.NewBufferString(value)
+	_, err = buf.WriteTo(f)
+	return err
+}
+
 // MkdirAll creates directories relative to the cluster's config directory
 func (m *Cluster) MkdirAll(name string, args ...any) error {
 	if len(args) > 0 {

pkg/cluster/machine_file.go

@@ -1,7 +1,6 @@
 package cluster
 
 import (
-	"bytes"
 	"fmt"
 	"io"
 	"os"
@@ -42,16 +41,9 @@ func (m *Machine) openWriter(name string, flags int, args ...any) (io.WriteClose
 
 // RemoveFile deletes a file from the machine's config directory
 func (m *Machine) RemoveFile(name string, args ...any) error {
-	base := m.zone.zones.dir
 	fullName := m.getFilename(name, args...)
-	err := fs.Remove(base, fullName)
 
-	switch {
-	case os.IsNotExist(err):
-		return nil
-	default:
-		return err
-	}
+	return m.zone.zones.RemoveFile(fullName)
 }
 
 // ReadFile reads a file from the machine's config directory
@@ -63,15 +55,9 @@ func (m *Machine) ReadFile(name string, args ...any) ([]byte, error) {
 
 // WriteStringFile writes the given content to a file on the machine's config directory
 func (m *Machine) WriteStringFile(value string, name string, args ...any) error {
-	f, err := m.CreateTruncFile(name, args...)
-	if err != nil {
-		return err
-	}
-	defer f.Close()
+	fullName := m.getFilename(name, args...)
 
-	buf := bytes.NewBufferString(value)
-	_, err = buf.WriteTo(f)
-	return err
+	return m.zone.zones.WriteStringFile(value, fullName)
 }
 
 // MkdirAll creates directories relative to the machine's config directory

pkg/dns/record.go

@@ -175,6 +175,16 @@ func (mgr *Manager) genRegionsSorted() []string {
 	return SortRegions(regions)
 }
 
+func (mgr *Manager) genZonesSorted() []string {
+	zones := make([]string, 0, len(mgr.zones))
+	for name := range mgr.zones {
+		zones = append(zones, name)
+	}
+
+	sort.Strings(zones)
+	return zones
+}
+
 func (mgr *Manager) genAllAddrRecords() []AddrRecord {
 	var out []AddrRecord
 

pkg/dns/write.go

@@ -14,12 +14,13 @@ func (mgr *Manager) WriteTo(w io.Writer) (int64, error) {
 	cache := make(map[string][]netip.Addr)
 
 	// zones
-	for _, z := range mgr.zones {
+	for _, zoneName := range mgr.genZonesSorted() {
+		z := mgr.zones[zoneName]
+
 		mgr.writeZoneHosts(&buf, z)
 
 		// zone alias
 		addrs := mgr.genZoneAddresses(z)
-		zoneName := z.Name
 
 		rr := AddrRecord{
 			Name: mgr.fqdn(zoneName + mgr.suffix),