dns/show: sort records

v2: change Name to lower case and Type to upper case before comparing

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

pkg/dns/record.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"net/netip"
 	"sort"
+	"strings"
 	"time"
 
 	"darvaza.org/core"
@@ -38,6 +39,53 @@ func SortAddrRecords(s []AddrRecord) []AddrRecord {
 	return s
 }
 
+// SortRecords sorts a slice of [libdns.Record], by Name, Type and Value
+func SortRecords(s []libdns.Record) []libdns.Record {
+	sort.Slice(s, func(i, j int) bool {
+		return lessRecord(s[i], s[j])
+	})
+	return s
+}
+
+func lessRecord(a, b libdns.Record) bool {
+	aName := strings.ToLower(a.Name)
+	bName := strings.ToLower(b.Name)
+
+	switch {
+	case aName < bName:
+		return true
+	case aName > bName:
+		return false
+	}
+
+	aType := strings.ToUpper(a.Type)
+	bType := strings.ToUpper(b.Type)
+
+	switch {
+	case aType < bType:
+		return true
+	case aType > bType:
+		return false
+	case aType == "A", aType == "AAAA":
+		// IP Addresses
+		var aa, ba netip.Addr
+
+		switch {
+		case aa.UnmarshalText([]byte(a.Value)) != nil:
+			// bad address on a
+			return true
+		case ba.UnmarshalText([]byte(b.Value)) != nil:
+			// bad address on b
+			return false
+		default:
+			return aa.Less(ba)
+		}
+	default:
+		// text
+		return a.Value < b.Value
+	}
+}
+
 // SortRegions sorts regions. first by length those 3-character
 // or shorter, and then by length. It's mostly aimed at
 // supporting ISO-3166 order

pkg/dns/show.go

@@ -14,20 +14,25 @@ import (
 
 // Show shows current DNS entries
 func (mgr *Manager) Show(ctx context.Context, names ...string) error {
-	var buf bytes.Buffer
-
 	recs, err := mgr.GetRecords(ctx, names...)
 	if err != nil {
 		return core.Wrap(err, "GetRecords")
 	}
 
+	SortRecords(recs)
+	return writeRecords(recs, os.Stdout)
+}
+
+func writeRecords(recs []libdns.Record, w io.Writer) error {
+	var buf bytes.Buffer
+
 	for _, rr := range recs {
 		_ = fmtRecord(&buf, rr)
 		_, _ = buf.WriteRune('\n')
 	}
 	_, _ = fmt.Fprintf(&buf, "; %v records\n", len(recs))
 
-	_, err = buf.WriteTo(os.Stdout)
+	_, err := buf.WriteTo(w)
 	return err
 }