zones: ignore machine-less zones

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

pkg/zones/scan.go

@@ -3,6 +3,8 @@ package zones
 import (
 	"io/fs"
 	"sort"
+
+	"darvaza.org/core"
 )
 
 func (m *Zones) scan(opts *ScanOptions) error {
@@ -31,22 +33,31 @@ func (m *Zones) scanDirectory(_ *ScanOptions) error {
 
 	for _, e := range entries {
 		if e.IsDir() {
-			z := &Zone{
-				zones: m,
-				Name:  e.Name(),
+			z, err := m.newZone(e.Name())
+			switch {
+			case err != nil:
+				return core.Wrap(err, e.Name())
+			case z.Machines.Len() > 0:
+				m.Zones = append(m.Zones, z)
 			}
-
-			if err := z.scan(); err != nil {
-				return err
-			}
-
-			m.Zones = append(m.Zones, z)
 		}
 	}
 
 	return nil
 }
 
+func (m *Zones) newZone(name string) (*Zone, error) {
+	z := &Zone{
+		zones: m,
+		Name:  name,
+	}
+
+	if err := z.scan(); err != nil {
+		return nil, err
+	}
+	return z, nil
+}
+
 func (m *Zones) scanMachines(opts *ScanOptions) error {
 	var err error
 	m.ForEachMachine(func(p *Machine) bool {