zones: adds ForEachZone iterator

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

pkg/zones/machine.go

@@ -1,7 +1,10 @@
 package zones
 
 import (
+	"fmt"
+	"io/fs"
 	"net/netip"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"sync"
@@ -56,3 +59,25 @@ func (m *Machine) FullName() string {
 
 	return m.Name
 }
+
+// ReadFile reads a file from the machine's config directory
+func (m *Machine) ReadFile(name string, args ...any) ([]byte, error) {
+	base := m.zone.zones.dir
+	fullName := m.getFilename(name, args...)
+
+	return fs.ReadFile(base, fullName)
+}
+
+func (m *Machine) getFilename(name string, args ...any) string {
+	if len(args) > 0 {
+		name = fmt.Sprintf(name, args...)
+	}
+
+	s := []string{
+		m.zone.Name,
+		m.Name,
+		name,
+	}
+
+	return filepath.Join(s...)
+}

pkg/zones/zones.go

@@ -31,6 +31,22 @@ type Zones struct {
 	Zones []*Zone `toml:"zones"`
 }
 
+// ForEachMachine calls a function for each Machine in the cluster
+func (m *Zones) ForEachMachine(fn func(*Machine)) {
+	for _, z := range m.Zones {
+		for _, p := range z.Machines {
+			fn(p)
+		}
+	}
+}
+
+// ForEachZone calls a function for each Zone in the cluster
+func (m *Zones) ForEachZone(fn func(*Zone)) {
+	for _, p := range m.Zones {
+		fn(p)
+	}
+}
+
 // NewFS builds a [Zones] tree using the given directory
 func NewFS(dir fs.FS, domain string) (*Zones, error) {
 	z := &Zones{