zones: Machine.CreateFile() and Machine.CreateTruncFile()

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

pkg/zones/machine_file.go

@@ -2,6 +2,7 @@ package zones
 
 import (
 	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 
@@ -16,6 +17,25 @@ func (m *Machine) OpenFile(name string, flags int, args ...any) (fs.File, error)
 	return fs.OpenFile(base, fullName, flags, 0644)
 }
 
+// CreateTruncFile creates or truncates a file on the machine's config directory
+func (m *Machine) CreateTruncFile(name string, args ...any) (io.WriteCloser, error) {
+	return m.openWriter(name, os.O_CREATE|os.O_TRUNC, args...)
+}
+
+// CreateFile creates a file on the machine's config directory
+func (m *Machine) CreateFile(name string, args ...any) (io.WriteCloser, error) {
+	return m.openWriter(name, os.O_CREATE, args...)
+}
+
+func (m *Machine) openWriter(name string, flags int, args ...any) (io.WriteCloser, error) {
+	f, err := m.OpenFile(name, os.O_WRONLY|flags, args...)
+	if err != nil {
+		return nil, err
+	}
+
+	return f.(io.WriteCloser), nil
+}
+
 // RemoveFile deletes a file from the machine's config directory
 func (m *Machine) RemoveFile(name string, args ...any) error {
 	base := m.zone.zones.dir