zones: add methods to work with files at the root of m/

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

pkg/zones/zones_file.go

@@ -0,0 +1,46 @@
+package zones
+
+import (
+	"fmt"
+	"io"
+	"os"
+
+	fs "github.com/hack-pad/hackpadfs"
+)
+
+// OpenFile opens a file on the cluster's config directory with the specified flags
+func (m *Zones) OpenFile(name string, flags int, args ...any) (fs.File, error) {
+	if len(args) > 0 {
+		name = fmt.Sprintf(name, args...)
+	}
+
+	return fs.OpenFile(m.dir, name, flags, 0644)
+}
+
+// CreateTruncFile creates or truncates a file on the cluster's config directory
+func (m *Zones) 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 cluster's config directory
+func (m *Zones) CreateFile(name string, args ...any) (io.WriteCloser, error) {
+	return m.openWriter(name, os.O_CREATE, args...)
+}
+
+func (m *Zones) 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
+}
+
+// ReadFile reads a file from the cluster's config directory
+func (m *Zones) ReadFile(name string, args ...any) ([]byte, error) {
+	if len(args) > 0 {
+		name = fmt.Sprintf(name, args...)
+	}
+
+	return fs.ReadFile(m.dir, name)
+}