ebpf: create map's parent directory if it doesn't exist

When dealing with a pinned map in the ebpf.OpenOrCreate method, make
sure the map's parent directory does exist (and try to create it in case
it doesn't).

Signed-off-by: Gilberto Bertin <gilberto@isovalent.com>

pkg/ebpf/map.go

@@ -17,6 +17,8 @@ package ebpf
 import (
 	"errors"
 	"fmt"
+	"os"
+	"path/filepath"
 
 	"github.com/cilium/cilium/api/v1/models"
 	"github.com/cilium/cilium/pkg/bpf"
@@ -73,6 +75,20 @@ func (m *Map) OpenOrCreate() error {
 
 	path := bpf.MapPath(m.spec.Name)
 
+	if m.spec.Pinning == ciliumebpf.PinByName {
+		mapDir := filepath.Dir(path)
+
+		if _, err := os.Stat(mapDir); os.IsNotExist(err) {
+			if err = os.MkdirAll(mapDir, 0755); err != nil {
+				return &os.PathError{
+					Op:   "Unable create map base directory",
+					Path: path,
+					Err:  err,
+				}
+			}
+		}
+	}
+
 	newMap, err := ciliumebpf.NewMapWithOptions(m.spec, opts)
 	if err != nil {
 		if !errors.Is(err, ciliumebpf.ErrMapIncompatible) {