oci: join crio-conmon for cgroupfs

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

vendor/github.com/containerd/cgroups/net_prio.go

@@ -0,0 +1,50 @@
+package cgroups
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func NewNetPrio(root string) *netprioController {
+	return &netprioController{
+		root: filepath.Join(root, string(NetPrio)),
+	}
+}
+
+type netprioController struct {
+	root string
+}
+
+func (n *netprioController) Name() Name {
+	return NetPrio
+}
+
+func (n *netprioController) Path(path string) string {
+	return filepath.Join(n.root, path)
+}
+
+func (n *netprioController) Create(path string, resources *specs.LinuxResources) error {
+	if err := os.MkdirAll(n.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	if resources.Network != nil {
+		for _, prio := range resources.Network.Priorities {
+			if err := ioutil.WriteFile(
+				filepath.Join(n.Path(path), "net_prio_ifpriomap"),
+				formatPrio(prio.Name, prio.Priority),
+				defaultFilePerm,
+			); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func formatPrio(name string, prio uint32) []byte {
+	return []byte(fmt.Sprintf("%s %d", name, prio))
+}