add cgroup network test for runtime

Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>

Author: Ma Shimiao

validation/linux_cgroups_network.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/opencontainers/runtime-tools/cgroups"
+	"github.com/opencontainers/runtime-tools/validation/util"
+)
+
+func main() {
+	var id, prio uint32 = 255, 10
+	ifName := "lo"
+	g := util.GetDefaultGenerator()
+	g.SetLinuxCgroupsPath("/test")
+	g.SetLinuxResourcesNetworkClassID(id)
+	err := util.RuntimeOutsideValidate(g, func(path string) error {
+		cg, err := cgroups.FindCgroup()
+		if err != nil {
+			return err
+		}
+		lnd, err := cg.GetNetworkData(path)
+		if err != nil {
+			return err
+		}
+		if *lnd.ClassID != id {
+			return fmt.Errorf("network ID is not set correctly, expect: %d, actual: %d", id, lnd.ClassID)
+		}
+		found := false
+		for _, lip := range lnd.Priorities {
+			if lip.Name == ifName {
+				found = true
+				if lip.Priority != prio {
+					return fmt.Errorf("network priority for %s is not set correctly, expect: %d, actual: %d", ifName, prio, lip.Priority)
+				}
+			}
+		}
+		if !found {
+			return fmt.Errorf("network priority for %s is not set correctly", ifName)
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		util.Fatal(err)
+	}
+}