cgroup: add support for net_prio

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

cgroups/fs/net_prio.go

@@ -0,0 +1,40 @@
+package fs
+
+import (
+	"github.com/docker/libcontainer/cgroups"
+	"github.com/docker/libcontainer/configs"
+)
+
+type NetPrioGroup struct {
+}
+
+func (s *NetPrioGroup) Apply(d *data) error {
+	dir, err := d.join("net_prio")
+	if err != nil && !cgroups.IsNotFound(err) {
+		return err
+	}
+
+	if err := s.Set(dir, d.c); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (s *NetPrioGroup) Set(path string, cgroup *configs.Cgroup) error {
+	for _, prioMap := range cgroup.NetPrioIfpriomap {
+		if err := writeFile(path, "net_prio.ifpriomap", prioMap.CgroupString()); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (s *NetPrioGroup) Remove(d *data) error {
+	return removePath(d.path("net_prio"))
+}
+
+func (s *NetPrioGroup) GetStats(path string, stats *cgroups.Stats) error {
+	return nil
+}

cgroups/fs/net_prio_test.go

@@ -0,0 +1,36 @@
+package fs
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/docker/libcontainer/configs"
+)
+
+var (
+	prioMap = []*configs.IfPrioMap{
+		{
+			Interface: "test",
+			Priority:  5,
+		},
+	}
+)
+
+func TestNetPrioSetIfPrio(t *testing.T) {
+	helper := NewCgroupTestUtil("net_prio", t)
+	defer helper.cleanup()
+
+	helper.CgroupData.c.NetPrioIfpriomap = prioMap
+	netPrio := &NetPrioGroup{}
+	if err := netPrio.Set(helper.CgroupPath, helper.CgroupData.c); err != nil {
+		t.Fatal(err)
+	}
+
+	value, err := getCgroupParamString(helper.CgroupPath, "net_prio.ifpriomap")
+	if err != nil {
+		t.Fatalf("Failed to parse net_prio.ifpriomap - %s", err)
+	}
+	if !strings.Contains(value, "test 5") {
+		t.Fatal("Got the wrong value, set net_prio.ifpriomap failed.")
+	}
+}

cgroups/systemd/apply_systemd.go

@@ -41,6 +41,7 @@ var subsystems = map[string]subsystem{
 	"hugetlb":    &fs.HugetlbGroup{},
 	"perf_event": &fs.PerfEventGroup{},
 	"freezer":    &fs.FreezerGroup{},
+	"net_prio":   &fs.NetPrioGroup{},
 }
 
 const (
@@ -207,12 +208,16 @@ func (m *Manager) Apply(pid int) error {
 
 	}
 
-	// we need to manually join the freezer and cpuset cgroup in systemd
+	// we need to manually join the freezer, net_prio and cpuset cgroup in systemd
 	// because it does not currently support it via the dbus api.
 	if err := joinFreezer(c, pid); err != nil {
 		return err
 	}
 
+	if err := joinNetPrio(c, pid); err != nil {
+		return err
+	}
+
 	if err := joinCpuset(c, pid); err != nil {
 		return err
 	}
@@ -305,6 +310,16 @@ func joinFreezer(c *configs.Cgroup, pid int) error {
 	return nil
 }
 
+func joinNetPrio(c *configs.Cgroup, pid int) error {
+	path, err := join(c, "net_prio", pid)
+	if err != nil && !cgroups.IsNotFound(err) {
+		return err
+	}
+
+	netPrio := subsystems["net_prio"]
+	return netPrio.Set(path, c)
+}
+
 func getSubsystemPath(c *configs.Cgroup, subsystem string) (string, error) {
 	mountpoint, err := cgroups.FindCgroupMountpoint(subsystem)
 	if err != nil {

configs/cgroup.go

@@ -71,4 +71,7 @@ type Cgroup struct {
 
 	// Whether to disable OOM Killer
 	OomKillDisable bool `json:"oom_kill_disable"`
+
+	// Set priority of network traffic for container
+	NetPrioIfpriomap []*IfPrioMap `json:"net_prio_ifpriomap"`
 }

configs/interface_priority_map.go

@@ -0,0 +1,14 @@
+package configs
+
+import (
+	"fmt"
+)
+
+type IfPrioMap struct {
+	Interface string `json:"interface"`
+	Priority  int64  `json:"priority"`
+}
+
+func (i *IfPrioMap) CgroupString() string {
+	return fmt.Sprintf("%s %d", i.Interface, i.Priority)
+}