add Set interface

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

cgroups/cgroups.go

@@ -31,6 +31,9 @@ type Manager interface {
 	// Returns cgroup paths to save in a state file and to be able to
 	// restore the object later.
 	GetPaths() map[string]string
+
+	// Set the cgroup as configured.
+	Set(container *configs.Config) error
 }
 
 type NotFoundError struct {

cgroups/fs/apply_raw.go

@@ -32,6 +32,8 @@ type subsystem interface {
 	Remove(*data) error
 	// Creates and joins the cgroup represented by data.
 	Apply(*data) error
+	// Set the cgroup represented by cgroup.
+	Set(path string, cgroup *configs.Cgroup) error
 }
 
 type Manager struct {
@@ -147,6 +149,20 @@ func (m *Manager) GetStats() (*cgroups.Stats, error) {
 	return stats, nil
 }
 
+func (m *Manager) Set(container *configs.Config) error {
+	for name, path := range m.Paths {
+		sys, ok := subsystems[name]
+		if !ok || !cgroups.PathExists(path) {
+			continue
+		}
+		if err := sys.Set(path, container.Cgroups); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 // Freeze toggles the container's freezer cgroup depending on the state
 // provided
 func (m *Manager) Freeze(state configs.FreezerState) error {

cgroups/fs/blkio.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"github.com/docker/libcontainer/cgroups"
+	"github.com/docker/libcontainer/configs"
 )
 
 type BlkioGroup struct {
@@ -29,6 +30,16 @@ func (s *BlkioGroup) Apply(d *data) error {
 	return nil
 }
 
+func (s *BlkioGroup) Set(path string, cgroup *configs.Cgroup) error {
+	if cgroup.BlkioWeight != 0 {
+		if err := writeFile(path, "blkio.weight", strconv.FormatInt(cgroup.BlkioWeight, 10)); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (s *BlkioGroup) Remove(d *data) error {
 	return removePath(d.path("blkio"))
 }

cgroups/fs/cpu.go

@@ -7,6 +7,7 @@ import (
 	"strconv"
 
 	"github.com/docker/libcontainer/cgroups"
+	"github.com/docker/libcontainer/configs"
 )
 
 type CpuGroup struct {
@@ -37,6 +38,26 @@ func (s *CpuGroup) Apply(d *data) error {
 	return nil
 }
 
+func (s *CpuGroup) Set(path string, cgroup *configs.Cgroup) error {
+	if cgroup.CpuShares != 0 {
+		if err := writeFile(path, "cpu.shares", strconv.FormatInt(cgroup.CpuShares, 10)); err != nil {
+			return err
+		}
+	}
+	if cgroup.CpuPeriod != 0 {
+		if err := writeFile(path, "cpu.cfs_period_us", strconv.FormatInt(cgroup.CpuPeriod, 10)); err != nil {
+			return err
+		}
+	}
+	if cgroup.CpuQuota != 0 {
+		if err := writeFile(path, "cpu.cfs_quota_us", strconv.FormatInt(cgroup.CpuQuota, 10)); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (s *CpuGroup) Remove(d *data) error {
 	return removePath(d.path("cpu"))
 }

cgroups/fs/cpuacct.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/docker/libcontainer/cgroups"
+	"github.com/docker/libcontainer/configs"
 	"github.com/docker/libcontainer/system"
 )
 
@@ -30,6 +31,10 @@ func (s *CpuacctGroup) Apply(d *data) error {
 	return nil
 }
 
+func (s *CpuacctGroup) Set(path string, cgroup *configs.Cgroup) error {
+	return nil
+}
+
 func (s *CpuacctGroup) Remove(d *data) error {
 	return removePath(d.path("cpuacct"))
 }

cgroups/fs/cpuset.go

@@ -8,6 +8,7 @@ import (
 	"strconv"
 
 	"github.com/docker/libcontainer/cgroups"
+	"github.com/docker/libcontainer/configs"
 )
 
 type CpusetGroup struct {
@@ -21,6 +22,22 @@ func (s *CpusetGroup) Apply(d *data) error {
 	return s.ApplyDir(dir, d.c.CpusetCpus, d.c.CpusetMems, d.pid)
 }
 
+func (s *CpusetGroup) Set(path string, cgroup *configs.Cgroup) error {
+	if cgroup.CpusetCpus != "" {
+		if err := writeFile(path, "cpuset.cpus", cgroup.CpusetCpus); err != nil {
+			return err
+		}
+	}
+
+	if cgroup.CpusetMems != "" {
+		if err := writeFile(path, "cpuset.mems", cgroup.CpusetMems); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (s *CpusetGroup) Remove(d *data) error {
 	return removePath(d.path("cpuset"))
 }

cgroups/fs/devices.go

@@ -1,6 +1,9 @@
 package fs
 
-import "github.com/docker/libcontainer/cgroups"
+import (
+	"github.com/docker/libcontainer/cgroups"
+	"github.com/docker/libcontainer/configs"
+)
 
 type DevicesGroup struct {
 }
@@ -25,6 +28,22 @@ func (s *DevicesGroup) Apply(d *data) error {
 	return nil
 }
 
+func (s *DevicesGroup) Set(path string, cgroup *configs.Cgroup) error {
+	if !cgroup.AllowAllDevices {
+		if err := writeFile(path, "devices.deny", "a"); err != nil {
+			return err
+		}
+
+		for _, dev := range cgroup.AllowedDevices {
+			if err := writeFile(path, "devices.allow", dev.CgroupString()); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
 func (s *DevicesGroup) Remove(d *data) error {
 	return removePath(d.path("devices"))
 }

cgroups/fs/freezer.go

@@ -42,6 +42,28 @@ func (s *FreezerGroup) Apply(d *data) error {
 	return nil
 }
 
+func (s *FreezerGroup) Set(path string, cgroup *configs.Cgroup) error {
+	switch cgroup.Freezer {
+	case configs.Frozen, configs.Thawed:
+		if err := writeFile(path, "freezer.state", string(cgroup.Freezer)); err != nil {
+			return err
+		}
+
+		for {
+			state, err := readFile(path, "freezer.state")
+			if err != nil {
+				return err
+			}
+			if strings.TrimSpace(state) == string(cgroup.Freezer) {
+				break
+			}
+			time.Sleep(1 * time.Millisecond)
+		}
+	}
+
+	return nil
+}
+
 func (s *FreezerGroup) Remove(d *data) error {
 	return removePath(d.path("freezer"))
 }

cgroups/fs/memory.go

@@ -8,6 +8,7 @@ import (
 	"strconv"
 
 	"github.com/docker/libcontainer/cgroups"
+	"github.com/docker/libcontainer/configs"
 )
 
 type MemoryGroup struct {
@@ -53,6 +54,32 @@ func (s *MemoryGroup) Apply(d *data) error {
 	return nil
 }
 
+func (s *MemoryGroup) Set(path string, cgroup *configs.Cgroup) error {
+	if cgroup.Memory != 0 {
+		if err := writeFile(path, "memory.limit_in_bytes", strconv.FormatInt(cgroup.Memory, 10)); err != nil {
+			return err
+		}
+	}
+	if cgroup.MemoryReservation != 0 {
+		if err := writeFile(path, "memory.soft_limit_in_bytes", strconv.FormatInt(cgroup.MemoryReservation, 10)); err != nil {
+			return err
+		}
+	}
+	// By default, MemorySwap is set to twice the size of Memory.
+	if cgroup.MemorySwap == 0 && cgroup.Memory != 0 {
+		if err := writeFile(path, "memory.memsw.limit_in_bytes", strconv.FormatInt(cgroup.Memory*2, 10)); err != nil {
+			return err
+		}
+	}
+	if cgroup.MemorySwap > 0 {
+		if err := writeFile(path, "memory.memsw.limit_in_bytes", strconv.FormatInt(cgroup.MemorySwap, 10)); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (s *MemoryGroup) Remove(d *data) error {
 	return removePath(d.path("memory"))
 }

cgroups/fs/perf_event.go

@@ -2,6 +2,7 @@ package fs
 
 import (
 	"github.com/docker/libcontainer/cgroups"
+	"github.com/docker/libcontainer/configs"
 )
 
 type PerfEventGroup struct {
@@ -15,6 +16,10 @@ func (s *PerfEventGroup) Apply(d *data) error {
 	return nil
 }
 
+func (s *PerfEventGroup) Set(path string, cgroup *configs.Cgroup) error {
+	return nil
+}
+
 func (s *PerfEventGroup) Remove(d *data) error {
 	return removePath(d.path("perf_event"))
 }

cgroups/systemd/apply_nosystemd.go

@@ -38,6 +38,10 @@ func (m *Manager) GetStats() (*cgroups.Stats, error) {
 	return nil, fmt.Errorf("Systemd not supported")
 }
 
+func (m *Manager) Set(container *configs.Config) error {
+	return nil, fmt.Errorf("Systemd not supported")
+}
+
 func (m *Manager) Freeze(state configs.FreezerState) error {
 	return fmt.Errorf("Systemd not supported")
 }

cgroups/systemd/apply_systemd.go

@@ -26,7 +26,10 @@ type Manager struct {
 }
 
 type subsystem interface {
-	GetStats(string, *cgroups.Stats) error
+	// Returns the stats, as 'stats', corresponding to the cgroup under 'path'.
+	GetStats(path string, stats *cgroups.Stats) error
+	// Set the cgroup represented by cgroup.
+	Set(path string, cgroup *configs.Cgroup) error
 }
 
 var subsystems = map[string]subsystem{
@@ -323,6 +326,10 @@ func (m *Manager) GetStats() (*cgroups.Stats, error) {
 	return stats, nil
 }
 
+func (m *Manager) Set(container *configs.Config) error {
+	panic("not implemented")
+}
+
 func getUnitName(c *configs.Cgroup) string {
 	return fmt.Sprintf("%s-%s.scope", c.Parent, c.Name)
 }

container_linux_test.go

@@ -29,6 +29,10 @@ func (m *mockCgroupManager) Apply(pid int) error {
 	return nil
 }
 
+func (m *mockCgroupManager) Set(container *configs.Config) error {
+	return nil
+}
+
 func (m *mockCgroupManager) Destroy() error {
 	return nil
 }