func (m *Manager) Set(container *configs.Config) error {
for name, path := range m.Paths {
sys, err := subsystems.Get(name)
if err == errSubsystemDoesNotExist || !cgroups.PathExists(path) {
continue
}
if err := sys.Set(path, container.Cgroups); err != nil {
return err
}
}
return 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
}
// Exists checks if all subsystem cgroups already exist
func (m *cgroupManagerImpl) Exists(name CgroupName) bool {
// Get map of all cgroup paths on the system for the particular cgroup
cgroupPaths := m.buildCgroupPaths(name)
// If even one cgroup path doesn't exist, then the cgroup doesn't exist.
for _, path := range cgroupPaths {
if !libcontainercgroups.PathExists(path) {
return false
}
}
return true
}
func (m *Manager) GetStats() (*cgroups.Stats, error) {
m.mu.Lock()
defer m.mu.Unlock()
stats := cgroups.NewStats()
for name, path := range m.Paths {
sys, err := subsystems.Get(name)
if err == errSubsystemDoesNotExist || !cgroups.PathExists(path) {
continue
}
if err := sys.GetStats(path, stats); err != nil {
return nil, err
}
}
return stats, nil
}
// Exists checks if all subsystem cgroups already exist
func (m *cgroupManagerImpl) Exists(name string) bool {
// Get map of all cgroup paths on the system for the particular cgroup
cgroupPaths := make(map[string]string, len(m.subsystems.MountPoints))
for key, val := range m.subsystems.MountPoints {
cgroupPaths[key] = path.Join(val, name)
}
// If even one cgroup doesn't exist we go on to create it
for _, path := range cgroupPaths {
if !libcontainercgroups.PathExists(path) {
return false
}
}
return true
}
// Exists checks if all subsystem cgroups already exist
func (m *cgroupManagerImpl) Exists(name string) bool {
// Get map of all cgroup paths on the system for the particular cgroup
cgroupPaths := make(map[string]string, len(m.subsystems.mountPoints))
for key, val := range m.subsystems.mountPoints {
cgroupPaths[key] = path.Join(val, name)
}
// If even one cgroup doesn't exist we go on to create it
// @TODO(dubstack) We skip check for systemd until we update
// libcontainer in vendor
for key, path := range cgroupPaths {
if key != "systemd" && !libcontainercgroups.PathExists(path) {
return false
}
}
return true
}
func setKernelMemory(path string, kernelMemoryLimit int64) error {
if path == "" {
return fmt.Errorf("no such directory for %s", cgroupKernelMemoryLimit)
}
if !cgroups.PathExists(filepath.Join(path, cgroupKernelMemoryLimit)) {
// kernel memory is not enabled on the system so we should do nothing
return nil
}
if err := ioutil.WriteFile(filepath.Join(path, cgroupKernelMemoryLimit), []byte(strconv.FormatInt(kernelMemoryLimit, 10)), 0700); err != nil {
// Check if the error number returned by the syscall is "EBUSY"
// The EBUSY signal is returned on attempts to write to the
// memory.kmem.limit_in_bytes file if the cgroup has children or
// once tasks have been attached to the cgroup
if pathErr, ok := err.(*os.PathError); ok {
if errNo, ok := pathErr.Err.(syscall.Errno); ok {
if errNo == syscall.EBUSY {
return fmt.Errorf("failed to set %s, because either tasks have already joined this cgroup or it has children", cgroupKernelMemoryLimit)
}
}
}
return fmt.Errorf("failed to write %v to %v: %v", kernelMemoryLimit, cgroupKernelMemoryLimit, err)
}
return nil
}
func (s *MemoryGroup) Apply(d *cgroupData) (err error) {
path, err := d.path("memory")
if err != nil && !cgroups.IsNotFound(err) {
return err
}
// reset error.
err = nil
if path == "" {
// Invalid input.
return fmt.Errorf("invalid path for memory cgroups: %+v", d)
}
defer func() {
if err != nil {
os.RemoveAll(path)
}
}()
if !cgroups.PathExists(path) {
if err = os.MkdirAll(path, 0755); err != nil {
return err
}
}
if memoryAssigned(d.config) {
// We have to set kernel memory here, as we can't change it once
// processes have been attached to the cgroup.
if err = s.SetKernelMemory(path, d.config); err != nil {
return err
}
}
// We need to join memory cgroup after set memory limits, because
// kmem.limit_in_bytes can only be set when the cgroup is empty.
if _, jerr := d.join("memory"); jerr != nil && !cgroups.IsNotFound(jerr) {
err = jerr
return err
}
return nil
}