func switchCgroup(src, target int) error {
cgroupFile := fmt.Sprintf("/proc/%d/cgroup", target)
f, err := os.Open(cgroupFile)
if err != nil {
return err
}
defer f.Close()
targetCgroups := map[string]string{}
s := bufio.NewScanner(f)
for s.Scan() {
text := s.Text()
parts := strings.Split(text, ":")
subparts := strings.Split(parts[1], "=")
subsystem := subparts[0]
if len(subparts) > 1 {
subsystem = subparts[1]
}
targetPath := fmt.Sprintf("/host/sys/fs/cgroup/%s%s", subsystem, parts[2])
log.Infof("Moving Docker to cgroup %s", targetPath)
targetCgroups[subsystem] = targetPath
}
if err := s.Err(); err != nil {
return err
}
return cgroups.EnterPid(targetCgroups, src)
}
func (p *setnsProcess) start() (err error) {
defer p.parentPipe.Close()
if err = p.execSetns(); err != nil {
return newSystemError(err)
}
if len(p.cgroupPaths) > 0 {
if err := cgroups.EnterPid(p.cgroupPaths, p.pid()); err != nil {
return newSystemError(err)
}
}
if err := json.NewEncoder(p.parentPipe).Encode(p.config); err != nil {
return newSystemError(err)
}
if err := syscall.Shutdown(int(p.parentPipe.Fd()), syscall.SHUT_WR); err != nil {
return newSystemError(err)
}
// wait for the child process to fully complete and receive an error message
// if one was encoutered
var ierr *genericError
if err := json.NewDecoder(p.parentPipe).Decode(&ierr); err != nil && err != io.EOF {
return newSystemError(err)
}
if ierr != nil {
return newSystemError(ierr)
}
return nil
}
func (m *Manager) Apply(pid int) (err error) {
if m.Cgroups == nil {
return nil
}
var c = m.Cgroups
d, err := getCgroupData(m.Cgroups, pid)
if err != nil {
return err
}
if c.Paths != nil {
paths := make(map[string]string)
for name, path := range c.Paths {
_, err := d.path(name)
if err != nil {
if cgroups.IsNotFound(err) {
continue
}
return err
}
paths[name] = path
}
m.Paths = paths
return cgroups.EnterPid(m.Paths, pid)
}
paths := make(map[string]string)
defer func() {
if err != nil {
cgroups.RemovePaths(paths)
}
}()
for _, sys := range subsystems {
if err := sys.Apply(d); err != nil {
return err
}
// TODO: Apply should, ideally, be reentrant or be broken up into a separate
// create and join phase so that the cgroup hierarchy for a container can be
// created then join consists of writing the process pids to cgroup.procs
p, err := d.path(sys.Name())
if err != nil {
if cgroups.IsNotFound(err) {
continue
}
return err
}
paths[sys.Name()] = p
}
m.Paths = paths
return nil
}
func (m *Manager) Apply(pid int) (err error) {
if m.Cgroups == nil {
return nil
}
var c = m.Cgroups
d, err := getCgroupData(m.Cgroups, pid)
if err != nil {
return err
}
if c.Paths != nil {
paths := make(map[string]string)
for name, path := range c.Paths {
_, err := d.path(name)
if err != nil {
if cgroups.IsNotFound(err) {
continue
}
return err
}
paths[name] = path
}
m.Paths = paths
return cgroups.EnterPid(m.Paths, pid)
}
m.mu.Lock()
defer m.mu.Unlock()
paths := make(map[string]string)
for _, sys := range subsystems {
if err := sys.Apply(d); err != nil {
return err
}
// TODO: Apply should, ideally, be reentrant or be broken up into a separate
// create and join phase so that the cgroup hierarchy for a container can be
// created then join consists of writing the process pids to cgroup.procs
p, err := d.path(sys.Name())
if err != nil {
// The non-presence of the devices subsystem is
// considered fatal for security reasons.
if cgroups.IsNotFound(err) && sys.Name() != "devices" {
continue
}
return err
}
paths[sys.Name()] = p
}
m.Paths = paths
return nil
}
func (p *setnsProcess) start() (err error) {
defer p.parentPipe.Close()
err = p.cmd.Start()
p.childPipe.Close()
p.rootDir.Close()
if err != nil {
return newSystemErrorWithCause(err, "starting setns process")
}
if p.bootstrapData != nil {
if _, err := io.Copy(p.parentPipe, p.bootstrapData); err != nil {
return newSystemErrorWithCause(err, "copying bootstrap data to pipe")
}
}
if err = p.execSetns(); err != nil {
return newSystemErrorWithCause(err, "executing setns process")
}
if len(p.cgroupPaths) > 0 {
if err := cgroups.EnterPid(p.cgroupPaths, p.pid()); err != nil {
return newSystemErrorWithCausef(err, "adding pid %d to cgroups", p.pid())
}
}
// set oom_score_adj
if err := setOomScoreAdj(p.config.Config.OomScoreAdj, p.pid()); err != nil {
return newSystemErrorWithCause(err, "setting oom score")
}
// set rlimits, this has to be done here because we lose permissions
// to raise the limits once we enter a user-namespace
if err := setupRlimits(p.config.Rlimits, p.pid()); err != nil {
return newSystemErrorWithCause(err, "setting rlimits for process")
}
if err := utils.WriteJSON(p.parentPipe, p.config); err != nil {
return newSystemErrorWithCause(err, "writing config to pipe")
}
if err := syscall.Shutdown(int(p.parentPipe.Fd()), syscall.SHUT_WR); err != nil {
return newSystemErrorWithCause(err, "calling shutdown on init pipe")
}
// wait for the child process to fully complete and receive an error message
// if one was encoutered
var ierr *genericError
if err := json.NewDecoder(p.parentPipe).Decode(&ierr); err != nil && err != io.EOF {
return newSystemErrorWithCause(err, "decoding init error from pipe")
}
// Must be done after Shutdown so the child will exit and we can wait for it.
if ierr != nil {
p.wait()
return ierr
}
return nil
}
func (p *setnsProcess) start() (err error) {
defer p.parentPipe.Close()
err = p.cmd.Start()
p.childPipe.Close()
if err != nil {
return newSystemError(err)
}
if p.bootstrapData != nil {
if _, err := io.Copy(p.parentPipe, p.bootstrapData); err != nil {
return newSystemError(err)
}
}
if err = p.execSetns(); err != nil {
return newSystemError(err)
}
if len(p.cgroupPaths) > 0 {
if err := cgroups.EnterPid(p.cgroupPaths, p.pid()); err != nil {
return newSystemError(err)
}
}
if err := utils.WriteJSON(p.parentPipe, p.config); err != nil {
return newSystemError(err)
}
// set oom_score_adj
if err := setOomScoreAdj(p.config.Config.OomScoreAdj, p.pid()); err != nil {
return newSystemError(err)
}
if err := syscall.Shutdown(int(p.parentPipe.Fd()), syscall.SHUT_WR); err != nil {
return newSystemError(err)
}
// wait for the child process to fully complete and receive an error message
// if one was encoutered
var ierr *genericError
if err := json.NewDecoder(p.parentPipe).Decode(&ierr); err != nil && err != io.EOF {
return newSystemError(err)
}
// Must be done after Shutdown so the child will exit and we can wait for it.
if ierr != nil {
p.wait()
return newSystemError(ierr)
}
return nil
}
func (m *Manager) Apply(pid int) error {
var (
c = m.Cgroups
unitName = getUnitName(c)
slice = "system.slice"
properties []systemdDbus.Property
)
if c.Paths != nil {
paths := make(map[string]string)
for name, path := range c.Paths {
_, err := getSubsystemPath(m.Cgroups, name)
if err != nil {
// Don't fail if a cgroup hierarchy was not found, just skip this subsystem
if cgroups.IsNotFound(err) {
continue
}
return err
}
paths[name] = path
}
m.Paths = paths
return cgroups.EnterPid(m.Paths, pid)
}
if c.Parent != "" {
slice = c.Parent
}
properties = append(properties,
systemdDbus.PropSlice(slice),
systemdDbus.PropDescription("docker container "+c.Name),
newProp("PIDs", []uint32{uint32(pid)}),
// This is only supported on systemd versions 218 and above.
newProp("Delegate", true),
)
// Always enable accounting, this gets us the same behaviour as the fs implementation,
// plus the kernel has some problems with joining the memory cgroup at a later time.
properties = append(properties,
newProp("MemoryAccounting", true),
newProp("CPUAccounting", true),
newProp("BlockIOAccounting", true))
if hasTransientDefaultDependencies {
properties = append(properties,
newProp("DefaultDependencies", false))
}
if c.Resources.Memory != 0 {
properties = append(properties,
newProp("MemoryLimit", uint64(c.Resources.Memory)))
}
if c.Resources.CpuShares != 0 {
properties = append(properties,
newProp("CPUShares", uint64(c.Resources.CpuShares)))
}
if c.Resources.BlkioWeight != 0 {
properties = append(properties,
newProp("BlockIOWeight", uint64(c.Resources.BlkioWeight)))
}
// We need to set kernel memory before processes join cgroup because
// kmem.limit_in_bytes can only be set when the cgroup is empty.
// And swap memory limit needs to be set after memory limit, only
// memory limit is handled by systemd, so it's kind of ugly here.
if c.Resources.KernelMemory > 0 {
if err := setKernelMemory(c); err != nil {
return err
}
}
if _, err := theConn.StartTransientUnit(unitName, "replace", properties, nil); err != nil {
return err
}
if err := joinCgroups(c, pid); err != nil {
return err
}
paths := make(map[string]string)
for _, s := range subsystems {
subsystemPath, err := getSubsystemPath(m.Cgroups, s.Name())
if err != nil {
// Don't fail if a cgroup hierarchy was not found, just skip this subsystem
if cgroups.IsNotFound(err) {
continue
}
return err
}
paths[s.Name()] = subsystemPath
}
m.Paths = paths
return nil
}
func (m *Manager) Apply(pid int) error {
var (
c = m.Cgroups
unitName = getUnitName(c)
slice = "system.slice"
properties []systemdDbus.Property
)
if c.Paths != nil {
paths := make(map[string]string)
for name, path := range c.Paths {
_, err := getSubsystemPath(m.Cgroups, name)
if err != nil {
// Don't fail if a cgroup hierarchy was not found, just skip this subsystem
if cgroups.IsNotFound(err) {
continue
}
return err
}
paths[name] = path
}
m.Paths = paths
return cgroups.EnterPid(m.Paths, pid)
}
if c.Parent != "" {
slice = c.Parent
}
properties = append(properties,
systemdDbus.PropSlice(slice),
systemdDbus.PropDescription("docker container "+c.Name),
newProp("PIDs", []uint32{uint32(pid)}),
)
// Always enable accounting, this gets us the same behaviour as the fs implementation,
// plus the kernel has some problems with joining the memory cgroup at a later time.
properties = append(properties,
newProp("MemoryAccounting", true),
newProp("CPUAccounting", true),
newProp("BlockIOAccounting", true))
if hasTransientDefaultDependencies {
properties = append(properties,
newProp("DefaultDependencies", false))
}
if c.Resources.Memory != 0 {
properties = append(properties,
newProp("MemoryLimit", uint64(c.Resources.Memory)))
}
if c.Resources.CpuShares != 0 {
properties = append(properties,
newProp("CPUShares", uint64(c.Resources.CpuShares)))
}
if c.Resources.BlkioWeight != 0 {
properties = append(properties,
newProp("BlockIOWeight", uint64(c.Resources.BlkioWeight)))
}
// We need to set kernel memory before processes join cgroup because
// kmem.limit_in_bytes can only be set when the cgroup is empty.
// And swap memory limit needs to be set after memory limit, only
// memory limit is handled by systemd, so it's kind of ugly here.
if c.Resources.KernelMemory > 0 {
if err := setKernelMemory(c); err != nil {
return err
}
}
if _, err := theConn.StartTransientUnit(unitName, "replace", properties, nil); err != nil {
return err
}
if err := joinDevices(c, pid); err != nil {
return err
}
// TODO: CpuQuota and CpuPeriod not available in systemd
// we need to manually join the cpu.cfs_quota_us and cpu.cfs_period_us
if err := joinCpu(c, pid); err != nil {
return err
}
// TODO: MemoryReservation and MemorySwap not available in systemd
if err := joinMemory(c, pid); err != nil {
return err
}
// we need to manually join the freezer, net_cls, net_prio, pids 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 := joinNetCls(c, pid); err != nil {
return err
}
if err := joinPids(c, pid); err != nil {
return err
}
if err := joinCpuset(c, pid); err != nil {
return err
}
if err := joinHugetlb(c, pid); err != nil {
return err
}
if err := joinPerfEvent(c, pid); err != nil {
return err
}
// FIXME: Systemd does have `BlockIODeviceWeight` property, but we got problem
// using that (at least on systemd 208, see https://github.com/opencontainers/runc/libcontainer/pull/354),
// so use fs work around for now.
if err := joinBlkio(c, pid); err != nil {
return err
}
paths := make(map[string]string)
for _, s := range subsystems {
subsystemPath, err := getSubsystemPath(m.Cgroups, s.Name())
if err != nil {
// Don't fail if a cgroup hierarchy was not found, just skip this subsystem
if cgroups.IsNotFound(err) {
continue
}
return err
}
paths[s.Name()] = subsystemPath
}
m.Paths = paths
return nil
}
func (p *setnsProcess) start() (err error) {
defer p.parentPipe.Close()
err = p.cmd.Start()
p.childPipe.Close()
p.rootDir.Close()
if err != nil {
return newSystemErrorWithCause(err, "starting setns process")
}
if p.bootstrapData != nil {
if _, err := io.Copy(p.parentPipe, p.bootstrapData); err != nil {
return newSystemErrorWithCause(err, "copying bootstrap data to pipe")
}
}
if err = p.execSetns(); err != nil {
return newSystemErrorWithCause(err, "executing setns process")
}
if len(p.cgroupPaths) > 0 {
if err := cgroups.EnterPid(p.cgroupPaths, p.pid()); err != nil {
return newSystemErrorWithCausef(err, "adding pid %d to cgroups", p.pid())
}
}
// set oom_score_adj
if err := setOomScoreAdj(p.config.Config.OomScoreAdj, p.pid()); err != nil {
return newSystemErrorWithCause(err, "setting oom score")
}
// set rlimits, this has to be done here because we lose permissions
// to raise the limits once we enter a user-namespace
if err := setupRlimits(p.config.Rlimits, p.pid()); err != nil {
return newSystemErrorWithCause(err, "setting rlimits for process")
}
if err := utils.WriteJSON(p.parentPipe, p.config); err != nil {
return newSystemErrorWithCause(err, "writing config to pipe")
}
ierr := parseSync(p.parentPipe, func(sync *syncT) error {
switch sync.Type {
case procConsole:
if err := writeSync(p.parentPipe, procConsoleReq); err != nil {
return newSystemErrorWithCause(err, "writing syncT 'request fd'")
}
masterFile, err := utils.RecvFd(p.parentPipe)
if err != nil {
return newSystemErrorWithCause(err, "getting master pty from child pipe")
}
if p.process.consoleChan == nil {
// TODO: Don't panic here, do something more sane.
panic("consoleChan is nil")
}
p.process.consoleChan <- masterFile
if err := writeSync(p.parentPipe, procConsoleAck); err != nil {
return newSystemErrorWithCause(err, "writing syncT 'ack fd'")
}
case procReady:
// This shouldn't happen.
panic("unexpected procReady in setns")
case procHooks:
// This shouldn't happen.
panic("unexpected procHooks in setns")
default:
return newSystemError(fmt.Errorf("invalid JSON payload from child"))
}
return nil
})
if err := syscall.Shutdown(int(p.parentPipe.Fd()), syscall.SHUT_WR); err != nil {
return newSystemErrorWithCause(err, "calling shutdown on init pipe")
}
// Must be done after Shutdown so the child will exit and we can wait for it.
if ierr != nil {
p.wait()
return ierr
}
return nil
}
func (m *Manager) Apply(pid int) error {
var (
c = m.Cgroups
unitName = getUnitName(c)
slice = "system.slice"
properties []systemdDbus.Property
)
if c.Paths != nil {
paths := make(map[string]string)
for name, path := range c.Paths {
_, err := getSubsystemPath(m.Cgroups, name)
if err != nil {
// Don't fail if a cgroup hierarchy was not found, just skip this subsystem
if cgroups.IsNotFound(err) {
continue
}
return err
}
paths[name] = path
}
m.Paths = paths
return cgroups.EnterPid(m.Paths, pid)
}
if c.Parent != "" {
slice = c.Parent
}
properties = append(properties, systemdDbus.PropDescription("libcontainer container "+c.Name))
// if we create a slice, the parent is defined via a Wants=
if strings.HasSuffix(unitName, ".slice") {
// This was broken until systemd v229, but has been back-ported on RHEL environments >= 219
if !hasStartTransientSliceUnit {
return fmt.Errorf("systemd version does not support ability to start a slice as transient unit")
}
properties = append(properties, systemdDbus.PropWants(slice))
} else {
// otherwise, we use Slice=
properties = append(properties, systemdDbus.PropSlice(slice))
}
// only add pid if its valid, -1 is used w/ general slice creation.
if pid != -1 {
properties = append(properties, newProp("PIDs", []uint32{uint32(pid)}))
}
if hasDelegate {
// This is only supported on systemd versions 218 and above.
properties = append(properties, newProp("Delegate", true))
}
// Always enable accounting, this gets us the same behaviour as the fs implementation,
// plus the kernel has some problems with joining the memory cgroup at a later time.
properties = append(properties,
newProp("MemoryAccounting", true),
newProp("CPUAccounting", true),
newProp("BlockIOAccounting", true))
if hasTransientDefaultDependencies {
properties = append(properties,
newProp("DefaultDependencies", false))
}
if c.Resources.Memory != 0 {
properties = append(properties,
newProp("MemoryLimit", uint64(c.Resources.Memory)))
}
if c.Resources.CpuShares != 0 {
properties = append(properties,
newProp("CPUShares", uint64(c.Resources.CpuShares)))
}
if c.Resources.BlkioWeight != 0 {
properties = append(properties,
newProp("BlockIOWeight", uint64(c.Resources.BlkioWeight)))
}
// We have to set kernel memory here, as we can't change it once
// processes have been attached to the cgroup.
if c.Resources.KernelMemory != 0 {
if err := setKernelMemory(c); err != nil {
return err
}
}
if _, err := theConn.StartTransientUnit(unitName, "replace", properties, nil); err != nil {
return err
}
if err := joinCgroups(c, pid); err != nil {
return err
}
paths := make(map[string]string)
for _, s := range subsystems {
subsystemPath, err := getSubsystemPath(m.Cgroups, s.Name())
if err != nil {
// Don't fail if a cgroup hierarchy was not found, just skip this subsystem
if cgroups.IsNotFound(err) {
continue
}
return err
}
paths[s.Name()] = subsystemPath
}
m.Paths = paths
return nil
}