mirror of https://github.com/k3s-io/k3s
446 lines
9.3 KiB
Go
446 lines
9.3 KiB
Go
/*
|
|
Copyright The containerd Authors.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package cgroups
|
|
|
|
import (
|
|
"fmt"
|
|
"io/ioutil"
|
|
"os"
|
|
"path/filepath"
|
|
"strconv"
|
|
"strings"
|
|
"sync"
|
|
|
|
specs "github.com/opencontainers/runtime-spec/specs-go"
|
|
"github.com/pkg/errors"
|
|
)
|
|
|
|
// New returns a new control via the cgroup cgroups interface
|
|
func New(hierarchy Hierarchy, path Path, resources *specs.LinuxResources) (Cgroup, error) {
|
|
subsystems, err := hierarchy()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
for _, s := range subsystems {
|
|
if err := initializeSubsystem(s, path, resources); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
return &cgroup{
|
|
path: path,
|
|
subsystems: subsystems,
|
|
}, nil
|
|
}
|
|
|
|
// Load will load an existing cgroup and allow it to be controlled
|
|
func Load(hierarchy Hierarchy, path Path) (Cgroup, error) {
|
|
subsystems, err := hierarchy()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// check the the subsystems still exist
|
|
for _, s := range pathers(subsystems) {
|
|
p, err := path(s.Name())
|
|
if err != nil {
|
|
if os.IsNotExist(errors.Cause(err)) {
|
|
return nil, ErrCgroupDeleted
|
|
}
|
|
return nil, err
|
|
}
|
|
if _, err := os.Lstat(s.Path(p)); err != nil {
|
|
if os.IsNotExist(err) {
|
|
return nil, ErrCgroupDeleted
|
|
}
|
|
return nil, err
|
|
}
|
|
}
|
|
return &cgroup{
|
|
path: path,
|
|
subsystems: subsystems,
|
|
}, nil
|
|
}
|
|
|
|
type cgroup struct {
|
|
path Path
|
|
|
|
subsystems []Subsystem
|
|
mu sync.Mutex
|
|
err error
|
|
}
|
|
|
|
// New returns a new sub cgroup
|
|
func (c *cgroup) New(name string, resources *specs.LinuxResources) (Cgroup, error) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return nil, c.err
|
|
}
|
|
path := subPath(c.path, name)
|
|
for _, s := range c.subsystems {
|
|
if err := initializeSubsystem(s, path, resources); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
return &cgroup{
|
|
path: path,
|
|
subsystems: c.subsystems,
|
|
}, nil
|
|
}
|
|
|
|
// Subsystems returns all the subsystems that are currently being
|
|
// consumed by the group
|
|
func (c *cgroup) Subsystems() []Subsystem {
|
|
return c.subsystems
|
|
}
|
|
|
|
// Add moves the provided process into the new cgroup
|
|
func (c *cgroup) Add(process Process) error {
|
|
if process.Pid <= 0 {
|
|
return ErrInvalidPid
|
|
}
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return c.err
|
|
}
|
|
return c.add(process)
|
|
}
|
|
|
|
func (c *cgroup) add(process Process) error {
|
|
for _, s := range pathers(c.subsystems) {
|
|
p, err := c.path(s.Name())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := ioutil.WriteFile(
|
|
filepath.Join(s.Path(p), cgroupProcs),
|
|
[]byte(strconv.Itoa(process.Pid)),
|
|
defaultFilePerm,
|
|
); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// AddTask moves the provided tasks (threads) into the new cgroup
|
|
func (c *cgroup) AddTask(process Process) error {
|
|
if process.Pid <= 0 {
|
|
return ErrInvalidPid
|
|
}
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return c.err
|
|
}
|
|
return c.addTask(process)
|
|
}
|
|
|
|
func (c *cgroup) addTask(process Process) error {
|
|
for _, s := range pathers(c.subsystems) {
|
|
p, err := c.path(s.Name())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := ioutil.WriteFile(
|
|
filepath.Join(s.Path(p), cgroupTasks),
|
|
[]byte(strconv.Itoa(process.Pid)),
|
|
defaultFilePerm,
|
|
); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Delete will remove the control group from each of the subsystems registered
|
|
func (c *cgroup) Delete() error {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return c.err
|
|
}
|
|
var errors []string
|
|
for _, s := range c.subsystems {
|
|
if d, ok := s.(deleter); ok {
|
|
sp, err := c.path(s.Name())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := d.Delete(sp); err != nil {
|
|
errors = append(errors, string(s.Name()))
|
|
}
|
|
continue
|
|
}
|
|
if p, ok := s.(pather); ok {
|
|
sp, err := c.path(s.Name())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
path := p.Path(sp)
|
|
if err := remove(path); err != nil {
|
|
errors = append(errors, path)
|
|
}
|
|
}
|
|
}
|
|
if len(errors) > 0 {
|
|
return fmt.Errorf("cgroups: unable to remove paths %s", strings.Join(errors, ", "))
|
|
}
|
|
c.err = ErrCgroupDeleted
|
|
return nil
|
|
}
|
|
|
|
// Stat returns the current metrics for the cgroup
|
|
func (c *cgroup) Stat(handlers ...ErrorHandler) (*Metrics, error) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return nil, c.err
|
|
}
|
|
if len(handlers) == 0 {
|
|
handlers = append(handlers, errPassthrough)
|
|
}
|
|
var (
|
|
stats = &Metrics{
|
|
CPU: &CPUStat{
|
|
Throttling: &Throttle{},
|
|
Usage: &CPUUsage{},
|
|
},
|
|
}
|
|
wg = &sync.WaitGroup{}
|
|
errs = make(chan error, len(c.subsystems))
|
|
)
|
|
for _, s := range c.subsystems {
|
|
if ss, ok := s.(stater); ok {
|
|
sp, err := c.path(s.Name())
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
wg.Add(1)
|
|
go func() {
|
|
defer wg.Done()
|
|
if err := ss.Stat(sp, stats); err != nil {
|
|
for _, eh := range handlers {
|
|
if herr := eh(err); herr != nil {
|
|
errs <- herr
|
|
}
|
|
}
|
|
}
|
|
}()
|
|
}
|
|
}
|
|
wg.Wait()
|
|
close(errs)
|
|
for err := range errs {
|
|
return nil, err
|
|
}
|
|
return stats, nil
|
|
}
|
|
|
|
// Update updates the cgroup with the new resource values provided
|
|
//
|
|
// Be prepared to handle EBUSY when trying to update a cgroup with
|
|
// live processes and other operations like Stats being performed at the
|
|
// same time
|
|
func (c *cgroup) Update(resources *specs.LinuxResources) error {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return c.err
|
|
}
|
|
for _, s := range c.subsystems {
|
|
if u, ok := s.(updater); ok {
|
|
sp, err := c.path(s.Name())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := u.Update(sp, resources); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Processes returns the processes running inside the cgroup along
|
|
// with the subsystem used, pid, and path
|
|
func (c *cgroup) Processes(subsystem Name, recursive bool) ([]Process, error) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return nil, c.err
|
|
}
|
|
return c.processes(subsystem, recursive)
|
|
}
|
|
|
|
func (c *cgroup) processes(subsystem Name, recursive bool) ([]Process, error) {
|
|
s := c.getSubsystem(subsystem)
|
|
sp, err := c.path(subsystem)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
path := s.(pather).Path(sp)
|
|
var processes []Process
|
|
err = filepath.Walk(path, func(p string, info os.FileInfo, err error) error {
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if !recursive && info.IsDir() {
|
|
if p == path {
|
|
return nil
|
|
}
|
|
return filepath.SkipDir
|
|
}
|
|
dir, name := filepath.Split(p)
|
|
if name != cgroupProcs {
|
|
return nil
|
|
}
|
|
procs, err := readPids(dir, subsystem)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
processes = append(processes, procs...)
|
|
return nil
|
|
})
|
|
return processes, err
|
|
}
|
|
|
|
// Freeze freezes the entire cgroup and all the processes inside it
|
|
func (c *cgroup) Freeze() error {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return c.err
|
|
}
|
|
s := c.getSubsystem(Freezer)
|
|
if s == nil {
|
|
return ErrFreezerNotSupported
|
|
}
|
|
sp, err := c.path(Freezer)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return s.(*freezerController).Freeze(sp)
|
|
}
|
|
|
|
// Thaw thaws out the cgroup and all the processes inside it
|
|
func (c *cgroup) Thaw() error {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return c.err
|
|
}
|
|
s := c.getSubsystem(Freezer)
|
|
if s == nil {
|
|
return ErrFreezerNotSupported
|
|
}
|
|
sp, err := c.path(Freezer)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return s.(*freezerController).Thaw(sp)
|
|
}
|
|
|
|
// OOMEventFD returns the memory cgroup's out of memory event fd that triggers
|
|
// when processes inside the cgroup receive an oom event. Returns
|
|
// ErrMemoryNotSupported if memory cgroups is not supported.
|
|
func (c *cgroup) OOMEventFD() (uintptr, error) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return 0, c.err
|
|
}
|
|
s := c.getSubsystem(Memory)
|
|
if s == nil {
|
|
return 0, ErrMemoryNotSupported
|
|
}
|
|
sp, err := c.path(Memory)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
return s.(*memoryController).OOMEventFD(sp)
|
|
}
|
|
|
|
// State returns the state of the cgroup and its processes
|
|
func (c *cgroup) State() State {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
c.checkExists()
|
|
if c.err != nil && c.err == ErrCgroupDeleted {
|
|
return Deleted
|
|
}
|
|
s := c.getSubsystem(Freezer)
|
|
if s == nil {
|
|
return Thawed
|
|
}
|
|
sp, err := c.path(Freezer)
|
|
if err != nil {
|
|
return Unknown
|
|
}
|
|
state, err := s.(*freezerController).state(sp)
|
|
if err != nil {
|
|
return Unknown
|
|
}
|
|
return state
|
|
}
|
|
|
|
// MoveTo does a recursive move subsystem by subsystem of all the processes
|
|
// inside the group
|
|
func (c *cgroup) MoveTo(destination Cgroup) error {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.err != nil {
|
|
return c.err
|
|
}
|
|
for _, s := range c.subsystems {
|
|
processes, err := c.processes(s.Name(), true)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
for _, p := range processes {
|
|
if err := destination.Add(p); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *cgroup) getSubsystem(n Name) Subsystem {
|
|
for _, s := range c.subsystems {
|
|
if s.Name() == n {
|
|
return s
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *cgroup) checkExists() {
|
|
for _, s := range pathers(c.subsystems) {
|
|
p, err := c.path(s.Name())
|
|
if err != nil {
|
|
return
|
|
}
|
|
if _, err := os.Lstat(s.Path(p)); err != nil {
|
|
if os.IsNotExist(err) {
|
|
c.err = ErrCgroupDeleted
|
|
return
|
|
}
|
|
}
|
|
}
|
|
}
|