281 lines
7.2 KiB
Go
281 lines
7.2 KiB
Go
// +build linux
|
|
|
|
package libcontainer
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"os/exec"
|
|
"syscall"
|
|
|
|
"github.com/docker/libcontainer/cgroups"
|
|
"github.com/docker/libcontainer/configs"
|
|
"github.com/golang/glog"
|
|
)
|
|
|
|
type linuxContainer struct {
|
|
id string
|
|
root string
|
|
config *configs.Config
|
|
cgroupManager cgroups.Manager
|
|
initArgs []string
|
|
initProcess parentProcess
|
|
}
|
|
|
|
// ID returns the container's unique ID
|
|
func (c *linuxContainer) ID() string {
|
|
return c.id
|
|
}
|
|
|
|
// Config returns the container's configuration
|
|
func (c *linuxContainer) Config() configs.Config {
|
|
return *c.config
|
|
}
|
|
|
|
func (c *linuxContainer) Status() (configs.Status, error) {
|
|
if c.initProcess == nil {
|
|
return configs.Destroyed, nil
|
|
}
|
|
// return Running if the init process is alive
|
|
if err := syscall.Kill(c.initProcess.pid(), 0); err != nil {
|
|
if err == syscall.ESRCH {
|
|
return configs.Destroyed, nil
|
|
}
|
|
return 0, err
|
|
}
|
|
if c.config.Cgroups != nil && c.config.Cgroups.Freezer == configs.Frozen {
|
|
return configs.Paused, nil
|
|
}
|
|
return configs.Running, nil
|
|
}
|
|
|
|
func (c *linuxContainer) State() (*State, error) {
|
|
status, err := c.Status()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if status == configs.Destroyed {
|
|
return nil, newGenericError(fmt.Errorf("container destroyed"), ContainerNotExists)
|
|
}
|
|
startTime, err := c.initProcess.startTime()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
state := &State{
|
|
InitProcessPid: c.initProcess.pid(),
|
|
InitProcessStartTime: startTime,
|
|
CgroupPaths: c.cgroupManager.GetPaths(),
|
|
NamespacePaths: make(map[string]string),
|
|
}
|
|
for _, ns := range c.config.Namespaces {
|
|
if ns.Path != "" {
|
|
state.NamespacePaths[string(ns.Type)] = ns.Path
|
|
continue
|
|
}
|
|
file := ""
|
|
switch ns.Type {
|
|
case configs.NEWNET:
|
|
file = "net"
|
|
case configs.NEWNS:
|
|
file = "mnt"
|
|
case configs.NEWPID:
|
|
file = "pid"
|
|
case configs.NEWIPC:
|
|
file = "ipc"
|
|
case configs.NEWUSER:
|
|
file = "user"
|
|
case configs.NEWUTS:
|
|
file = "uts"
|
|
}
|
|
state.NamespacePaths[string(ns.Type)] = fmt.Sprintf("/proc/%d/ns/%s", c.initProcess.pid(), file)
|
|
}
|
|
return state, nil
|
|
}
|
|
|
|
func (c *linuxContainer) Processes() ([]int, error) {
|
|
glog.Info("fetch container processes")
|
|
pids, err := c.cgroupManager.GetPids()
|
|
if err != nil {
|
|
return nil, newGenericError(err, SystemError)
|
|
}
|
|
return pids, nil
|
|
}
|
|
|
|
func (c *linuxContainer) Stats() (*Stats, error) {
|
|
glog.Info("fetch container stats")
|
|
var (
|
|
err error
|
|
stats = &Stats{}
|
|
)
|
|
if stats.CgroupStats, err = c.cgroupManager.GetStats(); err != nil {
|
|
return stats, newGenericError(err, SystemError)
|
|
}
|
|
for _, iface := range c.config.Networks {
|
|
switch iface.Type {
|
|
case "veth":
|
|
istats, err := getNetworkInterfaceStats(iface.HostInterfaceName)
|
|
if err != nil {
|
|
return stats, newGenericError(err, SystemError)
|
|
}
|
|
stats.Interfaces = append(stats.Interfaces, istats)
|
|
}
|
|
}
|
|
return stats, nil
|
|
}
|
|
|
|
func (c *linuxContainer) Start(process *Process) (int, error) {
|
|
status, err := c.Status()
|
|
if err != nil {
|
|
return -1, err
|
|
}
|
|
doInit := status == configs.Destroyed
|
|
parent, err := c.newParentProcess(process, doInit)
|
|
if err != nil {
|
|
return -1, err
|
|
}
|
|
if err := parent.start(); err != nil {
|
|
// terminate the process to ensure that it properly is reaped.
|
|
if err := parent.terminate(); err != nil {
|
|
glog.Warning(err)
|
|
}
|
|
return -1, err
|
|
}
|
|
if doInit {
|
|
c.initProcess = parent
|
|
}
|
|
return parent.pid(), nil
|
|
}
|
|
|
|
func (c *linuxContainer) newParentProcess(p *Process, doInit bool) (parentProcess, error) {
|
|
parentPipe, childPipe, err := newPipe()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
cmd, err := c.commandTemplate(p, childPipe)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if !doInit {
|
|
return c.newSetnsProcess(p, cmd, parentPipe, childPipe), nil
|
|
}
|
|
return c.newInitProcess(p, cmd, parentPipe, childPipe), nil
|
|
}
|
|
|
|
func (c *linuxContainer) commandTemplate(p *Process, childPipe *os.File) (*exec.Cmd, error) {
|
|
cmd := exec.Command(c.initArgs[0], c.initArgs[1:]...)
|
|
cmd.Stdin = p.Stdin
|
|
cmd.Stdout = p.Stdout
|
|
cmd.Stderr = p.Stderr
|
|
cmd.Dir = c.config.Rootfs
|
|
if cmd.SysProcAttr == nil {
|
|
cmd.SysProcAttr = &syscall.SysProcAttr{}
|
|
}
|
|
cmd.ExtraFiles = []*os.File{childPipe}
|
|
cmd.SysProcAttr.Pdeathsig = syscall.Signal(c.config.ParentDeathSignal)
|
|
return cmd, nil
|
|
}
|
|
|
|
func (c *linuxContainer) newInitProcess(p *Process, cmd *exec.Cmd, parentPipe, childPipe *os.File) *initProcess {
|
|
t := "_LIBCONTAINER_INITTYPE=standard"
|
|
|
|
cloneFlags := c.config.Namespaces.CloneFlags()
|
|
if cloneFlags&syscall.CLONE_NEWUSER != 0 {
|
|
c.addUidGidMappings(cmd.SysProcAttr)
|
|
// Default to root user when user namespaces are enabled.
|
|
if cmd.SysProcAttr.Credential == nil {
|
|
cmd.SysProcAttr.Credential = &syscall.Credential{}
|
|
}
|
|
t = "_LIBCONTAINER_INITTYPE=userns"
|
|
}
|
|
cmd.Env = append(cmd.Env, t)
|
|
cmd.SysProcAttr.Cloneflags = cloneFlags
|
|
return &initProcess{
|
|
cmd: cmd,
|
|
childPipe: childPipe,
|
|
parentPipe: parentPipe,
|
|
manager: c.cgroupManager,
|
|
config: c.newInitConfig(p),
|
|
}
|
|
}
|
|
|
|
func (c *linuxContainer) newSetnsProcess(p *Process, cmd *exec.Cmd, parentPipe, childPipe *os.File) *setnsProcess {
|
|
cmd.Env = append(cmd.Env,
|
|
fmt.Sprintf("_LIBCONTAINER_INITPID=%d", c.initProcess.pid()),
|
|
"_LIBCONTAINER_INITTYPE=setns",
|
|
)
|
|
// TODO: set on container for process management
|
|
return &setnsProcess{
|
|
cmd: cmd,
|
|
cgroupPaths: c.cgroupManager.GetPaths(),
|
|
childPipe: childPipe,
|
|
parentPipe: parentPipe,
|
|
config: c.newInitConfig(p),
|
|
}
|
|
}
|
|
|
|
func (c *linuxContainer) newInitConfig(process *Process) *initConfig {
|
|
return &initConfig{
|
|
Config: c.config,
|
|
Args: process.Args,
|
|
Env: process.Env,
|
|
}
|
|
}
|
|
|
|
// Converts IDMap to SysProcIDMap array and adds it to SysProcAttr.
|
|
func (c *linuxContainer) addUidGidMappings(sys *syscall.SysProcAttr) {
|
|
if c.config.UidMappings != nil {
|
|
sys.UidMappings = make([]syscall.SysProcIDMap, len(c.config.UidMappings))
|
|
for i, um := range c.config.UidMappings {
|
|
sys.UidMappings[i].ContainerID = um.ContainerID
|
|
sys.UidMappings[i].HostID = um.HostID
|
|
sys.UidMappings[i].Size = um.Size
|
|
}
|
|
}
|
|
if c.config.GidMappings != nil {
|
|
sys.GidMappings = make([]syscall.SysProcIDMap, len(c.config.GidMappings))
|
|
for i, gm := range c.config.GidMappings {
|
|
sys.GidMappings[i].ContainerID = gm.ContainerID
|
|
sys.GidMappings[i].HostID = gm.HostID
|
|
sys.GidMappings[i].Size = gm.Size
|
|
}
|
|
}
|
|
}
|
|
|
|
func newPipe() (parent *os.File, child *os.File, err error) {
|
|
fds, err := syscall.Socketpair(syscall.AF_LOCAL, syscall.SOCK_STREAM|syscall.SOCK_CLOEXEC, 0)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
return os.NewFile(uintptr(fds[1]), "parent"), os.NewFile(uintptr(fds[0]), "child"), nil
|
|
}
|
|
|
|
func (c *linuxContainer) Destroy() error {
|
|
status, err := c.Status()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if status != configs.Destroyed {
|
|
return newGenericError(nil, ContainerNotStopped)
|
|
}
|
|
// TODO: remove cgroups
|
|
return os.RemoveAll(c.root)
|
|
}
|
|
|
|
func (c *linuxContainer) Pause() error {
|
|
return c.cgroupManager.Freeze(configs.Frozen)
|
|
}
|
|
|
|
func (c *linuxContainer) Resume() error {
|
|
return c.cgroupManager.Freeze(configs.Thawed)
|
|
}
|
|
|
|
func (c *linuxContainer) Signal(signal os.Signal) error {
|
|
glog.Infof("sending signal %d to pid %d", signal, c.initProcess.pid())
|
|
return c.initProcess.signal(signal)
|
|
}
|
|
|
|
// TODO: rename to be more descriptive
|
|
func (c *linuxContainer) OOM() (<-chan struct{}, error) {
|
|
return NotifyOnOOM(c.cgroupManager.GetPaths())
|
|
}
|