func execProcess(context *cli.Context) (int, error) {
container, err := getContainer(context)
if err != nil {
return -1, err
}
path := context.String("process")
if path == "" && len(context.Args()) == 1 {
return -1, fmt.Errorf("process args cannot be empty")
}
detach := context.Bool("detach")
state, err := container.State()
if err != nil {
return -1, err
}
bundle := utils.SearchLabels(state.Config.Labels, "bundle")
p, err := getProcess(context, bundle)
if err != nil {
return -1, err
}
r := &runner{
enableSubreaper: !context.Bool("no-subreaper"),
shouldDestroy: false,
container: container,
console: context.String("console"),
detach: detach,
pidFile: context.String("pid-file"),
}
return r.run(p)
}
func (c *linuxContainer) Start(process *Process) error {
c.m.Lock()
defer c.m.Unlock()
status, err := c.currentStatus()
if err != nil {
return err
}
doInit := status == Destroyed
parent, err := c.newParentProcess(process, doInit)
if err != nil {
return newSystemErrorWithCause(err, "creating new parent process")
}
if err := parent.start(); err != nil {
// terminate the process to ensure that it properly is reaped.
if err := parent.terminate(); err != nil {
logrus.Warn(err)
}
return newSystemErrorWithCause(err, "starting container process")
}
// generate a timestamp indicating when the container was started
c.created = time.Now().UTC()
c.state = &runningState{
c: c,
}
if doInit {
if err := c.updateState(parent); err != nil {
return err
}
if c.config.Hooks != nil {
s := configs.HookState{
Version: c.config.Version,
ID: c.id,
Pid: parent.pid(),
Root: c.config.Rootfs,
BundlePath: utils.SearchLabels(c.config.Labels, "bundle"),
}
for i, hook := range c.config.Hooks.Poststart {
if err := hook.Run(s); err != nil {
if err := parent.terminate(); err != nil {
logrus.Warn(err)
}
return newSystemErrorWithCausef(err, "running poststart hook %d", i)
}
}
}
}
return nil
}
func runPoststopHooks(c *linuxContainer) error {
if c.config.Hooks != nil {
s := configs.HookState{
Version: c.config.Version,
ID: c.id,
Root: c.config.Rootfs,
BundlePath: utils.SearchLabels(c.config.Labels, "bundle"),
}
for _, hook := range c.config.Hooks.Poststop {
if err := hook.Run(s); err != nil {
return err
}
}
}
return nil
}
func getContainers(context *cli.Context) ([]containerState, error) {
factory, err := loadFactory(context)
if err != nil {
return nil, err
}
root := context.GlobalString("root")
absRoot, err := filepath.Abs(root)
if err != nil {
return nil, err
}
list, err := ioutil.ReadDir(absRoot)
if err != nil {
fatal(err)
}
var s []containerState
for _, item := range list {
if item.IsDir() {
container, err := factory.Load(item.Name())
if err != nil {
return nil, err
}
containerStatus, err := container.Status()
if err != nil {
return nil, err
}
state, err := container.State()
if err != nil {
return nil, err
}
s = append(s, containerState{
ID: state.BaseState.ID,
InitProcessPid: state.BaseState.InitProcessPid,
Status: containerStatus.String(),
Bundle: utils.SearchLabels(state.Config.Labels, "bundle"),
Created: state.BaseState.Created})
}
}
return s, nil
}
func (p *initProcess) start() error {
defer p.parentPipe.Close()
err := p.cmd.Start()
p.process.ops = p
p.childPipe.Close()
p.rootDir.Close()
if err != nil {
p.process.ops = nil
return newSystemErrorWithCause(err, "starting init process command")
}
if _, err := io.Copy(p.parentPipe, p.bootstrapData); err != nil {
return err
}
if err := p.execSetns(); err != nil {
return newSystemErrorWithCause(err, "running exec setns process for init")
}
// Save the standard descriptor names before the container process
// can potentially move them (e.g., via dup2()). If we don't do this now,
// we won't know at checkpoint time which file descriptor to look up.
fds, err := getPipeFds(p.pid())
if err != nil {
return newSystemErrorWithCausef(err, "getting pipe fds for pid %d", p.pid())
}
p.setExternalDescriptors(fds)
// Do this before syncing with child so that no children
// can escape the cgroup
if err := p.manager.Apply(p.pid()); err != nil {
return newSystemErrorWithCause(err, "applying cgroup configuration for process")
}
defer func() {
if err != nil {
// TODO: should not be the responsibility to call here
p.manager.Destroy()
}
}()
if err := p.createNetworkInterfaces(); err != nil {
return newSystemErrorWithCause(err, "creating nework interfaces")
}
if err := p.sendConfig(); err != nil {
return newSystemErrorWithCause(err, "sending config to init process")
}
var (
procSync syncT
sentRun bool
sentResume bool
ierr *genericError
)
dec := json.NewDecoder(p.parentPipe)
loop:
for {
if err := dec.Decode(&procSync); err != nil {
if err == io.EOF {
break loop
}
return newSystemErrorWithCause(err, "decoding sync type from init pipe")
}
switch procSync.Type {
case procReady:
if err := p.manager.Set(p.config.Config); err != nil {
return newSystemErrorWithCause(err, "setting cgroup config for ready process")
}
// set oom_score_adj
if err := setOomScoreAdj(p.config.Config.OomScoreAdj, p.pid()); err != nil {
return newSystemErrorWithCause(err, "setting oom score for ready process")
}
// 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 ready process")
}
// call prestart hooks
if !p.config.Config.Namespaces.Contains(configs.NEWNS) {
if p.config.Config.Hooks != nil {
s := configs.HookState{
Version: p.container.config.Version,
ID: p.container.id,
Pid: p.pid(),
Root: p.config.Config.Rootfs,
}
for i, hook := range p.config.Config.Hooks.Prestart {
if err := hook.Run(s); err != nil {
return newSystemErrorWithCausef(err, "running prestart hook %d", i)
}
}
}
}
// Sync with child.
if err := utils.WriteJSON(p.parentPipe, syncT{procRun}); err != nil {
return newSystemErrorWithCause(err, "reading syncT run type")
}
sentRun = true
case procHooks:
if p.config.Config.Hooks != nil {
s := configs.HookState{
Version: p.container.config.Version,
ID: p.container.id,
Pid: p.pid(),
Root: p.config.Config.Rootfs,
BundlePath: utils.SearchLabels(p.config.Config.Labels, "bundle"),
}
for i, hook := range p.config.Config.Hooks.Prestart {
if err := hook.Run(s); err != nil {
return newSystemErrorWithCausef(err, "running prestart hook %d", i)
}
}
}
// Sync with child.
if err := utils.WriteJSON(p.parentPipe, syncT{procResume}); err != nil {
return newSystemErrorWithCause(err, "reading syncT resume type")
}
sentResume = true
case procError:
// wait for the child process to fully complete and receive an error message
// if one was encoutered
if err := dec.Decode(&ierr); err != nil && err != io.EOF {
return newSystemErrorWithCause(err, "decoding proc error from init")
}
if ierr != nil {
break loop
}
// Programmer error.
panic("No error following JSON procError payload.")
default:
return newSystemError(fmt.Errorf("invalid JSON payload from child"))
}
}
if !sentRun {
return newSystemErrorWithCause(ierr, "container init")
}
if p.config.Config.Namespaces.Contains(configs.NEWNS) && !sentResume {
return newSystemError(fmt.Errorf("could not synchronise after executing prestart hooks with container process"))
}
if err := syscall.Shutdown(int(p.parentPipe.Fd()), syscall.SHUT_WR); err != nil {
return newSystemErrorWithCause(err, "shutting down 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
}
instance of a container.`,
Action: func(context *cli.Context) error {
container, err := getContainer(context)
if err != nil {
return err
}
containerStatus, err := container.Status()
if err != nil {
return err
}
state, err := container.State()
if err != nil {
return err
}
cs := cState{
Version: state.BaseState.Config.Version,
ID: state.BaseState.ID,
InitProcessPid: state.BaseState.InitProcessPid,
Status: containerStatus.String(),
Bundle: utils.SearchLabels(state.Config.Labels, "bundle"),
Rootfs: state.BaseState.Config.Rootfs,
Created: state.BaseState.Created}
data, err := json.MarshalIndent(cs, "", " ")
if err != nil {
return err
}
os.Stdout.Write(data)
return nil
},
}
func (p *initProcess) start() error {
defer p.parentPipe.Close()
err := p.cmd.Start()
p.process.ops = p
p.childPipe.Close()
p.rootDir.Close()
if err != nil {
p.process.ops = nil
return newSystemErrorWithCause(err, "starting init process command")
}
if _, err := io.Copy(p.parentPipe, p.bootstrapData); err != nil {
return err
}
if err := p.execSetns(); err != nil {
return newSystemErrorWithCause(err, "running exec setns process for init")
}
// Save the standard descriptor names before the container process
// can potentially move them (e.g., via dup2()). If we don't do this now,
// we won't know at checkpoint time which file descriptor to look up.
fds, err := getPipeFds(p.pid())
if err != nil {
return newSystemErrorWithCausef(err, "getting pipe fds for pid %d", p.pid())
}
p.setExternalDescriptors(fds)
// Do this before syncing with child so that no children
// can escape the cgroup
if err := p.manager.Apply(p.pid()); err != nil {
return newSystemErrorWithCause(err, "applying cgroup configuration for process")
}
defer func() {
if err != nil {
// TODO: should not be the responsibility to call here
p.manager.Destroy()
}
}()
if err := p.createNetworkInterfaces(); err != nil {
return newSystemErrorWithCause(err, "creating network interfaces")
}
if err := p.sendConfig(); err != nil {
return newSystemErrorWithCause(err, "sending config to init process")
}
var (
sentRun bool
sentResume bool
)
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:
if err := p.manager.Set(p.config.Config); err != nil {
return newSystemErrorWithCause(err, "setting cgroup config for ready process")
}
// set oom_score_adj
if err := setOomScoreAdj(p.config.Config.OomScoreAdj, p.pid()); err != nil {
return newSystemErrorWithCause(err, "setting oom score for ready process")
}
// 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 ready process")
}
// call prestart hooks
if !p.config.Config.Namespaces.Contains(configs.NEWNS) {
if p.config.Config.Hooks != nil {
s := configs.HookState{
Version: p.container.config.Version,
ID: p.container.id,
Pid: p.pid(),
Root: p.config.Config.Rootfs,
}
for i, hook := range p.config.Config.Hooks.Prestart {
if err := hook.Run(s); err != nil {
return newSystemErrorWithCausef(err, "running prestart hook %d", i)
}
}
}
}
// Sync with child.
if err := writeSync(p.parentPipe, procRun); err != nil {
return newSystemErrorWithCause(err, "writing syncT 'run'")
}
sentRun = true
case procHooks:
if p.config.Config.Hooks != nil {
s := configs.HookState{
Version: p.container.config.Version,
ID: p.container.id,
Pid: p.pid(),
Root: p.config.Config.Rootfs,
BundlePath: utils.SearchLabels(p.config.Config.Labels, "bundle"),
}
for i, hook := range p.config.Config.Hooks.Prestart {
if err := hook.Run(s); err != nil {
return newSystemErrorWithCausef(err, "running prestart hook %d", i)
}
}
}
// Sync with child.
if err := writeSync(p.parentPipe, procResume); err != nil {
return newSystemErrorWithCause(err, "writing syncT 'resume'")
}
sentResume = true
default:
return newSystemError(fmt.Errorf("invalid JSON payload from child"))
}
return nil
})
if !sentRun {
return newSystemErrorWithCause(ierr, "container init")
}
if p.config.Config.Namespaces.Contains(configs.NEWNS) && !sentResume {
return newSystemError(fmt.Errorf("could not synchronise after executing prestart hooks with container process"))
}
if err := syscall.Shutdown(int(p.parentPipe.Fd()), syscall.SHUT_WR); err != nil {
return newSystemErrorWithCause(err, "shutting down 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
}