// TODO(vishh): This is part of the libcontainer API and it does much more than just namespaces related work.
// Move this to libcontainer package.
// Exec performs setup outside of a namespace so that a container can be
// executed. Exec is a high level function for working with container namespaces.
func Exec(container *libcontainer.Config, stdin io.Reader, stdout, stderr io.Writer, console string, rootfs, dataPath string, args []string, createCommand CreateCommand, startCallback func()) (int, error) {
var (
err error
)
// create a pipe so that we can syncronize with the namespaced process and
// pass the veth name to the child
syncPipe, err := syncpipe.NewSyncPipe()
if err != nil {
return -1, err
}
defer syncPipe.Close()
command := createCommand(container, console, rootfs, dataPath, os.Args[0], syncPipe.Child(), args)
// Note: these are only used in non-tty mode
// if there is a tty for the container it will be opened within the namespace and the
// fds will be duped to stdin, stdiout, and stderr
command.Stdin = stdin
command.Stdout = stdout
command.Stderr = stderr
if err := command.Start(); err != nil {
return -1, err
}
// Now we passed the pipe to the child, close our side
syncPipe.CloseChild()
started, err := system.GetProcessStartTime(command.Process.Pid)
if err != nil {
return -1, err
}
// Do this before syncing with child so that no children
// can escape the cgroup
cgroupRef, err := SetupCgroups(container, command.Process.Pid)
if err != nil {
command.Process.Kill()
command.Wait()
return -1, err
}
defer cgroupRef.Cleanup()
cgroupPaths, err := cgroupRef.Paths()
if err != nil {
command.Process.Kill()
command.Wait()
return -1, err
}
var networkState network.NetworkState
if err := InitializeNetworking(container, command.Process.Pid, syncPipe, &networkState); err != nil {
command.Process.Kill()
command.Wait()
return -1, err
}
state := &libcontainer.State{
InitPid: command.Process.Pid,
InitStartTime: started,
NetworkState: networkState,
CgroupPaths: cgroupPaths,
}
if err := libcontainer.SaveState(dataPath, state); err != nil {
command.Process.Kill()
command.Wait()
return -1, err
}
defer libcontainer.DeleteState(dataPath)
// Sync with child
if err := syncPipe.ReadFromChild(); err != nil {
command.Process.Kill()
command.Wait()
return -1, err
}
if startCallback != nil {
startCallback()
}
if err := command.Wait(); err != nil {
if _, ok := err.(*exec.ExitError); !ok {
return -1, err
}
}
return command.ProcessState.Sys().(syscall.WaitStatus).ExitStatus(), nil
}
// TODO(vishh): This is part of the libcontainer API and it does much more than just namespaces related work.
// Move this to libcontainer package.
// Exec performs setup outside of a namespace so that a container can be
// executed. Exec is a high level function for working with container namespaces.
func Exec(container *libcontainer.Config, term Terminal, rootfs, dataPath string, args []string, createCommand CreateCommand, startCallback func()) (int, error) {
var (
master *os.File
console string
err error
)
// create a pipe so that we can syncronize with the namespaced process and
// pass the veth name to the child
syncPipe, err := syncpipe.NewSyncPipe()
if err != nil {
return -1, err
}
defer syncPipe.Close()
if container.Tty {
master, console, err = system.CreateMasterAndConsole()
if err != nil {
return -1, err
}
term.SetMaster(master)
}
command := createCommand(container, console, rootfs, dataPath, os.Args[0], syncPipe.Child(), args)
if err := term.Attach(command); err != nil {
return -1, err
}
defer term.Close()
if err := command.Start(); err != nil {
return -1, err
}
// Now we passed the pipe to the child, close our side
syncPipe.CloseChild()
started, err := system.GetProcessStartTime(command.Process.Pid)
if err != nil {
return -1, err
}
// Do this before syncing with child so that no children
// can escape the cgroup
cleaner, err := SetupCgroups(container, command.Process.Pid)
if err != nil {
command.Process.Kill()
command.Wait()
return -1, err
}
if cleaner != nil {
defer cleaner.Cleanup()
}
var networkState network.NetworkState
if err := InitializeNetworking(container, command.Process.Pid, syncPipe, &networkState); err != nil {
command.Process.Kill()
command.Wait()
return -1, err
}
state := &libcontainer.State{
InitPid: command.Process.Pid,
InitStartTime: started,
NetworkState: networkState,
}
if err := libcontainer.SaveState(dataPath, state); err != nil {
command.Process.Kill()
command.Wait()
return -1, err
}
defer libcontainer.DeleteState(dataPath)
// Sync with child
if err := syncPipe.ReadFromChild(); err != nil {
command.Process.Kill()
command.Wait()
return -1, err
}
if startCallback != nil {
startCallback()
}
if err := command.Wait(); err != nil {
if _, ok := err.(*exec.ExitError); !ok {
return -1, err
}
}
return command.ProcessState.Sys().(syscall.WaitStatus).ExitStatus(), nil
}
// TODO(vishh): This is part of the libcontainer API and it does much more than just namespaces related work.
// Move this to libcontainer package.
// Exec performs setup outside of a namespace so that a container can be
// executed. Exec is a high level function for working with container namespaces.
func Exec(container *libcontainer.Config, stdin io.Reader, stdout, stderr io.Writer, console, dataPath string, args []string, createCommand CreateCommand, startCallback func()) (int, error) {
var err error
// create a pipe so that we can syncronize with the namespaced process and
// pass the state and configuration to the child process
parent, child, err := newInitPipe()
if err != nil {
return -1, err
}
defer parent.Close()
command := createCommand(container, console, dataPath, os.Args[0], child, args)
// Note: these are only used in non-tty mode
// if there is a tty for the container it will be opened within the namespace and the
// fds will be duped to stdin, stdiout, and stderr
command.Stdin = stdin
command.Stdout = stdout
command.Stderr = stderr
if err := command.Start(); err != nil {
child.Close()
return -1, err
}
child.Close()
wait := func() (*os.ProcessState, error) {
ps, err := command.Process.Wait()
// we should kill all processes in cgroup when init is died if we use
// host PID namespace
if !container.Namespaces.Contains(libcontainer.NEWPID) {
killAllPids(container)
}
return ps, err
}
terminate := func(terr error) (int, error) {
// TODO: log the errors for kill and wait
command.Process.Kill()
wait()
return -1, terr
}
started, err := system.GetProcessStartTime(command.Process.Pid)
if err != nil {
return terminate(err)
}
// Do this before syncing with child so that no children
// can escape the cgroup
cgroupPaths, err := SetupCgroups(container, command.Process.Pid)
if err != nil {
return terminate(err)
}
defer cgroups.RemovePaths(cgroupPaths)
var networkState network.NetworkState
if err := InitializeNetworking(container, command.Process.Pid, &networkState); err != nil {
return terminate(err)
}
// send the state to the container's init process then shutdown writes for the parent
if err := json.NewEncoder(parent).Encode(networkState); err != nil {
return terminate(err)
}
// shutdown writes for the parent side of the pipe
if err := syscall.Shutdown(int(parent.Fd()), syscall.SHUT_WR); err != nil {
return terminate(err)
}
state := &libcontainer.State{
InitPid: command.Process.Pid,
InitStartTime: started,
NetworkState: networkState,
CgroupPaths: cgroupPaths,
}
if err := libcontainer.SaveState(dataPath, state); err != nil {
return terminate(err)
}
defer libcontainer.DeleteState(dataPath)
// wait for the child process to fully complete and receive an error message
// if one was encoutered
var ierr *initError
if err := json.NewDecoder(parent).Decode(&ierr); err != nil && err != io.EOF {
return terminate(err)
}
if ierr != nil {
return terminate(ierr)
}
if startCallback != nil {
startCallback()
}
ps, err := wait()
if err != nil {
if _, ok := err.(*exec.ExitError); !ok {
return -1, err
}
}
// waiting for pipe flushing
command.Wait()
waitStatus := ps.Sys().(syscall.WaitStatus)
if waitStatus.Signaled() {
return EXIT_SIGNAL_OFFSET + int(waitStatus.Signal()), nil
}
return waitStatus.ExitStatus(), nil
}