Switch to golang/dep.

vendor/github.com/opencontainers/runc/libcontainer/factory_linux.go

@@ -0,0 +1,337 @@
+// +build linux
+
+package libcontainer
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"runtime/debug"
+	"strconv"
+	"syscall"
+
+	"github.com/docker/docker/pkg/mount"
+	"github.com/opencontainers/runc/libcontainer/cgroups"
+	"github.com/opencontainers/runc/libcontainer/cgroups/fs"
+	"github.com/opencontainers/runc/libcontainer/cgroups/rootless"
+	"github.com/opencontainers/runc/libcontainer/cgroups/systemd"
+	"github.com/opencontainers/runc/libcontainer/configs"
+	"github.com/opencontainers/runc/libcontainer/configs/validate"
+	"github.com/opencontainers/runc/libcontainer/utils"
+)
+
+const (
+	stateFilename    = "state.json"
+	execFifoFilename = "exec.fifo"
+)
+
+var (
+	idRegex  = regexp.MustCompile(`^[\w+-\.]+$`)
+	maxIdLen = 1024
+)
+
+// InitArgs returns an options func to configure a LinuxFactory with the
+// provided init binary path and arguments.
+func InitArgs(args ...string) func(*LinuxFactory) error {
+	return func(l *LinuxFactory) (err error) {
+		if len(args) > 0 {
+			// Resolve relative paths to ensure that its available
+			// after directory changes.
+			if args[0], err = filepath.Abs(args[0]); err != nil {
+				return newGenericError(err, ConfigInvalid)
+			}
+		}
+
+		l.InitArgs = args
+		return nil
+	}
+}
+
+// SystemdCgroups is an options func to configure a LinuxFactory to return
+// containers that use systemd to create and manage cgroups.
+func SystemdCgroups(l *LinuxFactory) error {
+	l.NewCgroupsManager = func(config *configs.Cgroup, paths map[string]string) cgroups.Manager {
+		return &systemd.Manager{
+			Cgroups: config,
+			Paths:   paths,
+		}
+	}
+	return nil
+}
+
+// Cgroupfs is an options func to configure a LinuxFactory to return
+// containers that use the native cgroups filesystem implementation to
+// create and manage cgroups.
+func Cgroupfs(l *LinuxFactory) error {
+	l.NewCgroupsManager = func(config *configs.Cgroup, paths map[string]string) cgroups.Manager {
+		return &fs.Manager{
+			Cgroups: config,
+			Paths:   paths,
+		}
+	}
+	return nil
+}
+
+// RootlessCgroups is an options func to configure a LinuxFactory to
+// return containers that use the "rootless" cgroup manager, which will
+// fail to do any operations not possible to do with an unprivileged user.
+// It should only be used in conjunction with rootless containers.
+func RootlessCgroups(l *LinuxFactory) error {
+	l.NewCgroupsManager = func(config *configs.Cgroup, paths map[string]string) cgroups.Manager {
+		return &rootless.Manager{
+			Cgroups: config,
+			Paths:   paths,
+		}
+	}
+	return nil
+}
+
+// TmpfsRoot is an option func to mount LinuxFactory.Root to tmpfs.
+func TmpfsRoot(l *LinuxFactory) error {
+	mounted, err := mount.Mounted(l.Root)
+	if err != nil {
+		return err
+	}
+	if !mounted {
+		if err := syscall.Mount("tmpfs", l.Root, "tmpfs", 0, ""); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// CriuPath returns an option func to configure a LinuxFactory with the
+// provided criupath
+func CriuPath(criupath string) func(*LinuxFactory) error {
+	return func(l *LinuxFactory) error {
+		l.CriuPath = criupath
+		return nil
+	}
+}
+
+// New returns a linux based container factory based in the root directory and
+// configures the factory with the provided option funcs.
+func New(root string, options ...func(*LinuxFactory) error) (Factory, error) {
+	if root != "" {
+		if err := os.MkdirAll(root, 0700); err != nil {
+			return nil, newGenericError(err, SystemError)
+		}
+	}
+	l := &LinuxFactory{
+		Root:      root,
+		InitArgs:  []string{"/proc/self/exe", "init"},
+		Validator: validate.New(),
+		CriuPath:  "criu",
+	}
+	Cgroupfs(l)
+	for _, opt := range options {
+		if err := opt(l); err != nil {
+			return nil, err
+		}
+	}
+	return l, nil
+}
+
+// LinuxFactory implements the default factory interface for linux based systems.
+type LinuxFactory struct {
+	// Root directory for the factory to store state.
+	Root string
+
+	// InitArgs are arguments for calling the init responsibilities for spawning
+	// a container.
+	InitArgs []string
+
+	// CriuPath is the path to the criu binary used for checkpoint and restore of
+	// containers.
+	CriuPath string
+
+	// Validator provides validation to container configurations.
+	Validator validate.Validator
+
+	// NewCgroupsManager returns an initialized cgroups manager for a single container.
+	NewCgroupsManager func(config *configs.Cgroup, paths map[string]string) cgroups.Manager
+}
+
+func (l *LinuxFactory) Create(id string, config *configs.Config) (Container, error) {
+	if l.Root == "" {
+		return nil, newGenericError(fmt.Errorf("invalid root"), ConfigInvalid)
+	}
+	if err := l.validateID(id); err != nil {
+		return nil, err
+	}
+	if err := l.Validator.Validate(config); err != nil {
+		return nil, newGenericError(err, ConfigInvalid)
+	}
+	uid, err := config.HostRootUID()
+	if err != nil {
+		return nil, newGenericError(err, SystemError)
+	}
+	gid, err := config.HostRootGID()
+	if err != nil {
+		return nil, newGenericError(err, SystemError)
+	}
+	containerRoot := filepath.Join(l.Root, id)
+	if _, err := os.Stat(containerRoot); err == nil {
+		return nil, newGenericError(fmt.Errorf("container with id exists: %v", id), IdInUse)
+	} else if !os.IsNotExist(err) {
+		return nil, newGenericError(err, SystemError)
+	}
+	if err := os.MkdirAll(containerRoot, 0711); err != nil {
+		return nil, newGenericError(err, SystemError)
+	}
+	if err := os.Chown(containerRoot, uid, gid); err != nil {
+		return nil, newGenericError(err, SystemError)
+	}
+	if config.Rootless {
+		RootlessCgroups(l)
+	}
+	c := &linuxContainer{
+		id:            id,
+		root:          containerRoot,
+		config:        config,
+		initArgs:      l.InitArgs,
+		criuPath:      l.CriuPath,
+		cgroupManager: l.NewCgroupsManager(config.Cgroups, nil),
+	}
+	c.state = &stoppedState{c: c}
+	return c, nil
+}
+
+func (l *LinuxFactory) Load(id string) (Container, error) {
+	if l.Root == "" {
+		return nil, newGenericError(fmt.Errorf("invalid root"), ConfigInvalid)
+	}
+	containerRoot := filepath.Join(l.Root, id)
+	state, err := l.loadState(containerRoot, id)
+	if err != nil {
+		return nil, err
+	}
+	r := &nonChildProcess{
+		processPid:       state.InitProcessPid,
+		processStartTime: state.InitProcessStartTime,
+		fds:              state.ExternalDescriptors,
+	}
+	// We have to use the RootlessManager.
+	if state.Rootless {
+		RootlessCgroups(l)
+	}
+	c := &linuxContainer{
+		initProcess:          r,
+		initProcessStartTime: state.InitProcessStartTime,
+		id:                   id,
+		config:               &state.Config,
+		initArgs:             l.InitArgs,
+		criuPath:             l.CriuPath,
+		cgroupManager:        l.NewCgroupsManager(state.Config.Cgroups, state.CgroupPaths),
+		root:                 containerRoot,
+		created:              state.Created,
+	}
+	c.state = &loadedState{c: c}
+	if err := c.refreshState(); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+func (l *LinuxFactory) Type() string {
+	return "libcontainer"
+}
+
+// StartInitialization loads a container by opening the pipe fd from the parent to read the configuration and state
+// This is a low level implementation detail of the reexec and should not be consumed externally
+func (l *LinuxFactory) StartInitialization() (err error) {
+	var (
+		pipefd, rootfd int
+		consoleSocket  *os.File
+		envInitPipe    = os.Getenv("_LIBCONTAINER_INITPIPE")
+		envStateDir    = os.Getenv("_LIBCONTAINER_STATEDIR")
+		envConsole     = os.Getenv("_LIBCONTAINER_CONSOLE")
+	)
+
+	// Get the INITPIPE.
+	pipefd, err = strconv.Atoi(envInitPipe)
+	if err != nil {
+		return fmt.Errorf("unable to convert _LIBCONTAINER_INITPIPE=%s to int: %s", envInitPipe, err)
+	}
+
+	var (
+		pipe = os.NewFile(uintptr(pipefd), "pipe")
+		it   = initType(os.Getenv("_LIBCONTAINER_INITTYPE"))
+	)
+	defer pipe.Close()
+
+	// Only init processes have STATEDIR.
+	rootfd = -1
+	if it == initStandard {
+		if rootfd, err = strconv.Atoi(envStateDir); err != nil {
+			return fmt.Errorf("unable to convert _LIBCONTAINER_STATEDIR=%s to int: %s", envStateDir, err)
+		}
+	}
+
+	if envConsole != "" {
+		console, err := strconv.Atoi(envConsole)
+		if err != nil {
+			return fmt.Errorf("unable to convert _LIBCONTAINER_CONSOLE=%s to int: %s", envConsole, err)
+		}
+		consoleSocket = os.NewFile(uintptr(console), "console-socket")
+		defer consoleSocket.Close()
+	}
+
+	// clear the current process's environment to clean any libcontainer
+	// specific env vars.
+	os.Clearenv()
+
+	defer func() {
+		// We have an error during the initialization of the container's init,
+		// send it back to the parent process in the form of an initError.
+		if werr := utils.WriteJSON(pipe, syncT{procError}); werr != nil {
+			fmt.Fprintln(os.Stderr, err)
+			return
+		}
+		if werr := utils.WriteJSON(pipe, newSystemError(err)); werr != nil {
+			fmt.Fprintln(os.Stderr, err)
+			return
+		}
+	}()
+	defer func() {
+		if e := recover(); e != nil {
+			err = fmt.Errorf("panic from initialization: %v, %v", e, string(debug.Stack()))
+		}
+	}()
+
+	i, err := newContainerInit(it, pipe, consoleSocket, rootfd)
+	if err != nil {
+		return err
+	}
+
+	// If Init succeeds, syscall.Exec will not return, hence none of the defers will be called.
+	return i.Init()
+}
+
+func (l *LinuxFactory) loadState(root, id string) (*State, error) {
+	f, err := os.Open(filepath.Join(root, stateFilename))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, newGenericError(fmt.Errorf("container %q does not exist", id), ContainerNotExists)
+		}
+		return nil, newGenericError(err, SystemError)
+	}
+	defer f.Close()
+	var state *State
+	if err := json.NewDecoder(f).Decode(&state); err != nil {
+		return nil, newGenericError(err, SystemError)
+	}
+	return state, nil
+}
+
+func (l *LinuxFactory) validateID(id string) error {
+	if !idRegex.MatchString(id) {
+		return newGenericError(fmt.Errorf("invalid id format: %v", id), InvalidIdFormat)
+	}
+	if len(id) > maxIdLen {
+		return newGenericError(fmt.Errorf("invalid id format: %v", id), InvalidIdFormat)
+	}
+	return nil
+}