state/Wait: Fix race when reading exit status
Fixes:
- https://github.com/moby/moby/issues/39352

Before this change there was a race condition between State.Wait reading
the exit code from State and the State being changed immediately after the
change which ended the State.Wait.

Now, each State.Wait call holds a pointer to the StateStatus obtained
from State at the time of State.Wait call. This makes it possible to
read the correct exit code, even if the State was already modified.

The issue caused the `docker run --restart=always ...' to sometimes exit
with 0 exit code, because the process was already restarted by the time
State.Wait got the chance to read the exit code.

Test run
Before:
```
$ go test -count 1 -run TestCorrectStateWaitResultAfterRestart .
--- FAIL: TestCorrectStateWaitResultAfterRestart (0.00s)
    state_test.go:198: expected exit code 10, got 0
FAIL
FAIL    github.com/docker/docker/container      0.011s
FAIL

```

After:
```
$ go test -count 1 -run TestCorrectStateWaitResultAfterRestart .
ok      github.com/docker/docker/container      0.011s
```

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

**- What I did**
Fixed State.Wait returning unexpected StateStatus

**- How I did it**
Store StateStatus for Wait and make each Wait's goroutine store a pointer to it. The subsequent State modifications will allocate a new StateStatus, so the old one won't be affected. 

**- How to verify it**
Run tests:
```
cd container
go test -count 1 -run TestCorrectStateWaitResultAfterRestart .
```
or

(it's faster if you run multiple of those with different names)
```
while [ true ]; do
  docker run --name test --restart=always busybox sh -c 'exit 11'
  if [ ! $? -eq 11 ]; then
    echo "Reproduced!"
    break
   fi
   docker rm -f test
done
```
**- Description for the changelog**
Fix `docker run` with restart policy to sometimes exit with 0 code

**- A picture of a cute animal (not mandatory but encouraged)**
![gimmebananahuman](https://user-images.githubusercontent.com/5046555/176409011-6cdc8460-6c4b-4008-802e-a35c406f8991.jpg)


container/container.go
package container // import "github.com/docker/docker/container"

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"syscall"
	"time"

	"github.com/containerd/containerd/cio"
	containertypes "github.com/docker/docker/api/types/container"
	mounttypes "github.com/docker/docker/api/types/mount"
	swarmtypes "github.com/docker/docker/api/types/swarm"
	"github.com/docker/docker/container/stream"
	"github.com/docker/docker/daemon/exec"
	"github.com/docker/docker/daemon/logger"
	"github.com/docker/docker/daemon/logger/jsonfilelog"
	"github.com/docker/docker/daemon/logger/local"
	"github.com/docker/docker/daemon/logger/loggerutils/cache"
	"github.com/docker/docker/daemon/network"
	"github.com/docker/docker/errdefs"
	"github.com/docker/docker/image"
	"github.com/docker/docker/layer"
	"github.com/docker/docker/pkg/containerfs"
	"github.com/docker/docker/pkg/idtools"
	"github.com/docker/docker/pkg/ioutils"
	"github.com/docker/docker/pkg/system"
	"github.com/docker/docker/restartmanager"
	"github.com/docker/docker/volume"
	volumemounts "github.com/docker/docker/volume/mounts"
	units "github.com/docker/go-units"
	agentexec "github.com/moby/swarmkit/v2/agent/exec"
	"github.com/moby/sys/signal"
	"github.com/moby/sys/symlink"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

const (
	configFileName     = "config.v2.json"
	hostConfigFileName = "hostconfig.json"
)

// ExitStatus provides exit reasons for a container.
type ExitStatus struct {
	// The exit code with which the container exited.
	ExitCode int

	// Whether the container encountered an OOM.
	OOMKilled bool

	// Time at which the container died
	ExitedAt time.Time
}

// Container holds the structure defining a container object.
type Container struct {
	StreamConfig *stream.Config
	// embed for Container to support states directly.
	*State          `json:"State"`          // Needed for Engine API version <= 1.11
	Root            string                  `json:"-"` // Path to the "home" of the container, including metadata.
	BaseFS          containerfs.ContainerFS `json:"-"` // interface containing graphdriver mount
	RWLayer         layer.RWLayer           `json:"-"`
	ID              string
	Created         time.Time
	Managed         bool
	Path            string
	Args            []string
	Config          *containertypes.Config
	ImageID         image.ID `json:"Image"`
	NetworkSettings *network.Settings
	LogPath         string
	Name            string
	Driver          string
	OS              string
	// MountLabel contains the options for the 'mount' command
	MountLabel             string
	ProcessLabel           string
	RestartCount           int
	HasBeenStartedBefore   bool
	HasBeenManuallyStopped bool // used for unless-stopped restart policy
	MountPoints            map[string]*volumemounts.MountPoint
	HostConfig             *containertypes.HostConfig `json:"-"` // do not serialize the host config in the json, otherwise we'll make the container unportable
	ExecCommands           *exec.Store                `json:"-"`
	DependencyStore        agentexec.DependencyGetter `json:"-"`
	SecretReferences       []*swarmtypes.SecretReference
	ConfigReferences       []*swarmtypes.ConfigReference
	// logDriver for closing
	LogDriver      logger.Logger  `json:"-"`
	LogCopier      *logger.Copier `json:"-"`
	restartManager restartmanager.RestartManager
	attachContext  *attachContext

	// Fields here are specific to Unix platforms
	AppArmorProfile string
	HostnamePath    string
	HostsPath       string
	ShmPath         string
	ResolvConfPath  string
	SeccompProfile  string
	NoNewPrivileges bool

	// Fields here are specific to Windows
	NetworkSharedContainerID string            `json:"-"`
	SharedEndpointList       []string          `json:"-"`
	LocalLogCacheMeta        localLogCacheMeta `json:",omitempty"`
}

type localLogCacheMeta struct {
	HaveNotifyEnabled bool
}

// NewBaseContainer creates a new container with its
// basic configuration.
func NewBaseContainer(id, root string) *Container {
	return &Container{
		ID:            id,
		State:         NewState(),
		ExecCommands:  exec.NewStore(),
		Root:          root,
		MountPoints:   make(map[string]*volumemounts.MountPoint),
		StreamConfig:  stream.NewConfig(),
		attachContext: &attachContext{},
	}
}

// FromDisk loads the container configuration stored in the host.
func (container *Container) FromDisk() error {
	pth, err := container.ConfigPath()
	if err != nil {
		return err
	}

	jsonSource, err := os.Open(pth)
	if err != nil {
		return err
	}
	defer jsonSource.Close()

	dec := json.NewDecoder(jsonSource)

	// Load container settings
	if err := dec.Decode(container); err != nil {
		return err
	}

	// Ensure the operating system is set if blank. Assume it is the OS of the
	// host OS if not, to ensure containers created before multiple-OS
	// support are migrated
	if container.OS == "" {
		container.OS = runtime.GOOS
	}

	return container.readHostConfig()
}

// toDisk writes the container's configuration (config.v2.json, hostconfig.json)
// to disk and returns a deep copy.
func (container *Container) toDisk() (*Container, error) {
	pth, err := container.ConfigPath()
	if err != nil {
		return nil, err
	}

	// Save container settings
	f, err := ioutils.NewAtomicFileWriter(pth, 0600)
	if err != nil {
		return nil, err
	}
	defer f.Close()

	var buf bytes.Buffer
	w := io.MultiWriter(&buf, f)
	if err := json.NewEncoder(w).Encode(container); err != nil {
		return nil, err
	}

	var deepCopy Container
	if err := json.NewDecoder(&buf).Decode(&deepCopy); err != nil {
		return nil, err
	}
	deepCopy.HostConfig, err = container.WriteHostConfig()
	if err != nil {
		return nil, err
	}
	return &deepCopy, nil
}

// CheckpointTo makes the Container's current state visible to queries, and persists state.
// Callers must hold a Container lock.
func (container *Container) CheckpointTo(store ViewDB) error {
	deepCopy, err := container.toDisk()
	if err != nil {
		return err
	}
	return store.Save(deepCopy)
}

// readHostConfig reads the host configuration from disk for the container.
func (container *Container) readHostConfig() error {
	container.HostConfig = &containertypes.HostConfig{}
	// If the hostconfig file does not exist, do not read it.
	// (We still have to initialize container.HostConfig,
	// but that's OK, since we just did that above.)
	pth, err := container.HostConfigPath()
	if err != nil {
		return err
	}

	f, err := os.Open(pth)
	if err != nil {
		if os.IsNotExist(err) {
			return nil
		}
		return err
	}
	defer f.Close()

	if err := json.NewDecoder(f).Decode(&container.HostConfig); err != nil {
		return err
	}

	container.InitDNSHostConfig()

	return nil
}

// WriteHostConfig saves the host configuration on disk for the container,
// and returns a deep copy of the saved object. Callers must hold a Container lock.
func (container *Container) WriteHostConfig() (*containertypes.HostConfig, error) {
	var (
		buf      bytes.Buffer
		deepCopy containertypes.HostConfig
	)

	pth, err := container.HostConfigPath()
	if err != nil {
		return nil, err
	}

	f, err := ioutils.NewAtomicFileWriter(pth, 0600)
	if err != nil {
		return nil, err
	}
	defer f.Close()

	w := io.MultiWriter(&buf, f)
	if err := json.NewEncoder(w).Encode(&container.HostConfig); err != nil {
		return nil, err
	}

	if err := json.NewDecoder(&buf).Decode(&deepCopy); err != nil {
		return nil, err
	}
	return &deepCopy, nil
}

// SetupWorkingDirectory sets up the container's working directory as set in container.Config.WorkingDir
func (container *Container) SetupWorkingDirectory(rootIdentity idtools.Identity) error {
	if container.Config.WorkingDir == "" {
		return nil
	}

	container.Config.WorkingDir = filepath.Clean(container.Config.WorkingDir)
	pth, err := container.GetResourcePath(container.Config.WorkingDir)
	if err != nil {
		return err
	}

	if err := idtools.MkdirAllAndChownNew(pth, 0755, rootIdentity); err != nil {
		pthInfo, err2 := os.Stat(pth)
		if err2 == nil && pthInfo != nil && !pthInfo.IsDir() {
			return errors.Errorf("Cannot mkdir: %s is not a directory", container.Config.WorkingDir)
		}

		return err
	}

	return nil
}

// GetResourcePath evaluates `path` in the scope of the container's BaseFS, with proper path
// sanitisation. Symlinks are all scoped to the BaseFS of the container, as
// though the container's BaseFS was `/`.
//
// The BaseFS of a container is the host-facing path which is bind-mounted as
// `/` inside the container. This method is essentially used to access a
// particular path inside the container as though you were a process in that
// container.
//
// # NOTE
// The returned path is *only* safely scoped inside the container's BaseFS
// if no component of the returned path changes (such as a component
// symlinking to a different path) between using this method and using the
// path. See symlink.FollowSymlinkInScope for more details.
func (container *Container) GetResourcePath(path string) (string, error) {
	if container.BaseFS == nil {
		return "", errors.New("GetResourcePath: BaseFS of container " + container.ID + " is unexpectedly nil")
	}
	// IMPORTANT - These are paths on the OS where the daemon is running, hence
	// any filepath operations must be done in an OS agnostic way.
	r, e := container.BaseFS.ResolveScopedPath(path, false)

	// Log this here on the daemon side as there's otherwise no indication apart
	// from the error being propagated all the way back to the client. This makes
	// debugging significantly easier and clearly indicates the error comes from the daemon.
	if e != nil {
		logrus.Errorf("Failed to ResolveScopedPath BaseFS %s path %s %s\n", container.BaseFS.Path(), path, e)
	}
	return r, e
}

// GetRootResourcePath evaluates `path` in the scope of the container's root, with proper path
// sanitisation. Symlinks are all scoped to the root of the container, as
// though the container's root was `/`.
//
// The root of a container is the host-facing configuration metadata directory.
// Only use this method to safely access the container's `container.json` or
// other metadata files. If in doubt, use container.GetResourcePath.
//
// # NOTE
// The returned path is *only* safely scoped inside the container's root
// if no component of the returned path changes (such as a component
// symlinking to a different path) between using this method and using the
// path. See symlink.FollowSymlinkInScope for more details.
func (container *Container) GetRootResourcePath(path string) (string, error) {
	// IMPORTANT - These are paths on the OS where the daemon is running, hence
	// any filepath operations must be done in an OS agnostic way.
	cleanPath := filepath.Join(string(os.PathSeparator), path)
	return symlink.FollowSymlinkInScope(filepath.Join(container.Root, cleanPath), container.Root)
}

// ExitOnNext signals to the monitor that it should not restart the container
// after we send the kill signal.
func (container *Container) ExitOnNext() {
	container.RestartManager().Cancel()
}

// HostConfigPath returns the path to the container's JSON hostconfig
func (container *Container) HostConfigPath() (string, error) {
	return container.GetRootResourcePath(hostConfigFileName)
}

// ConfigPath returns the path to the container's JSON config
func (container *Container) ConfigPath() (string, error) {
	return container.GetRootResourcePath(configFileName)
}

// CheckpointDir returns the directory checkpoints are stored in
func (container *Container) CheckpointDir() string {
	return filepath.Join(container.Root, "checkpoints")
}

// StartLogger starts a new logger driver for the container.
func (container *Container) StartLogger() (logger.Logger, error) {
	cfg := container.HostConfig.LogConfig
	initDriver, err := logger.GetLogDriver(cfg.Type)
	if err != nil {
		return nil, errors.Wrap(err, "failed to get logging factory")
	}
	info := logger.Info{
		Config:              cfg.Config,
		ContainerID:         container.ID,
		ContainerName:       container.Name,
		ContainerEntrypoint: container.Path,
		ContainerArgs:       container.Args,
		ContainerImageID:    container.ImageID.String(),
		ContainerImageName:  container.Config.Image,
		ContainerCreated:    container.Created,
		ContainerEnv:        container.Config.Env,
		ContainerLabels:     container.Config.Labels,
		DaemonName:          "docker",
	}

	// Set logging file for "json-logger"
	// TODO(@cpuguy83): Setup here based on log driver is a little weird.
	switch cfg.Type {
	case jsonfilelog.Name:
		info.LogPath, err = container.GetRootResourcePath(fmt.Sprintf("%s-json.log", container.ID))
		if err != nil {
			return nil, err
		}

		container.LogPath = info.LogPath
	case local.Name:
		// Do not set container.LogPath for the local driver
		// This would expose the value to the API, which should not be done as it means
		// that the log file implementation would become a stable API that cannot change.
		logDir, err := container.GetRootResourcePath("local-logs")
		if err != nil {
			return nil, err
		}
		if err := os.MkdirAll(logDir, 0700); err != nil {
			return nil, errdefs.System(errors.Wrap(err, "error creating local logs dir"))
		}
		info.LogPath = filepath.Join(logDir, "container.log")
	}

	l, err := initDriver(info)
	if err != nil {
		return nil, err
	}

	if containertypes.LogMode(cfg.Config["mode"]) == containertypes.LogModeNonBlock {
		bufferSize := int64(-1)
		if s, exists := cfg.Config["max-buffer-size"]; exists {
			bufferSize, err = units.RAMInBytes(s)
			if err != nil {
				return nil, err
			}
		}
		l = logger.NewRingLogger(l, info, bufferSize)
	}

	if _, ok := l.(logger.LogReader); !ok {
		if cache.ShouldUseCache(cfg.Config) {
			logPath, err := container.GetRootResourcePath("container-cached.log")
			if err != nil {
				return nil, err
			}

			if !container.LocalLogCacheMeta.HaveNotifyEnabled {
				logrus.WithField("container", container.ID).WithField("driver", container.HostConfig.LogConfig.Type).Info("Configured log driver does not support reads, enabling local file cache for container logs")
				container.LocalLogCacheMeta.HaveNotifyEnabled = true
			}
			info.LogPath = logPath
			l, err = cache.WithLocalCache(l, info)
			if err != nil {
				return nil, errors.Wrap(err, "error setting up local container log cache")
			}
		}
	}
	return l, nil
}

// GetProcessLabel returns the process label for the container.
func (container *Container) GetProcessLabel() string {
	// even if we have a process label return "" if we are running
	// in privileged mode
	if container.HostConfig.Privileged {
		return ""
	}
	return container.ProcessLabel
}

// GetMountLabel returns the mounting label for the container.
// This label is empty if the container is privileged.
func (container *Container) GetMountLabel() string {
	return container.MountLabel
}

// GetExecIDs returns the list of exec commands running on the container.
func (container *Container) GetExecIDs() []string {
	return container.ExecCommands.List()
}

// ShouldRestart decides whether the daemon should restart the container or not.
// This is based on the container's restart policy.
func (container *Container) ShouldRestart() bool {
	shouldRestart, _, _ := container.RestartManager().ShouldRestart(uint32(container.ExitCode()), container.HasBeenManuallyStopped, container.FinishedAt.Sub(container.StartedAt))
	return shouldRestart
}

// AddMountPointWithVolume adds a new mount point configured with a volume to the container.
func (container *Container) AddMountPointWithVolume(destination string, vol volume.Volume, rw bool) {
	volumeParser := volumemounts.NewParser()
	container.MountPoints[destination] = &volumemounts.MountPoint{
		Type:        mounttypes.TypeVolume,
		Name:        vol.Name(),
		Driver:      vol.DriverName(),
		Destination: destination,
		RW:          rw,
		Volume:      vol,
		CopyData:    volumeParser.DefaultCopyMode(),
	}
}

// UnmountVolumes unmounts all volumes
func (container *Container) UnmountVolumes(volumeEventLog func(name, action string, attributes map[string]string)) error {
	var errors []string
	for _, volumeMount := range container.MountPoints {
		if volumeMount.Volume == nil {
			continue
		}

		if err := volumeMount.Cleanup(); err != nil {
			errors = append(errors, err.Error())
			continue
		}

		attributes := map[string]string{
			"driver":    volumeMount.Volume.DriverName(),
			"container": container.ID,
		}
		volumeEventLog(volumeMount.Volume.Name(), "unmount", attributes)
	}
	if len(errors) > 0 {
		return fmt.Errorf("error while unmounting volumes for container %s: %s", container.ID, strings.Join(errors, "; "))
	}
	return nil
}

// IsDestinationMounted checks whether a path is mounted on the container or not.
func (container *Container) IsDestinationMounted(destination string) bool {
	return container.MountPoints[destination] != nil
}

// StopSignal returns the signal used to stop the container.
func (container *Container) StopSignal() syscall.Signal {
	var stopSignal syscall.Signal
	if container.Config.StopSignal != "" {
		stopSignal, _ = signal.ParseSignal(container.Config.StopSignal)
	}

	if stopSignal == 0 {
		stopSignal, _ = signal.ParseSignal(defaultStopSignal)
	}
	return stopSignal
}

// StopTimeout returns the timeout (in seconds) used to stop the container.
func (container *Container) StopTimeout() int {
	if container.Config.StopTimeout != nil {
		return *container.Config.StopTimeout
	}
	return defaultStopTimeout
}

// InitDNSHostConfig ensures that the dns fields are never nil.
// New containers don't ever have those fields nil,
// but pre created containers can still have those nil values.
// The non-recommended host configuration in the start api can
// make these fields nil again, this corrects that issue until
// we remove that behavior for good.
// See https://github.com/docker/docker/pull/17779
// for a more detailed explanation on why we don't want that.
func (container *Container) InitDNSHostConfig() {
	container.Lock()
	defer container.Unlock()
	if container.HostConfig.DNS == nil {
		container.HostConfig.DNS = make([]string, 0)
	}

	if container.HostConfig.DNSSearch == nil {
		container.HostConfig.DNSSearch = make([]string, 0)
	}

	if container.HostConfig.DNSOptions == nil {
		container.HostConfig.DNSOptions = make([]string, 0)
	}
}

// UpdateMonitor updates monitor configure for running container
func (container *Container) UpdateMonitor(restartPolicy containertypes.RestartPolicy) {
	type policySetter interface {
		SetPolicy(containertypes.RestartPolicy)
	}

	if rm, ok := container.RestartManager().(policySetter); ok {
		rm.SetPolicy(restartPolicy)
	}
}

// FullHostname returns hostname and optional domain appended to it.
func (container *Container) FullHostname() string {
	fullHostname := container.Config.Hostname
	if container.Config.Domainname != "" {
		fullHostname = fmt.Sprintf("%s.%s", fullHostname, container.Config.Domainname)
	}
	return fullHostname
}

// RestartManager returns the current restartmanager instance connected to container.
func (container *Container) RestartManager() restartmanager.RestartManager {
	if container.restartManager == nil {
		container.restartManager = restartmanager.New(container.HostConfig.RestartPolicy, container.RestartCount)
	}
	return container.restartManager
}

// ResetRestartManager initializes new restartmanager based on container config
func (container *Container) ResetRestartManager(resetCount bool) {
	if container.restartManager != nil {
		container.restartManager.Cancel()
	}
	if resetCount {
		container.RestartCount = 0
	}
	container.restartManager = nil
}

type attachContext struct {
	ctx    context.Context
	cancel context.CancelFunc
	mu     sync.Mutex
}

// InitAttachContext initializes or returns existing context for attach calls to
// track container liveness.
func (container *Container) InitAttachContext() context.Context {
	container.attachContext.mu.Lock()
	defer container.attachContext.mu.Unlock()
	if container.attachContext.ctx == nil {
		container.attachContext.ctx, container.attachContext.cancel = context.WithCancel(context.Background())
	}
	return container.attachContext.ctx
}

// CancelAttachContext cancels attach context. All attach calls should detach
// after this call.
func (container *Container) CancelAttachContext() {
	container.attachContext.mu.Lock()
	if container.attachContext.ctx != nil {
		container.attachContext.cancel()
		container.attachContext.ctx = nil
	}
	container.attachContext.mu.Unlock()
}

func (container *Container) startLogging() error {
	if container.HostConfig.LogConfig.Type == "none" {
		return nil // do not start logging routines
	}

	l, err := container.StartLogger()
	if err != nil {
		return fmt.Errorf("failed to initialize logging driver: %v", err)
	}

	copier := logger.NewCopier(map[string]io.Reader{"stdout": container.StdoutPipe(), "stderr": container.StderrPipe()}, l)
	container.LogCopier = copier
	copier.Run()
	container.LogDriver = l

	return nil
}

// StdinPipe gets the stdin stream of the container
func (container *Container) StdinPipe() io.WriteCloser {
	return container.StreamConfig.StdinPipe()
}

// StdoutPipe gets the stdout stream of the container
func (container *Container) StdoutPipe() io.ReadCloser {
	return container.StreamConfig.StdoutPipe()
}

// StderrPipe gets the stderr stream of the container
func (container *Container) StderrPipe() io.ReadCloser {
	return container.StreamConfig.StderrPipe()
}

// CloseStreams closes the container's stdio streams
func (container *Container) CloseStreams() error {
	return container.StreamConfig.CloseStreams()
}

// InitializeStdio is called by libcontainerd to connect the stdio.
func (container *Container) InitializeStdio(iop *cio.DirectIO) (cio.IO, error) {
	if err := container.startLogging(); err != nil {
		container.Reset(false)
		return nil, err
	}

	container.StreamConfig.CopyToPipe(iop)

	if container.StreamConfig.Stdin() == nil && !container.Config.Tty {
		if iop.Stdin != nil {
			if err := iop.Stdin.Close(); err != nil {
				logrus.Warnf("error closing stdin: %+v", err)
			}
		}
	}

	return &rio{IO: iop, sc: container.StreamConfig}, nil
}

// MountsResourcePath returns the path where mounts are stored for the given mount
func (container *Container) MountsResourcePath(mount string) (string, error) {
	return container.GetRootResourcePath(filepath.Join("mounts", mount))
}

// SecretMountPath returns the path of the secret mount for the container
func (container *Container) SecretMountPath() (string, error) {
	return container.MountsResourcePath("secrets")
}

// SecretFilePath returns the path to the location of a secret on the host.
func (container *Container) SecretFilePath(secretRef swarmtypes.SecretReference) (string, error) {
	secrets, err := container.SecretMountPath()
	if err != nil {
		return "", err
	}
	return filepath.Join(secrets, secretRef.SecretID), nil
}

func getSecretTargetPath(r *swarmtypes.SecretReference) string {
	if filepath.IsAbs(r.File.Name) {
		return r.File.Name
	}

	return filepath.Join(containerSecretMountPath, r.File.Name)
}

// getConfigTargetPath makes sure that config paths inside the container are
// absolute, as required by the runtime spec, and enforced by runc >= 1.0.0-rc94.
// see https://github.com/opencontainers/runc/issues/2928
func getConfigTargetPath(r *swarmtypes.ConfigReference) string {
	if filepath.IsAbs(r.File.Name) {
		return r.File.Name
	}

	return filepath.Join(containerConfigMountPath, r.File.Name)
}

// CreateDaemonEnvironment creates a new environment variable slice for this container.
func (container *Container) CreateDaemonEnvironment(tty bool, linkedEnv []string) []string {
	// Setup environment
	ctrOS := container.OS
	if ctrOS == "" {
		ctrOS = runtime.GOOS
	}

	// Figure out what size slice we need so we can allocate this all at once.
	envSize := len(container.Config.Env)
	if runtime.GOOS != "windows" {
		envSize += 2 + len(linkedEnv)
	}
	if tty {
		envSize++
	}

	env := make([]string, 0, envSize)
	if runtime.GOOS != "windows" {
		env = append(env, "PATH="+system.DefaultPathEnv(ctrOS))
		env = append(env, "HOSTNAME="+container.Config.Hostname)
		if tty {
			env = append(env, "TERM=xterm")
		}
		env = append(env, linkedEnv...)
	}

	// because the env on the container can override certain default values
	// we need to replace the 'env' keys where they match and append anything
	// else.
	env = ReplaceOrAppendEnvValues(env, container.Config.Env)
	return env
}

type rio struct {
	cio.IO

	sc *stream.Config
}

func (i *rio) Close() error {
	i.IO.Close()

	return i.sc.CloseStreams()
}

func (i *rio) Wait() {
	i.sc.Wait(context.Background())

	i.IO.Wait()
}

package container // import "github.com/docker/docker/container"

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"syscall"
	"time"

	"github.com/containerd/containerd/cio"
	containertypes "github.com/docker/docker/api/types/container"
	mounttypes "github.com/docker/docker/api/types/mount"
	swarmtypes "github.com/docker/docker/api/types/swarm"
	"github.com/docker/docker/container/stream"
	"github.com/docker/docker/daemon/exec"
	"github.com/docker/docker/daemon/logger"
	"github.com/docker/docker/daemon/logger/jsonfilelog"
	"github.com/docker/docker/daemon/logger/local"
	"github.com/docker/docker/daemon/logger/loggerutils/cache"
	"github.com/docker/docker/daemon/network"
	"github.com/docker/docker/errdefs"
	"github.com/docker/docker/image"
	"github.com/docker/docker/layer"
	"github.com/docker/docker/pkg/containerfs"
	"github.com/docker/docker/pkg/idtools"
	"github.com/docker/docker/pkg/ioutils"
	"github.com/docker/docker/pkg/system"
	"github.com/docker/docker/restartmanager"
	"github.com/docker/docker/volume"
	volumemounts "github.com/docker/docker/volume/mounts"
	units "github.com/docker/go-units"
	agentexec "github.com/moby/swarmkit/v2/agent/exec"
	"github.com/moby/sys/signal"
	"github.com/moby/sys/symlink"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

const (
	configFileName     = "config.v2.json"
	hostConfigFileName = "hostconfig.json"
)

// ExitStatus provides exit reasons for a container.
type ExitStatus struct {
	// The exit code with which the container exited.
	ExitCode int

	// Whether the container encountered an OOM.
	OOMKilled bool

	// Time at which the container died
	ExitedAt time.Time
}

// Container holds the structure defining a container object.
type Container struct {
	StreamConfig *stream.Config
	// embed for Container to support states directly.
	*State          `json:"State"`          // Needed for Engine API version <= 1.11
	Root            string                  `json:"-"` // Path to the "home" of the container, including metadata.
	BaseFS          containerfs.ContainerFS `json:"-"` // interface containing graphdriver mount
	RWLayer         layer.RWLayer           `json:"-"`
	ID              string
	Created         time.Time
	Managed         bool
	Path            string
	Args            []string
	Config          *containertypes.Config
	ImageID         image.ID `json:"Image"`
	NetworkSettings *network.Settings
	LogPath         string
	Name            string
	Driver          string
	OS              string
	// MountLabel contains the options for the 'mount' command
	MountLabel               string
	ProcessLabel             string
	RestartCount             int
	HasBeenStartedBefore     bool
	HasBeenManuallyStopped   bool // used for unless-stopped restart policy
	HasBeenManuallyRestarted bool `json:"-"` // used to distinguish restart caused by restart policy from the manual one
	MountPoints              map[string]*volumemounts.MountPoint
	HostConfig               *containertypes.HostConfig `json:"-"` // do not serialize the host config in the json, otherwise we'll make the container unportable
	ExecCommands             *exec.Store                `json:"-"`
	DependencyStore          agentexec.DependencyGetter `json:"-"`
	SecretReferences         []*swarmtypes.SecretReference
	ConfigReferences         []*swarmtypes.ConfigReference
	// logDriver for closing
	LogDriver      logger.Logger  `json:"-"`
	LogCopier      *logger.Copier `json:"-"`
	restartManager restartmanager.RestartManager
	attachContext  *attachContext

	// Fields here are specific to Unix platforms
	AppArmorProfile string
	HostnamePath    string
	HostsPath       string
	ShmPath         string
	ResolvConfPath  string
	SeccompProfile  string
	NoNewPrivileges bool

	// Fields here are specific to Windows
	NetworkSharedContainerID string            `json:"-"`
	SharedEndpointList       []string          `json:"-"`
	LocalLogCacheMeta        localLogCacheMeta `json:",omitempty"`
}

type localLogCacheMeta struct {
	HaveNotifyEnabled bool
}

// NewBaseContainer creates a new container with its
// basic configuration.
func NewBaseContainer(id, root string) *Container {
	return &Container{
		ID:            id,
		State:         NewState(),
		ExecCommands:  exec.NewStore(),
		Root:          root,
		MountPoints:   make(map[string]*volumemounts.MountPoint),
		StreamConfig:  stream.NewConfig(),
		attachContext: &attachContext{},
	}
}

// FromDisk loads the container configuration stored in the host.
func (container *Container) FromDisk() error {
	pth, err := container.ConfigPath()
	if err != nil {
		return err
	}

	jsonSource, err := os.Open(pth)
	if err != nil {
		return err
	}
	defer jsonSource.Close()

	dec := json.NewDecoder(jsonSource)

	// Load container settings
	if err := dec.Decode(container); err != nil {
		return err
	}

	// Ensure the operating system is set if blank. Assume it is the OS of the
	// host OS if not, to ensure containers created before multiple-OS
	// support are migrated
	if container.OS == "" {
		container.OS = runtime.GOOS
	}

	return container.readHostConfig()
}

// toDisk writes the container's configuration (config.v2.json, hostconfig.json)
// to disk and returns a deep copy.
func (container *Container) toDisk() (*Container, error) {
	pth, err := container.ConfigPath()
	if err != nil {
		return nil, err
	}

	// Save container settings
	f, err := ioutils.NewAtomicFileWriter(pth, 0600)
	if err != nil {
		return nil, err
	}
	defer f.Close()

	var buf bytes.Buffer
	w := io.MultiWriter(&buf, f)
	if err := json.NewEncoder(w).Encode(container); err != nil {
		return nil, err
	}

	var deepCopy Container
	if err := json.NewDecoder(&buf).Decode(&deepCopy); err != nil {
		return nil, err
	}
	deepCopy.HostConfig, err = container.WriteHostConfig()
	if err != nil {
		return nil, err
	}
	return &deepCopy, nil
}

// CheckpointTo makes the Container's current state visible to queries, and persists state.
// Callers must hold a Container lock.
func (container *Container) CheckpointTo(store ViewDB) error {
	deepCopy, err := container.toDisk()
	if err != nil {
		return err
	}
	return store.Save(deepCopy)
}

// readHostConfig reads the host configuration from disk for the container.
func (container *Container) readHostConfig() error {
	container.HostConfig = &containertypes.HostConfig{}
	// If the hostconfig file does not exist, do not read it.
	// (We still have to initialize container.HostConfig,
	// but that's OK, since we just did that above.)
	pth, err := container.HostConfigPath()
	if err != nil {
		return err
	}

	f, err := os.Open(pth)
	if err != nil {
		if os.IsNotExist(err) {
			return nil
		}
		return err
	}
	defer f.Close()

	if err := json.NewDecoder(f).Decode(&container.HostConfig); err != nil {
		return err
	}

	container.InitDNSHostConfig()

	return nil
}

// WriteHostConfig saves the host configuration on disk for the container,
// and returns a deep copy of the saved object. Callers must hold a Container lock.
func (container *Container) WriteHostConfig() (*containertypes.HostConfig, error) {
	var (
		buf      bytes.Buffer
		deepCopy containertypes.HostConfig
	)

	pth, err := container.HostConfigPath()
	if err != nil {
		return nil, err
	}

	f, err := ioutils.NewAtomicFileWriter(pth, 0600)
	if err != nil {
		return nil, err
	}
	defer f.Close()

	w := io.MultiWriter(&buf, f)
	if err := json.NewEncoder(w).Encode(&container.HostConfig); err != nil {
		return nil, err
	}

	if err := json.NewDecoder(&buf).Decode(&deepCopy); err != nil {
		return nil, err
	}
	return &deepCopy, nil
}

// SetupWorkingDirectory sets up the container's working directory as set in container.Config.WorkingDir
func (container *Container) SetupWorkingDirectory(rootIdentity idtools.Identity) error {
	if container.Config.WorkingDir == "" {
		return nil
	}

	container.Config.WorkingDir = filepath.Clean(container.Config.WorkingDir)
	pth, err := container.GetResourcePath(container.Config.WorkingDir)
	if err != nil {
		return err
	}

	if err := idtools.MkdirAllAndChownNew(pth, 0755, rootIdentity); err != nil {
		pthInfo, err2 := os.Stat(pth)
		if err2 == nil && pthInfo != nil && !pthInfo.IsDir() {
			return errors.Errorf("Cannot mkdir: %s is not a directory", container.Config.WorkingDir)
		}

		return err
	}

	return nil
}

// GetResourcePath evaluates `path` in the scope of the container's BaseFS, with proper path
// sanitisation. Symlinks are all scoped to the BaseFS of the container, as
// though the container's BaseFS was `/`.
//
// The BaseFS of a container is the host-facing path which is bind-mounted as
// `/` inside the container. This method is essentially used to access a
// particular path inside the container as though you were a process in that
// container.
//
// # NOTE
// The returned path is *only* safely scoped inside the container's BaseFS
// if no component of the returned path changes (such as a component
// symlinking to a different path) between using this method and using the
// path. See symlink.FollowSymlinkInScope for more details.
func (container *Container) GetResourcePath(path string) (string, error) {
	if container.BaseFS == nil {
		return "", errors.New("GetResourcePath: BaseFS of container " + container.ID + " is unexpectedly nil")
	}
	// IMPORTANT - These are paths on the OS where the daemon is running, hence
	// any filepath operations must be done in an OS agnostic way.
	r, e := container.BaseFS.ResolveScopedPath(path, false)

	// Log this here on the daemon side as there's otherwise no indication apart
	// from the error being propagated all the way back to the client. This makes
	// debugging significantly easier and clearly indicates the error comes from the daemon.
	if e != nil {
		logrus.Errorf("Failed to ResolveScopedPath BaseFS %s path %s %s\n", container.BaseFS.Path(), path, e)
	}
	return r, e
}

// GetRootResourcePath evaluates `path` in the scope of the container's root, with proper path
// sanitisation. Symlinks are all scoped to the root of the container, as
// though the container's root was `/`.
//
// The root of a container is the host-facing configuration metadata directory.
// Only use this method to safely access the container's `container.json` or
// other metadata files. If in doubt, use container.GetResourcePath.
//
// # NOTE
// The returned path is *only* safely scoped inside the container's root
// if no component of the returned path changes (such as a component
// symlinking to a different path) between using this method and using the
// path. See symlink.FollowSymlinkInScope for more details.
func (container *Container) GetRootResourcePath(path string) (string, error) {
	// IMPORTANT - These are paths on the OS where the daemon is running, hence
	// any filepath operations must be done in an OS agnostic way.
	cleanPath := filepath.Join(string(os.PathSeparator), path)
	return symlink.FollowSymlinkInScope(filepath.Join(container.Root, cleanPath), container.Root)
}

// ExitOnNext signals to the monitor that it should not restart the container
// after we send the kill signal.
func (container *Container) ExitOnNext() {
	container.RestartManager().Cancel()
}

// HostConfigPath returns the path to the container's JSON hostconfig
func (container *Container) HostConfigPath() (string, error) {
	return container.GetRootResourcePath(hostConfigFileName)
}

// ConfigPath returns the path to the container's JSON config
func (container *Container) ConfigPath() (string, error) {
	return container.GetRootResourcePath(configFileName)
}

// CheckpointDir returns the directory checkpoints are stored in
func (container *Container) CheckpointDir() string {
	return filepath.Join(container.Root, "checkpoints")
}

// StartLogger starts a new logger driver for the container.
func (container *Container) StartLogger() (logger.Logger, error) {
	cfg := container.HostConfig.LogConfig
	initDriver, err := logger.GetLogDriver(cfg.Type)
	if err != nil {
		return nil, errors.Wrap(err, "failed to get logging factory")
	}
	info := logger.Info{
		Config:              cfg.Config,
		ContainerID:         container.ID,
		ContainerName:       container.Name,
		ContainerEntrypoint: container.Path,
		ContainerArgs:       container.Args,
		ContainerImageID:    container.ImageID.String(),
		ContainerImageName:  container.Config.Image,
		ContainerCreated:    container.Created,
		ContainerEnv:        container.Config.Env,
		ContainerLabels:     container.Config.Labels,
		DaemonName:          "docker",
	}

	// Set logging file for "json-logger"
	// TODO(@cpuguy83): Setup here based on log driver is a little weird.
	switch cfg.Type {
	case jsonfilelog.Name:
		info.LogPath, err = container.GetRootResourcePath(fmt.Sprintf("%s-json.log", container.ID))
		if err != nil {
			return nil, err
		}

		container.LogPath = info.LogPath
	case local.Name:
		// Do not set container.LogPath for the local driver
		// This would expose the value to the API, which should not be done as it means
		// that the log file implementation would become a stable API that cannot change.
		logDir, err := container.GetRootResourcePath("local-logs")
		if err != nil {
			return nil, err
		}
		if err := os.MkdirAll(logDir, 0700); err != nil {
			return nil, errdefs.System(errors.Wrap(err, "error creating local logs dir"))
		}
		info.LogPath = filepath.Join(logDir, "container.log")
	}

	l, err := initDriver(info)
	if err != nil {
		return nil, err
	}

	if containertypes.LogMode(cfg.Config["mode"]) == containertypes.LogModeNonBlock {
		bufferSize := int64(-1)
		if s, exists := cfg.Config["max-buffer-size"]; exists {
			bufferSize, err = units.RAMInBytes(s)
			if err != nil {
				return nil, err
			}
		}
		l = logger.NewRingLogger(l, info, bufferSize)
	}

	if _, ok := l.(logger.LogReader); !ok {
		if cache.ShouldUseCache(cfg.Config) {
			logPath, err := container.GetRootResourcePath("container-cached.log")
			if err != nil {
				return nil, err
			}

			if !container.LocalLogCacheMeta.HaveNotifyEnabled {
				logrus.WithField("container", container.ID).WithField("driver", container.HostConfig.LogConfig.Type).Info("Configured log driver does not support reads, enabling local file cache for container logs")
				container.LocalLogCacheMeta.HaveNotifyEnabled = true
			}
			info.LogPath = logPath
			l, err = cache.WithLocalCache(l, info)
			if err != nil {
				return nil, errors.Wrap(err, "error setting up local container log cache")
			}
		}
	}
	return l, nil
}

// GetProcessLabel returns the process label for the container.
func (container *Container) GetProcessLabel() string {
	// even if we have a process label return "" if we are running
	// in privileged mode
	if container.HostConfig.Privileged {
		return ""
	}
	return container.ProcessLabel
}

// GetMountLabel returns the mounting label for the container.
// This label is empty if the container is privileged.
func (container *Container) GetMountLabel() string {
	return container.MountLabel
}

// GetExecIDs returns the list of exec commands running on the container.
func (container *Container) GetExecIDs() []string {
	return container.ExecCommands.List()
}

// ShouldRestart decides whether the daemon should restart the container or not.
// This is based on the container's restart policy.
func (container *Container) ShouldRestart() bool {
	shouldRestart, _, _ := container.RestartManager().ShouldRestart(uint32(container.ExitCode()), container.HasBeenManuallyStopped, container.FinishedAt.Sub(container.StartedAt))
	return shouldRestart
}

// AddMountPointWithVolume adds a new mount point configured with a volume to the container.
func (container *Container) AddMountPointWithVolume(destination string, vol volume.Volume, rw bool) {
	volumeParser := volumemounts.NewParser()
	container.MountPoints[destination] = &volumemounts.MountPoint{
		Type:        mounttypes.TypeVolume,
		Name:        vol.Name(),
		Driver:      vol.DriverName(),
		Destination: destination,
		RW:          rw,
		Volume:      vol,
		CopyData:    volumeParser.DefaultCopyMode(),
	}
}

// UnmountVolumes unmounts all volumes
func (container *Container) UnmountVolumes(volumeEventLog func(name, action string, attributes map[string]string)) error {
	var errors []string
	for _, volumeMount := range container.MountPoints {
		if volumeMount.Volume == nil {
			continue
		}

		if err := volumeMount.Cleanup(); err != nil {
			errors = append(errors, err.Error())
			continue
		}

		attributes := map[string]string{
			"driver":    volumeMount.Volume.DriverName(),
			"container": container.ID,
		}
		volumeEventLog(volumeMount.Volume.Name(), "unmount", attributes)
	}
	if len(errors) > 0 {
		return fmt.Errorf("error while unmounting volumes for container %s: %s", container.ID, strings.Join(errors, "; "))
	}
	return nil
}

// IsDestinationMounted checks whether a path is mounted on the container or not.
func (container *Container) IsDestinationMounted(destination string) bool {
	return container.MountPoints[destination] != nil
}

// StopSignal returns the signal used to stop the container.
func (container *Container) StopSignal() syscall.Signal {
	var stopSignal syscall.Signal
	if container.Config.StopSignal != "" {
		stopSignal, _ = signal.ParseSignal(container.Config.StopSignal)
	}

	if stopSignal == 0 {
		stopSignal, _ = signal.ParseSignal(defaultStopSignal)
	}
	return stopSignal
}

// StopTimeout returns the timeout (in seconds) used to stop the container.
func (container *Container) StopTimeout() int {
	if container.Config.StopTimeout != nil {
		return *container.Config.StopTimeout
	}
	return defaultStopTimeout
}

// InitDNSHostConfig ensures that the dns fields are never nil.
// New containers don't ever have those fields nil,
// but pre created containers can still have those nil values.
// The non-recommended host configuration in the start api can
// make these fields nil again, this corrects that issue until
// we remove that behavior for good.
// See https://github.com/docker/docker/pull/17779
// for a more detailed explanation on why we don't want that.
func (container *Container) InitDNSHostConfig() {
	container.Lock()
	defer container.Unlock()
	if container.HostConfig.DNS == nil {
		container.HostConfig.DNS = make([]string, 0)
	}

	if container.HostConfig.DNSSearch == nil {
		container.HostConfig.DNSSearch = make([]string, 0)
	}

	if container.HostConfig.DNSOptions == nil {
		container.HostConfig.DNSOptions = make([]string, 0)
	}
}

// UpdateMonitor updates monitor configure for running container
func (container *Container) UpdateMonitor(restartPolicy containertypes.RestartPolicy) {
	type policySetter interface {
		SetPolicy(containertypes.RestartPolicy)
	}

	if rm, ok := container.RestartManager().(policySetter); ok {
		rm.SetPolicy(restartPolicy)
	}
}

// FullHostname returns hostname and optional domain appended to it.
func (container *Container) FullHostname() string {
	fullHostname := container.Config.Hostname
	if container.Config.Domainname != "" {
		fullHostname = fmt.Sprintf("%s.%s", fullHostname, container.Config.Domainname)
	}
	return fullHostname
}

// RestartManager returns the current restartmanager instance connected to container.
func (container *Container) RestartManager() restartmanager.RestartManager {
	if container.restartManager == nil {
		container.restartManager = restartmanager.New(container.HostConfig.RestartPolicy, container.RestartCount)
	}
	return container.restartManager
}

// ResetRestartManager initializes new restartmanager based on container config
func (container *Container) ResetRestartManager(resetCount bool) {
	if container.restartManager != nil {
		container.restartManager.Cancel()
	}
	if resetCount {
		container.RestartCount = 0
	}
	container.restartManager = nil
}

type attachContext struct {
	ctx    context.Context
	cancel context.CancelFunc
	mu     sync.Mutex
}

// InitAttachContext initializes or returns existing context for attach calls to
// track container liveness.
func (container *Container) InitAttachContext() context.Context {
	container.attachContext.mu.Lock()
	defer container.attachContext.mu.Unlock()
	if container.attachContext.ctx == nil {
		container.attachContext.ctx, container.attachContext.cancel = context.WithCancel(context.Background())
	}
	return container.attachContext.ctx
}

// CancelAttachContext cancels attach context. All attach calls should detach
// after this call.
func (container *Container) CancelAttachContext() {
	container.attachContext.mu.Lock()
	if container.attachContext.ctx != nil {
		container.attachContext.cancel()
		container.attachContext.ctx = nil
	}
	container.attachContext.mu.Unlock()
}

func (container *Container) startLogging() error {
	if container.HostConfig.LogConfig.Type == "none" {
		return nil // do not start logging routines
	}

	l, err := container.StartLogger()
	if err != nil {
		return fmt.Errorf("failed to initialize logging driver: %v", err)
	}

	copier := logger.NewCopier(map[string]io.Reader{"stdout": container.StdoutPipe(), "stderr": container.StderrPipe()}, l)
	container.LogCopier = copier
	copier.Run()
	container.LogDriver = l

	return nil
}

// StdinPipe gets the stdin stream of the container
func (container *Container) StdinPipe() io.WriteCloser {
	return container.StreamConfig.StdinPipe()
}

// StdoutPipe gets the stdout stream of the container
func (container *Container) StdoutPipe() io.ReadCloser {
	return container.StreamConfig.StdoutPipe()
}

// StderrPipe gets the stderr stream of the container
func (container *Container) StderrPipe() io.ReadCloser {
	return container.StreamConfig.StderrPipe()
}

// CloseStreams closes the container's stdio streams
func (container *Container) CloseStreams() error {
	return container.StreamConfig.CloseStreams()
}

// InitializeStdio is called by libcontainerd to connect the stdio.
func (container *Container) InitializeStdio(iop *cio.DirectIO) (cio.IO, error) {
	if err := container.startLogging(); err != nil {
		container.Reset(false)
		return nil, err
	}

	container.StreamConfig.CopyToPipe(iop)

	if container.StreamConfig.Stdin() == nil && !container.Config.Tty {
		if iop.Stdin != nil {
			if err := iop.Stdin.Close(); err != nil {
				logrus.Warnf("error closing stdin: %+v", err)
			}
		}
	}

	return &rio{IO: iop, sc: container.StreamConfig}, nil
}

// MountsResourcePath returns the path where mounts are stored for the given mount
func (container *Container) MountsResourcePath(mount string) (string, error) {
	return container.GetRootResourcePath(filepath.Join("mounts", mount))
}

// SecretMountPath returns the path of the secret mount for the container
func (container *Container) SecretMountPath() (string, error) {
	return container.MountsResourcePath("secrets")
}

// SecretFilePath returns the path to the location of a secret on the host.
func (container *Container) SecretFilePath(secretRef swarmtypes.SecretReference) (string, error) {
	secrets, err := container.SecretMountPath()
	if err != nil {
		return "", err
	}
	return filepath.Join(secrets, secretRef.SecretID), nil
}

func getSecretTargetPath(r *swarmtypes.SecretReference) string {
	if filepath.IsAbs(r.File.Name) {
		return r.File.Name
	}

	return filepath.Join(containerSecretMountPath, r.File.Name)
}

// getConfigTargetPath makes sure that config paths inside the container are
// absolute, as required by the runtime spec, and enforced by runc >= 1.0.0-rc94.
// see https://github.com/opencontainers/runc/issues/2928
func getConfigTargetPath(r *swarmtypes.ConfigReference) string {
	if filepath.IsAbs(r.File.Name) {
		return r.File.Name
	}

	return filepath.Join(containerConfigMountPath, r.File.Name)
}

// CreateDaemonEnvironment creates a new environment variable slice for this container.
func (container *Container) CreateDaemonEnvironment(tty bool, linkedEnv []string) []string {
	// Setup environment
	ctrOS := container.OS
	if ctrOS == "" {
		ctrOS = runtime.GOOS
	}

	// Figure out what size slice we need so we can allocate this all at once.
	envSize := len(container.Config.Env)
	if runtime.GOOS != "windows" {
		envSize += 2 + len(linkedEnv)
	}
	if tty {
		envSize++
	}

	env := make([]string, 0, envSize)
	if runtime.GOOS != "windows" {
		env = append(env, "PATH="+system.DefaultPathEnv(ctrOS))
		env = append(env, "HOSTNAME="+container.Config.Hostname)
		if tty {
			env = append(env, "TERM=xterm")
		}
		env = append(env, linkedEnv...)
	}

	// because the env on the container can override certain default values
	// we need to replace the 'env' keys where they match and append anything
	// else.
	env = ReplaceOrAppendEnvValues(env, container.Config.Env)
	return env
}

type rio struct {
	cio.IO

	sc *stream.Config
}

func (i *rio) Close() error {
	i.IO.Close()

	return i.sc.CloseStreams()
}

func (i *rio) Wait() {
	i.sc.Wait(context.Background())

	i.IO.Wait()
}

Yeah I don't think we need it. Thanks!