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moby--moby/container.go
Alexander Larsson ab0f3f86c8 Avoid temporarily unmounting the container when restarting it
Stopping the container will typicall cause it to unmount, to keep it mounted
over the stop/start cycle we aquire a temporary reference to it during this time.

This helps with https://github.com/dotcloud/docker/issues/4036

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
2014-02-17 16:10:54 +01:00

1494 lines
38 KiB
Go

package docker
import (
"encoding/json"
"errors"
"fmt"
"github.com/dotcloud/docker/archive"
"github.com/dotcloud/docker/engine"
"github.com/dotcloud/docker/execdriver"
"github.com/dotcloud/docker/graphdriver"
"github.com/dotcloud/docker/nat"
"github.com/dotcloud/docker/pkg/mount"
"github.com/dotcloud/docker/pkg/term"
"github.com/dotcloud/docker/runconfig"
"github.com/dotcloud/docker/utils"
"github.com/kr/pty"
"io"
"io/ioutil"
"log"
"os"
"path"
"path/filepath"
"strings"
"sync"
"syscall"
"time"
)
var (
ErrNotATTY = errors.New("The PTY is not a file")
ErrNoTTY = errors.New("No PTY found")
)
type Container struct {
sync.Mutex
root string // Path to the "home" of the container, including metadata.
basefs string // Path to the graphdriver mountpoint
ID string
Created time.Time
Path string
Args []string
Config *runconfig.Config
State State
Image string
NetworkSettings *NetworkSettings
ResolvConfPath string
HostnamePath string
HostsPath string
Name string
Driver string
command *execdriver.Command
stdout *utils.WriteBroadcaster
stderr *utils.WriteBroadcaster
stdin io.ReadCloser
stdinPipe io.WriteCloser
ptyMaster io.Closer
runtime *Runtime
waitLock chan struct{}
Volumes map[string]string
// Store rw/ro in a separate structure to preserve reverse-compatibility on-disk.
// Easier than migrating older container configs :)
VolumesRW map[string]bool
hostConfig *runconfig.HostConfig
activeLinks map[string]*Link
}
type BindMap struct {
SrcPath string
DstPath string
Mode string
}
var (
ErrContainerStart = errors.New("The container failed to start. Unknown error")
ErrContainerStartTimeout = errors.New("The container failed to start due to timed out.")
)
// FIXME: move deprecated port stuff to nat to clean up the core.
type PortMapping map[string]string // Deprecated
type NetworkSettings struct {
IPAddress string
IPPrefixLen int
Gateway string
Bridge string
PortMapping map[string]PortMapping // Deprecated
Ports nat.PortMap
}
func (settings *NetworkSettings) PortMappingAPI() *engine.Table {
var outs = engine.NewTable("", 0)
for port, bindings := range settings.Ports {
p, _ := nat.ParsePort(port.Port())
if len(bindings) == 0 {
out := &engine.Env{}
out.SetInt("PublicPort", p)
out.Set("Type", port.Proto())
outs.Add(out)
continue
}
for _, binding := range bindings {
out := &engine.Env{}
h, _ := nat.ParsePort(binding.HostPort)
out.SetInt("PrivatePort", p)
out.SetInt("PublicPort", h)
out.Set("Type", port.Proto())
out.Set("IP", binding.HostIp)
outs.Add(out)
}
}
return outs
}
// Inject the io.Reader at the given path. Note: do not close the reader
func (container *Container) Inject(file io.Reader, pth string) error {
if err := container.Mount(); err != nil {
return fmt.Errorf("inject: error mounting container %s: %s", container.ID, err)
}
defer container.Unmount()
// Return error if path exists
destPath := path.Join(container.basefs, pth)
if _, err := os.Stat(destPath); err == nil {
// Since err is nil, the path could be stat'd and it exists
return fmt.Errorf("%s exists", pth)
} else if !os.IsNotExist(err) {
// Expect err might be that the file doesn't exist, so
// if it's some other error, return that.
return err
}
// Make sure the directory exists
if err := os.MkdirAll(path.Join(container.basefs, path.Dir(pth)), 0755); err != nil {
return err
}
dest, err := os.Create(destPath)
if err != nil {
return err
}
defer dest.Close()
if _, err := io.Copy(dest, file); err != nil {
return err
}
return nil
}
func (container *Container) When() time.Time {
return container.Created
}
func (container *Container) FromDisk() error {
data, err := ioutil.ReadFile(container.jsonPath())
if err != nil {
return err
}
// Load container settings
// udp broke compat of docker.PortMapping, but it's not used when loading a container, we can skip it
if err := json.Unmarshal(data, container); err != nil && !strings.Contains(err.Error(), "docker.PortMapping") {
return err
}
return container.readHostConfig()
}
func (container *Container) ToDisk() (err error) {
data, err := json.Marshal(container)
if err != nil {
return
}
err = ioutil.WriteFile(container.jsonPath(), data, 0666)
if err != nil {
return
}
return container.writeHostConfig()
}
func (container *Container) readHostConfig() error {
container.hostConfig = &runconfig.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.)
_, err := os.Stat(container.hostConfigPath())
if os.IsNotExist(err) {
return nil
}
data, err := ioutil.ReadFile(container.hostConfigPath())
if err != nil {
return err
}
return json.Unmarshal(data, container.hostConfig)
}
func (container *Container) writeHostConfig() (err error) {
data, err := json.Marshal(container.hostConfig)
if err != nil {
return
}
return ioutil.WriteFile(container.hostConfigPath(), data, 0666)
}
func (container *Container) generateEnvConfig(env []string) error {
data, err := json.Marshal(env)
if err != nil {
return err
}
p, err := container.EnvConfigPath()
if err != nil {
return err
}
ioutil.WriteFile(p, data, 0600)
return nil
}
func (container *Container) setupPty() error {
ptyMaster, ptySlave, err := pty.Open()
if err != nil {
return err
}
container.ptyMaster = ptyMaster
container.command.Stdout = ptySlave
container.command.Stderr = ptySlave
container.command.Console = ptySlave.Name()
// Copy the PTYs to our broadcasters
go func() {
defer container.stdout.CloseWriters()
utils.Debugf("startPty: begin of stdout pipe")
io.Copy(container.stdout, ptyMaster)
utils.Debugf("startPty: end of stdout pipe")
}()
// stdin
if container.Config.OpenStdin {
container.command.Stdin = ptySlave
container.command.SysProcAttr.Setctty = true
go func() {
defer container.stdin.Close()
utils.Debugf("startPty: begin of stdin pipe")
io.Copy(ptyMaster, container.stdin)
utils.Debugf("startPty: end of stdin pipe")
}()
}
return nil
}
func (container *Container) setupStd() error {
container.command.Stdout = container.stdout
container.command.Stderr = container.stderr
if container.Config.OpenStdin {
stdin, err := container.command.StdinPipe()
if err != nil {
return err
}
go func() {
defer stdin.Close()
utils.Debugf("start: begin of stdin pipe")
io.Copy(stdin, container.stdin)
utils.Debugf("start: end of stdin pipe")
}()
}
return nil
}
func (container *Container) Attach(stdin io.ReadCloser, stdinCloser io.Closer, stdout io.Writer, stderr io.Writer) chan error {
var cStdout, cStderr io.ReadCloser
var nJobs int
errors := make(chan error, 3)
if stdin != nil && container.Config.OpenStdin {
nJobs += 1
if cStdin, err := container.StdinPipe(); err != nil {
errors <- err
} else {
go func() {
utils.Debugf("attach: stdin: begin")
defer utils.Debugf("attach: stdin: end")
// No matter what, when stdin is closed (io.Copy unblock), close stdout and stderr
if container.Config.StdinOnce && !container.Config.Tty {
defer cStdin.Close()
} else {
defer func() {
if cStdout != nil {
cStdout.Close()
}
if cStderr != nil {
cStderr.Close()
}
}()
}
if container.Config.Tty {
_, err = utils.CopyEscapable(cStdin, stdin)
} else {
_, err = io.Copy(cStdin, stdin)
}
if err == io.ErrClosedPipe {
err = nil
}
if err != nil {
utils.Errorf("attach: stdin: %s", err)
}
errors <- err
}()
}
}
if stdout != nil {
nJobs += 1
if p, err := container.StdoutPipe(); err != nil {
errors <- err
} else {
cStdout = p
go func() {
utils.Debugf("attach: stdout: begin")
defer utils.Debugf("attach: stdout: end")
// If we are in StdinOnce mode, then close stdin
if container.Config.StdinOnce && stdin != nil {
defer stdin.Close()
}
if stdinCloser != nil {
defer stdinCloser.Close()
}
_, err := io.Copy(stdout, cStdout)
if err == io.ErrClosedPipe {
err = nil
}
if err != nil {
utils.Errorf("attach: stdout: %s", err)
}
errors <- err
}()
}
} else {
go func() {
if stdinCloser != nil {
defer stdinCloser.Close()
}
if cStdout, err := container.StdoutPipe(); err != nil {
utils.Errorf("attach: stdout pipe: %s", err)
} else {
io.Copy(&utils.NopWriter{}, cStdout)
}
}()
}
if stderr != nil {
nJobs += 1
if p, err := container.StderrPipe(); err != nil {
errors <- err
} else {
cStderr = p
go func() {
utils.Debugf("attach: stderr: begin")
defer utils.Debugf("attach: stderr: end")
// If we are in StdinOnce mode, then close stdin
if container.Config.StdinOnce && stdin != nil {
defer stdin.Close()
}
if stdinCloser != nil {
defer stdinCloser.Close()
}
_, err := io.Copy(stderr, cStderr)
if err == io.ErrClosedPipe {
err = nil
}
if err != nil {
utils.Errorf("attach: stderr: %s", err)
}
errors <- err
}()
}
} else {
go func() {
if stdinCloser != nil {
defer stdinCloser.Close()
}
if cStderr, err := container.StderrPipe(); err != nil {
utils.Errorf("attach: stdout pipe: %s", err)
} else {
io.Copy(&utils.NopWriter{}, cStderr)
}
}()
}
return utils.Go(func() error {
defer func() {
if cStdout != nil {
cStdout.Close()
}
if cStderr != nil {
cStderr.Close()
}
}()
// FIXME: how to clean up the stdin goroutine without the unwanted side effect
// of closing the passed stdin? Add an intermediary io.Pipe?
for i := 0; i < nJobs; i += 1 {
utils.Debugf("attach: waiting for job %d/%d", i+1, nJobs)
if err := <-errors; err != nil {
utils.Errorf("attach: job %d returned error %s, aborting all jobs", i+1, err)
return err
}
utils.Debugf("attach: job %d completed successfully", i+1)
}
utils.Debugf("attach: all jobs completed successfully")
return nil
})
}
func populateCommand(c *Container) {
var (
en *execdriver.Network
driverConfig []string
)
if !c.Config.NetworkDisabled {
network := c.NetworkSettings
en = &execdriver.Network{
Gateway: network.Gateway,
Bridge: network.Bridge,
IPAddress: network.IPAddress,
IPPrefixLen: network.IPPrefixLen,
Mtu: c.runtime.config.Mtu,
}
}
if lxcConf := c.hostConfig.LxcConf; lxcConf != nil {
for _, pair := range lxcConf {
driverConfig = append(driverConfig, fmt.Sprintf("%s = %s", pair.Key, pair.Value))
}
}
resources := &execdriver.Resources{
Memory: c.Config.Memory,
MemorySwap: c.Config.MemorySwap,
CpuShares: c.Config.CpuShares,
}
c.command = &execdriver.Command{
ID: c.ID,
Privileged: c.hostConfig.Privileged,
Rootfs: c.RootfsPath(),
InitPath: "/.dockerinit",
Entrypoint: c.Path,
Arguments: c.Args,
WorkingDir: c.Config.WorkingDir,
Network: en,
Tty: c.Config.Tty,
User: c.Config.User,
Config: driverConfig,
Resources: resources,
}
c.command.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
}
func (container *Container) Start() (err error) {
container.Lock()
defer container.Unlock()
if container.State.IsRunning() {
return fmt.Errorf("The container %s is already running.", container.ID)
}
defer func() {
if err != nil {
container.cleanup()
}
}()
if err := container.Mount(); err != nil {
return err
}
if container.runtime.config.DisableNetwork {
container.Config.NetworkDisabled = true
container.buildHostnameAndHostsFiles("127.0.1.1")
} else {
if err := container.allocateNetwork(); err != nil {
return err
}
container.buildHostnameAndHostsFiles(container.NetworkSettings.IPAddress)
}
// Make sure the config is compatible with the current kernel
if container.Config.Memory > 0 && !container.runtime.sysInfo.MemoryLimit {
log.Printf("WARNING: Your kernel does not support memory limit capabilities. Limitation discarded.\n")
container.Config.Memory = 0
}
if container.Config.Memory > 0 && !container.runtime.sysInfo.SwapLimit {
log.Printf("WARNING: Your kernel does not support swap limit capabilities. Limitation discarded.\n")
container.Config.MemorySwap = -1
}
if container.runtime.sysInfo.IPv4ForwardingDisabled {
log.Printf("WARNING: IPv4 forwarding is disabled. Networking will not work")
}
if container.Volumes == nil || len(container.Volumes) == 0 {
container.Volumes = make(map[string]string)
container.VolumesRW = make(map[string]bool)
}
// Apply volumes from another container if requested
if err := container.applyExternalVolumes(); err != nil {
return err
}
if err := container.createVolumes(); err != nil {
return err
}
// Setup environment
env := []string{
"HOME=/",
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"HOSTNAME=" + container.Config.Hostname,
}
if container.Config.Tty {
env = append(env, "TERM=xterm")
}
// Init any links between the parent and children
runtime := container.runtime
children, err := runtime.Children(container.Name)
if err != nil {
return err
}
if len(children) > 0 {
container.activeLinks = make(map[string]*Link, len(children))
// If we encounter an error make sure that we rollback any network
// config and ip table changes
rollback := func() {
for _, link := range container.activeLinks {
link.Disable()
}
container.activeLinks = nil
}
for p, child := range children {
link, err := NewLink(container, child, p, runtime.eng)
if err != nil {
rollback()
return err
}
container.activeLinks[link.Alias()] = link
if err := link.Enable(); err != nil {
rollback()
return err
}
for _, envVar := range link.ToEnv() {
env = append(env, envVar)
}
}
}
for _, elem := range container.Config.Env {
env = append(env, elem)
}
if err := container.generateEnvConfig(env); err != nil {
return err
}
if container.Config.WorkingDir != "" {
container.Config.WorkingDir = path.Clean(container.Config.WorkingDir)
if err := os.MkdirAll(path.Join(container.basefs, container.Config.WorkingDir), 0755); err != nil {
return nil
}
}
envPath, err := container.EnvConfigPath()
if err != nil {
return err
}
// Setup the root fs as a bind mount of the base fs
root := container.RootfsPath()
if err := os.MkdirAll(root, 0755); err != nil && !os.IsExist(err) {
return nil
}
// Create a bind mount of the base fs as a place where we can add mounts
// without affecting the ability to access the base fs
if err := mount.Mount(container.basefs, root, "none", "bind,rw"); err != nil {
return err
}
// Make sure the root fs is private so the mounts here don't propagate to basefs
if err := mount.ForceMount(root, root, "none", "private"); err != nil {
return err
}
// Mount docker specific files into the containers root fs
if err := mount.Mount(runtime.sysInitPath, path.Join(root, "/.dockerinit"), "none", "bind,ro"); err != nil {
return err
}
if err := mount.Mount(envPath, path.Join(root, "/.dockerenv"), "none", "bind,ro"); err != nil {
return err
}
if err := mount.Mount(container.ResolvConfPath, path.Join(root, "/etc/resolv.conf"), "none", "bind,ro"); err != nil {
return err
}
if container.HostnamePath != "" && container.HostsPath != "" {
if err := mount.Mount(container.HostnamePath, path.Join(root, "/etc/hostname"), "none", "bind,ro"); err != nil {
return err
}
if err := mount.Mount(container.HostsPath, path.Join(root, "/etc/hosts"), "none", "bind,ro"); err != nil {
return err
}
}
// Mount user specified volumes
for r, v := range container.Volumes {
mountAs := "ro"
if container.VolumesRW[r] {
mountAs = "rw"
}
r = path.Join(root, r)
if p, err := utils.FollowSymlinkInScope(r, root); err != nil {
return err
} else {
r = p
}
if err := mount.Mount(v, r, "none", fmt.Sprintf("bind,%s", mountAs)); err != nil {
return err
}
}
populateCommand(container)
// Setup logging of stdout and stderr to disk
if err := container.runtime.LogToDisk(container.stdout, container.logPath("json"), "stdout"); err != nil {
return err
}
if err := container.runtime.LogToDisk(container.stderr, container.logPath("json"), "stderr"); err != nil {
return err
}
container.waitLock = make(chan struct{})
// Setuping pipes and/or Pty
var setup func() error
if container.Config.Tty {
setup = container.setupPty
} else {
setup = container.setupStd
}
if err := setup(); err != nil {
return err
}
callbackLock := make(chan struct{})
callback := func(command *execdriver.Command) {
container.State.SetRunning(command.Pid())
if command.Tty {
// The callback is called after the process Start()
// so we are in the parent process. In TTY mode, stdin/out/err is the PtySlace
// which we close here.
if c, ok := command.Stdout.(io.Closer); ok {
c.Close()
}
}
if err := container.ToDisk(); err != nil {
utils.Debugf("%s", err)
}
close(callbackLock)
}
// We use a callback here instead of a goroutine and an chan for
// syncronization purposes
cErr := utils.Go(func() error { return container.monitor(callback) })
// Start should not return until the process is actually running
select {
case <-callbackLock:
case err := <-cErr:
return err
}
return nil
}
func (container *Container) getBindMap() (map[string]BindMap, error) {
// Create the requested bind mounts
binds := make(map[string]BindMap)
// Define illegal container destinations
illegalDsts := []string{"/", "."}
for _, bind := range container.hostConfig.Binds {
// FIXME: factorize bind parsing in parseBind
var src, dst, mode string
arr := strings.Split(bind, ":")
if len(arr) == 2 {
src = arr[0]
dst = arr[1]
mode = "rw"
} else if len(arr) == 3 {
src = arr[0]
dst = arr[1]
mode = arr[2]
} else {
return nil, fmt.Errorf("Invalid bind specification: %s", bind)
}
// Bail if trying to mount to an illegal destination
for _, illegal := range illegalDsts {
if dst == illegal {
return nil, fmt.Errorf("Illegal bind destination: %s", dst)
}
}
bindMap := BindMap{
SrcPath: src,
DstPath: dst,
Mode: mode,
}
binds[path.Clean(dst)] = bindMap
}
return binds, nil
}
func (container *Container) createVolumes() error {
binds, err := container.getBindMap()
if err != nil {
return err
}
volumesDriver := container.runtime.volumes.driver
// Create the requested volumes if they don't exist
for volPath := range container.Config.Volumes {
volPath = path.Clean(volPath)
volIsDir := true
// Skip existing volumes
if _, exists := container.Volumes[volPath]; exists {
continue
}
var srcPath string
var isBindMount bool
srcRW := false
// If an external bind is defined for this volume, use that as a source
if bindMap, exists := binds[volPath]; exists {
isBindMount = true
srcPath = bindMap.SrcPath
if strings.ToLower(bindMap.Mode) == "rw" {
srcRW = true
}
if stat, err := os.Stat(bindMap.SrcPath); err != nil {
return err
} else {
volIsDir = stat.IsDir()
}
// Otherwise create an directory in $ROOT/volumes/ and use that
} else {
// Do not pass a container as the parameter for the volume creation.
// The graph driver using the container's information ( Image ) to
// create the parent.
c, err := container.runtime.volumes.Create(nil, nil, "", "", nil)
if err != nil {
return err
}
srcPath, err = volumesDriver.Get(c.ID)
if err != nil {
return fmt.Errorf("Driver %s failed to get volume rootfs %s: %s", volumesDriver, c.ID, err)
}
srcRW = true // RW by default
}
if p, err := filepath.EvalSymlinks(srcPath); err != nil {
return err
} else {
srcPath = p
}
container.Volumes[volPath] = srcPath
container.VolumesRW[volPath] = srcRW
// Create the mountpoint
volPath = path.Join(container.basefs, volPath)
rootVolPath, err := utils.FollowSymlinkInScope(volPath, container.basefs)
if err != nil {
return err
}
if _, err := os.Stat(rootVolPath); err != nil {
if os.IsNotExist(err) {
if volIsDir {
if err := os.MkdirAll(rootVolPath, 0755); err != nil {
return err
}
} else {
if err := os.MkdirAll(path.Dir(rootVolPath), 0755); err != nil {
return err
}
if f, err := os.OpenFile(rootVolPath, os.O_CREATE, 0755); err != nil {
return err
} else {
f.Close()
}
}
}
}
// Do not copy or change permissions if we are mounting from the host
if srcRW && !isBindMount {
volList, err := ioutil.ReadDir(rootVolPath)
if err != nil {
return err
}
if len(volList) > 0 {
srcList, err := ioutil.ReadDir(srcPath)
if err != nil {
return err
}
if len(srcList) == 0 {
// If the source volume is empty copy files from the root into the volume
if err := archive.CopyWithTar(rootVolPath, srcPath); err != nil {
return err
}
var stat syscall.Stat_t
if err := syscall.Stat(rootVolPath, &stat); err != nil {
return err
}
var srcStat syscall.Stat_t
if err := syscall.Stat(srcPath, &srcStat); err != nil {
return err
}
// Change the source volume's ownership if it differs from the root
// files that were just copied
if stat.Uid != srcStat.Uid || stat.Gid != srcStat.Gid {
if err := os.Chown(srcPath, int(stat.Uid), int(stat.Gid)); err != nil {
return err
}
}
}
}
}
}
return nil
}
func (container *Container) applyExternalVolumes() error {
if container.Config.VolumesFrom != "" {
containerSpecs := strings.Split(container.Config.VolumesFrom, ",")
for _, containerSpec := range containerSpecs {
mountRW := true
specParts := strings.SplitN(containerSpec, ":", 2)
switch len(specParts) {
case 0:
return fmt.Errorf("Malformed volumes-from specification: %s", container.Config.VolumesFrom)
case 2:
switch specParts[1] {
case "ro":
mountRW = false
case "rw": // mountRW is already true
default:
return fmt.Errorf("Malformed volumes-from specification: %s", containerSpec)
}
}
c := container.runtime.Get(specParts[0])
if c == nil {
return fmt.Errorf("Container %s not found. Impossible to mount its volumes", container.ID)
}
for volPath, id := range c.Volumes {
if _, exists := container.Volumes[volPath]; exists {
continue
}
if err := os.MkdirAll(path.Join(container.basefs, volPath), 0755); err != nil {
return err
}
container.Volumes[volPath] = id
if isRW, exists := c.VolumesRW[volPath]; exists {
container.VolumesRW[volPath] = isRW && mountRW
}
}
}
}
return nil
}
func (container *Container) Run() error {
if err := container.Start(); err != nil {
return err
}
container.Wait()
return nil
}
func (container *Container) Output() (output []byte, err error) {
pipe, err := container.StdoutPipe()
if err != nil {
return nil, err
}
defer pipe.Close()
if err := container.Start(); err != nil {
return nil, err
}
output, err = ioutil.ReadAll(pipe)
container.Wait()
return output, err
}
// Container.StdinPipe returns a WriteCloser which can be used to feed data
// to the standard input of the container's active process.
// Container.StdoutPipe and Container.StderrPipe each return a ReadCloser
// which can be used to retrieve the standard output (and error) generated
// by the container's active process. The output (and error) are actually
// copied and delivered to all StdoutPipe and StderrPipe consumers, using
// a kind of "broadcaster".
func (container *Container) StdinPipe() (io.WriteCloser, error) {
return container.stdinPipe, nil
}
func (container *Container) StdoutPipe() (io.ReadCloser, error) {
reader, writer := io.Pipe()
container.stdout.AddWriter(writer, "")
return utils.NewBufReader(reader), nil
}
func (container *Container) StderrPipe() (io.ReadCloser, error) {
reader, writer := io.Pipe()
container.stderr.AddWriter(writer, "")
return utils.NewBufReader(reader), nil
}
func (container *Container) buildHostnameAndHostsFiles(IP string) {
container.HostnamePath = path.Join(container.root, "hostname")
ioutil.WriteFile(container.HostnamePath, []byte(container.Config.Hostname+"\n"), 0644)
hostsContent := []byte(`
127.0.0.1 localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
`)
container.HostsPath = path.Join(container.root, "hosts")
if container.Config.Domainname != "" {
hostsContent = append([]byte(fmt.Sprintf("%s\t%s.%s %s\n", IP, container.Config.Hostname, container.Config.Domainname, container.Config.Hostname)), hostsContent...)
} else if !container.Config.NetworkDisabled {
hostsContent = append([]byte(fmt.Sprintf("%s\t%s\n", IP, container.Config.Hostname)), hostsContent...)
}
ioutil.WriteFile(container.HostsPath, hostsContent, 0644)
}
func (container *Container) allocateNetwork() error {
if container.Config.NetworkDisabled {
return nil
}
var (
env *engine.Env
err error
eng = container.runtime.eng
)
if container.State.IsGhost() {
if container.runtime.config.DisableNetwork {
env = &engine.Env{}
} else {
currentIP := container.NetworkSettings.IPAddress
job := eng.Job("allocate_interface", container.ID)
if currentIP != "" {
job.Setenv("RequestIP", currentIP)
}
env, err = job.Stdout.AddEnv()
if err != nil {
return err
}
if err := job.Run(); err != nil {
return err
}
}
} else {
job := eng.Job("allocate_interface", container.ID)
env, err = job.Stdout.AddEnv()
if err != nil {
return err
}
if err := job.Run(); err != nil {
return err
}
}
if container.Config.PortSpecs != nil {
utils.Debugf("Migrating port mappings for container: %s", strings.Join(container.Config.PortSpecs, ", "))
if err := migratePortMappings(container.Config, container.hostConfig); err != nil {
return err
}
container.Config.PortSpecs = nil
if err := container.writeHostConfig(); err != nil {
return err
}
}
var (
portSpecs = make(nat.PortSet)
bindings = make(nat.PortMap)
)
if !container.State.IsGhost() {
if container.Config.ExposedPorts != nil {
portSpecs = container.Config.ExposedPorts
}
if container.hostConfig.PortBindings != nil {
bindings = container.hostConfig.PortBindings
}
} else {
if container.NetworkSettings.Ports != nil {
for port, binding := range container.NetworkSettings.Ports {
portSpecs[port] = struct{}{}
bindings[port] = binding
}
}
}
container.NetworkSettings.PortMapping = nil
for port := range portSpecs {
binding := bindings[port]
if container.hostConfig.PublishAllPorts && len(binding) == 0 {
binding = append(binding, nat.PortBinding{})
}
for i := 0; i < len(binding); i++ {
b := binding[i]
portJob := eng.Job("allocate_port", container.ID)
portJob.Setenv("HostIP", b.HostIp)
portJob.Setenv("HostPort", b.HostPort)
portJob.Setenv("Proto", port.Proto())
portJob.Setenv("ContainerPort", port.Port())
portEnv, err := portJob.Stdout.AddEnv()
if err != nil {
return err
}
if err := portJob.Run(); err != nil {
eng.Job("release_interface", container.ID).Run()
return err
}
b.HostIp = portEnv.Get("HostIP")
b.HostPort = portEnv.Get("HostPort")
binding[i] = b
}
bindings[port] = binding
}
container.writeHostConfig()
container.NetworkSettings.Ports = bindings
container.NetworkSettings.Bridge = env.Get("Bridge")
container.NetworkSettings.IPAddress = env.Get("IP")
container.NetworkSettings.IPPrefixLen = env.GetInt("IPPrefixLen")
container.NetworkSettings.Gateway = env.Get("Gateway")
return nil
}
func (container *Container) releaseNetwork() {
if container.Config.NetworkDisabled {
return
}
eng := container.runtime.eng
eng.Job("release_interface", container.ID).Run()
container.NetworkSettings = &NetworkSettings{}
}
func (container *Container) monitor(callback execdriver.StartCallback) error {
var (
err error
exitCode int
)
if container.command == nil {
// This happends when you have a GHOST container with lxc
populateCommand(container)
err = container.runtime.RestoreCommand(container)
} else {
exitCode, err = container.runtime.Run(container, callback)
}
if err != nil {
utils.Errorf("Error running container: %s", err)
}
// Cleanup
container.cleanup()
// Re-create a brand new stdin pipe once the container exited
if container.Config.OpenStdin {
container.stdin, container.stdinPipe = io.Pipe()
}
container.State.SetStopped(exitCode)
if container.runtime != nil && container.runtime.srv != nil {
container.runtime.srv.LogEvent("die", container.ID, container.runtime.repositories.ImageName(container.Image))
}
close(container.waitLock)
// FIXME: there is a race condition here which causes this to fail during the unit tests.
// If another goroutine was waiting for Wait() to return before removing the container's root
// from the filesystem... At this point it may already have done so.
// This is because State.setStopped() has already been called, and has caused Wait()
// to return.
// FIXME: why are we serializing running state to disk in the first place?
//log.Printf("%s: Failed to dump configuration to the disk: %s", container.ID, err)
container.ToDisk()
return err
}
func (container *Container) cleanup() {
container.releaseNetwork()
// Disable all active links
if container.activeLinks != nil {
for _, link := range container.activeLinks {
link.Disable()
}
}
if container.Config.OpenStdin {
if err := container.stdin.Close(); err != nil {
utils.Errorf("%s: Error close stdin: %s", container.ID, err)
}
}
if err := container.stdout.CloseWriters(); err != nil {
utils.Errorf("%s: Error close stdout: %s", container.ID, err)
}
if err := container.stderr.CloseWriters(); err != nil {
utils.Errorf("%s: Error close stderr: %s", container.ID, err)
}
if container.ptyMaster != nil {
if err := container.ptyMaster.Close(); err != nil {
utils.Errorf("%s: Error closing Pty master: %s", container.ID, err)
}
}
var (
root = container.RootfsPath()
mounts = []string{
root,
path.Join(root, "/.dockerinit"),
path.Join(root, "/.dockerenv"),
path.Join(root, "/etc/resolv.conf"),
}
)
if container.HostnamePath != "" && container.HostsPath != "" {
mounts = append(mounts, path.Join(root, "/etc/hostname"), path.Join(root, "/etc/hosts"))
}
for r := range container.Volumes {
mounts = append(mounts, path.Join(root, r))
}
for i := len(mounts) - 1; i >= 0; i-- {
if lastError := mount.Unmount(mounts[i]); lastError != nil {
log.Printf("Failed to umount %v: %v", mounts[i], lastError)
}
}
if err := container.Unmount(); err != nil {
log.Printf("%v: Failed to umount filesystem: %v", container.ID, err)
}
}
func (container *Container) kill(sig int) error {
container.Lock()
defer container.Unlock()
if !container.State.IsRunning() {
return nil
}
return container.runtime.Kill(container, sig)
}
func (container *Container) Kill() error {
if !container.State.IsRunning() {
return nil
}
// 1. Send SIGKILL
if err := container.kill(9); err != nil {
return err
}
// 2. Wait for the process to die, in last resort, try to kill the process directly
if err := container.WaitTimeout(10 * time.Second); err != nil {
if container.command == nil {
return fmt.Errorf("lxc-kill failed, impossible to kill the container %s", utils.TruncateID(container.ID))
}
log.Printf("Container %s failed to exit within 10 seconds of lxc-kill %s - trying direct SIGKILL", "SIGKILL", utils.TruncateID(container.ID))
if err := container.runtime.Kill(container, 9); err != nil {
return err
}
}
container.Wait()
return nil
}
func (container *Container) Stop(seconds int) error {
if !container.State.IsRunning() {
return nil
}
// 1. Send a SIGTERM
if err := container.kill(15); err != nil {
utils.Debugf("Error sending kill SIGTERM: %s", err)
log.Print("Failed to send SIGTERM to the process, force killing")
if err := container.kill(9); err != nil {
return err
}
}
// 2. Wait for the process to exit on its own
if err := container.WaitTimeout(time.Duration(seconds) * time.Second); err != nil {
log.Printf("Container %v failed to exit within %d seconds of SIGTERM - using the force", container.ID, seconds)
// 3. If it doesn't, then send SIGKILL
if err := container.Kill(); err != nil {
return err
}
}
return nil
}
func (container *Container) Restart(seconds int) error {
// Avoid unnecessarily unmounting and then directly mounting
// the container when the container stops and then starts
// again
if err := container.Mount(); err == nil {
defer container.Unmount()
}
if err := container.Stop(seconds); err != nil {
return err
}
return container.Start()
}
// Wait blocks until the container stops running, then returns its exit code.
func (container *Container) Wait() int {
<-container.waitLock
return container.State.GetExitCode()
}
func (container *Container) Resize(h, w int) error {
pty, ok := container.ptyMaster.(*os.File)
if !ok {
return fmt.Errorf("ptyMaster does not have Fd() method")
}
return term.SetWinsize(pty.Fd(), &term.Winsize{Height: uint16(h), Width: uint16(w)})
}
func (container *Container) ExportRw() (archive.Archive, error) {
if err := container.Mount(); err != nil {
return nil, err
}
if container.runtime == nil {
return nil, fmt.Errorf("Can't load storage driver for unregistered container %s", container.ID)
}
archive, err := container.runtime.Diff(container)
if err != nil {
container.Unmount()
return nil, err
}
return utils.NewReadCloserWrapper(archive, func() error {
err := archive.Close()
container.Unmount()
return err
}), nil
}
func (container *Container) Export() (archive.Archive, error) {
if err := container.Mount(); err != nil {
return nil, err
}
archive, err := archive.Tar(container.basefs, archive.Uncompressed)
if err != nil {
container.Unmount()
return nil, err
}
return utils.NewReadCloserWrapper(archive, func() error {
err := archive.Close()
container.Unmount()
return err
}), nil
}
func (container *Container) WaitTimeout(timeout time.Duration) error {
done := make(chan bool)
go func() {
container.Wait()
done <- true
}()
select {
case <-time.After(timeout):
return fmt.Errorf("Timed Out")
case <-done:
return nil
}
}
func (container *Container) Mount() error {
return container.runtime.Mount(container)
}
func (container *Container) Changes() ([]archive.Change, error) {
return container.runtime.Changes(container)
}
func (container *Container) GetImage() (*Image, error) {
if container.runtime == nil {
return nil, fmt.Errorf("Can't get image of unregistered container")
}
return container.runtime.graph.Get(container.Image)
}
func (container *Container) Unmount() error {
return container.runtime.Unmount(container)
}
func (container *Container) logPath(name string) string {
return path.Join(container.root, fmt.Sprintf("%s-%s.log", container.ID, name))
}
func (container *Container) ReadLog(name string) (io.Reader, error) {
return os.Open(container.logPath(name))
}
func (container *Container) hostConfigPath() string {
return path.Join(container.root, "hostconfig.json")
}
func (container *Container) jsonPath() string {
return path.Join(container.root, "config.json")
}
func (container *Container) EnvConfigPath() (string, error) {
p := path.Join(container.root, "config.env")
if _, err := os.Stat(p); err != nil {
if os.IsNotExist(err) {
f, err := os.Create(p)
if err != nil {
return "", err
}
f.Close()
} else {
return "", err
}
}
return p, nil
}
// This method must be exported to be used from the lxc template
// This directory is only usable when the container is running
func (container *Container) RootfsPath() string {
return path.Join(container.root, "root")
}
// This is the stand-alone version of the root fs, without any additional mounts.
// This directory is usable whenever the container is mounted (and not unmounted)
func (container *Container) BasefsPath() string {
return container.basefs
}
func validateID(id string) error {
if id == "" {
return fmt.Errorf("Invalid empty id")
}
return nil
}
// GetSize, return real size, virtual size
func (container *Container) GetSize() (int64, int64) {
var (
sizeRw, sizeRootfs int64
err error
driver = container.runtime.driver
)
if err := container.Mount(); err != nil {
utils.Errorf("Warning: failed to compute size of container rootfs %s: %s", container.ID, err)
return sizeRw, sizeRootfs
}
defer container.Unmount()
if differ, ok := container.runtime.driver.(graphdriver.Differ); ok {
sizeRw, err = differ.DiffSize(container.ID)
if err != nil {
utils.Errorf("Warning: driver %s couldn't return diff size of container %s: %s", driver, container.ID, err)
// FIXME: GetSize should return an error. Not changing it now in case
// there is a side-effect.
sizeRw = -1
}
} else {
changes, _ := container.Changes()
if changes != nil {
sizeRw = archive.ChangesSize(container.basefs, changes)
} else {
sizeRw = -1
}
}
if _, err = os.Stat(container.basefs); err != nil {
if sizeRootfs, err = utils.TreeSize(container.basefs); err != nil {
sizeRootfs = -1
}
}
return sizeRw, sizeRootfs
}
func (container *Container) Copy(resource string) (io.ReadCloser, error) {
if err := container.Mount(); err != nil {
return nil, err
}
var filter []string
basePath := path.Join(container.basefs, resource)
stat, err := os.Stat(basePath)
if err != nil {
container.Unmount()
return nil, err
}
if !stat.IsDir() {
d, f := path.Split(basePath)
basePath = d
filter = []string{f}
} else {
filter = []string{path.Base(basePath)}
basePath = path.Dir(basePath)
}
archive, err := archive.TarFilter(basePath, &archive.TarOptions{
Compression: archive.Uncompressed,
Includes: filter,
})
if err != nil {
return nil, err
}
return utils.NewReadCloserWrapper(archive, func() error {
err := archive.Close()
container.Unmount()
return err
}), nil
}
// Returns true if the container exposes a certain port
func (container *Container) Exposes(p nat.Port) bool {
_, exists := container.Config.ExposedPorts[p]
return exists
}
func (container *Container) GetPtyMaster() (*os.File, error) {
if container.ptyMaster == nil {
return nil, ErrNoTTY
}
if pty, ok := container.ptyMaster.(*os.File); ok {
return pty, nil
}
return nil, ErrNotATTY
}