package docker
import (
"encoding/json"
"errors"
"fmt"
"github.com/dotcloud/docker/rcli"
"github.com/kr/pty"
"io"
"io/ioutil"
"log"
"os"
"os/exec"
"path"
"strconv"
"syscall"
"time"
)
type Container struct {
root string
Id string
Created time.Time
Path string
Args []string
Config *Config
State State
Image string
network *NetworkInterface
NetworkSettings *NetworkSettings
SysInitPath string
cmd *exec.Cmd
stdout *writeBroadcaster
stderr *writeBroadcaster
stdin io.ReadCloser
stdinPipe io.WriteCloser
stdoutLog *os.File
stderrLog *os.File
runtime *Runtime
}
type Config struct {
Hostname string
User string
Memory int64 // Memory limit (in bytes)
MemorySwap int64 // Total memory usage (memory + swap); set `-1' to disable swap
Detach bool
Ports []int
Tty bool // Attach standard streams to a tty, including stdin if it is not closed.
OpenStdin bool // Open stdin
Env []string
Cmd []string
Image string // Name of the image as it was passed by the operator (eg. could be symbolic)
}
func ParseRun(args []string, stdout io.Writer) (*Config, error) {
cmd := rcli.Subcmd(stdout, "run", "[OPTIONS] IMAGE COMMAND [ARG...]", "Run a command in a new container")
if len(args) > 0 && args[0] != "--help" {
cmd.SetOutput(ioutil.Discard)
}
flUser := cmd.String("u", "", "Username or UID")
flDetach := cmd.Bool("d", false, "Detached mode: leave the container running in the background")
flStdin := cmd.Bool("i", false, "Keep stdin open even if not attached")
flTty := cmd.Bool("t", false, "Allocate a pseudo-tty")
flMemory := cmd.Int64("m", 0, "Memory limit (in bytes)")
var flPorts ports
cmd.Var(&flPorts, "p", "Map a network port to the container")
var flEnv ListOpts
cmd.Var(&flEnv, "e", "Set environment variables")
if err := cmd.Parse(args); err != nil {
return nil, err
}
parsedArgs := cmd.Args()
runCmd := []string{}
image := ""
if len(parsedArgs) >= 1 {
image = cmd.Arg(0)
}
if len(parsedArgs) > 1 {
runCmd = parsedArgs[1:]
}
config := &Config{
Ports: flPorts,
User: *flUser,
Tty: *flTty,
OpenStdin: *flStdin,
Memory: *flMemory,
Detach: *flDetach,
Env: flEnv,
Cmd: runCmd,
Image: image,
}
return config, nil
}
type NetworkSettings struct {
IpAddress string
IpPrefixLen int
Gateway string
PortMapping map[string]string
}
func (container *Container) Cmd() *exec.Cmd {
return container.cmd
}
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
if err := json.Unmarshal(data, container); err != nil {
return err
}
return nil
}
func (container *Container) ToDisk() (err error) {
data, err := json.Marshal(container)
if err != nil {
return
}
return ioutil.WriteFile(container.jsonPath(), data, 0666)
}
func (container *Container) generateLXCConfig() error {
fo, err := os.Create(container.lxcConfigPath())
if err != nil {
return err
}
defer fo.Close()
if err := LxcTemplateCompiled.Execute(fo, container); err != nil {
return err
}
return nil
}
func (container *Container) startPty() error {
stdoutMaster, stdoutSlave, err := pty.Open()
if err != nil {
return err
}
container.cmd.Stdout = stdoutSlave
stderrMaster, stderrSlave, err := pty.Open()
if err != nil {
return err
}
container.cmd.Stderr = stderrSlave
// Copy the PTYs to our broadcasters
go func() {
defer container.stdout.Close()
io.Copy(container.stdout, stdoutMaster)
}()
go func() {
defer container.stderr.Close()
io.Copy(container.stderr, stderrMaster)
}()
// stdin
var stdinSlave io.ReadCloser
if container.Config.OpenStdin {
stdinMaster, stdinSlave, err := pty.Open()
if err != nil {
return err
}
container.cmd.Stdin = stdinSlave
// FIXME: The following appears to be broken.
// "cannot set terminal process group (-1): Inappropriate ioctl for device"
// container.cmd.SysProcAttr = &syscall.SysProcAttr{Setctty: true, Setsid: true}
go func() {
defer container.stdin.Close()
io.Copy(stdinMaster, container.stdin)
}()
}
if err := container.cmd.Start(); err != nil {
return err
}
stdoutSlave.Close()
stderrSlave.Close()
if stdinSlave != nil {
stdinSlave.Close()
}
return nil
}
func (container *Container) start() error {
container.cmd.Stdout = container.stdout
container.cmd.Stderr = container.stderr
if container.Config.OpenStdin {
stdin, err := container.cmd.StdinPipe()
if err != nil {
return err
}
go func() {
defer stdin.Close()
io.Copy(stdin, container.stdin)
}()
}
return container.cmd.Start()
}
func (container *Container) Start() error {
if err := container.EnsureMounted(); err != nil {
return err
}
if err := container.allocateNetwork(); err != nil {
return err
}
if err := container.generateLXCConfig(); err != nil {
return err
}
params := []string{
"-n", container.Id,
"-f", container.lxcConfigPath(),
"--",
"/sbin/init",
}
// Networking
params = append(params, "-g", container.network.Gateway.String())
// User
if container.Config.User != "" {
params = append(params, "-u", container.Config.User)
}
// Program
params = append(params, "--", container.Path)
params = append(params, container.Args...)
container.cmd = exec.Command("/usr/bin/lxc-start", params...)
// Setup environment
container.cmd.Env = append(
[]string{
"HOME=/",
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
},
container.Config.Env...,
)
var err error
if container.Config.Tty {
container.cmd.Env = append(
[]string{"TERM=xterm"},
container.cmd.Env...,
)
err = container.startPty()
} else {
err = container.start()
}
if err != nil {
return err
}
// FIXME: save state on disk *first*, then converge
// this way disk state is used as a journal, eg. we can restore after crash etc.
container.State.setRunning(container.cmd.Process.Pid)
container.ToDisk()
go container.monitor()
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
}
// StdinPipe() returns a pipe connected to the standard input of the container's
// active process.
//
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 newBufReader(reader), nil
}
func (container *Container) StderrPipe() (io.ReadCloser, error) {
reader, writer := io.Pipe()
container.stderr.AddWriter(writer)
return newBufReader(reader), nil
}
func (container *Container) allocateNetwork() error {
iface, err := container.runtime.networkManager.Allocate()
if err != nil {
return err
}
container.NetworkSettings.PortMapping = make(map[string]string)
for _, port := range container.Config.Ports {
if extPort, err := iface.AllocatePort(port); err != nil {
iface.Release()
return err
} else {
container.NetworkSettings.PortMapping[strconv.Itoa(port)] = strconv.Itoa(extPort)
}
}
container.network = iface
container.NetworkSettings.IpAddress = iface.IPNet.IP.String()
container.NetworkSettings.IpPrefixLen, _ = iface.IPNet.Mask.Size()
container.NetworkSettings.Gateway = iface.Gateway.String()
return nil
}
func (container *Container) releaseNetwork() error {
err := container.network.Release()
container.network = nil
container.NetworkSettings = &NetworkSettings{}
return err
}
func (container *Container) monitor() {
// Wait for the program to exit
container.cmd.Wait()
exitCode := container.cmd.ProcessState.Sys().(syscall.WaitStatus).ExitStatus()
// Cleanup
if err := container.releaseNetwork(); err != nil {
log.Printf("%v: Failed to release network: %v", container.Id, err)
}
container.stdout.Close()
container.stderr.Close()
if err := container.Unmount(); err != nil {
log.Printf("%v: Failed to umount filesystem: %v", container.Id, err)
}
// Re-create a brand new stdin pipe once the container exited
if container.Config.OpenStdin {
container.stdin, container.stdinPipe = io.Pipe()
}
// Report status back
container.State.setStopped(exitCode)
container.ToDisk()
}
func (container *Container) kill() error {
if container.cmd == nil {
return nil
}
if err := container.cmd.Process.Kill(); err != nil {
return err
}
// Wait for the container to be actually stopped
container.Wait()
return nil
}
func (container *Container) Kill() error {
if !container.State.Running {
return nil
}
return container.kill()
}
func (container *Container) Stop() error {
if !container.State.Running {
return nil
}
// 1. Send a SIGTERM
if output, err := exec.Command("/usr/bin/lxc-kill", "-n", container.Id, "15").CombinedOutput(); err != nil {
log.Printf(string(output))
log.Printf("Failed to send SIGTERM to the process, force killing")
if err := container.Kill(); err != nil {
return err
}
}
// 2. Wait for the process to exit on its own
if err := container.WaitTimeout(10 * time.Second); err != nil {
log.Printf("Container %v failed to exit within 10 seconds of SIGTERM - using the force", container.Id)
if err := container.Kill(); err != nil {
return err
}
}
return nil
}
func (container *Container) Restart() error {
if err := container.Stop(); err != nil {
return err
}
if err := container.Start(); err != nil {
return err
}
return nil
}
// Wait blocks until the container stops running, then returns its exit code.
func (container *Container) Wait() int {
for container.State.Running {
container.State.wait()
}
return container.State.ExitCode
}
func (container *Container) ExportRw() (Archive, error) {
return Tar(container.rwPath(), Uncompressed)
}
func (container *Container) Export() (Archive, error) {
if err := container.EnsureMounted(); err != nil {
return nil, err
}
return Tar(container.RootfsPath(), Uncompressed)
}
func (container *Container) WaitTimeout(timeout time.Duration) error {
done := make(chan bool)
go func() {
container.Wait()
done <- true
}()
select {
case <-time.After(timeout):
return errors.New("Timed Out")
case <-done:
return nil
}
return nil
}
func (container *Container) EnsureMounted() error {
if mounted, err := container.Mounted(); err != nil {
return err
} else if mounted {
return nil
}
return container.Mount()
}
func (container *Container) Mount() error {
image, err := container.GetImage()
if err != nil {
return err
}
return image.Mount(container.RootfsPath(), container.rwPath())
}
func (container *Container) Changes() ([]Change, error) {
image, err := container.GetImage()
if err != nil {
return nil, err
}
return image.Changes(container.rwPath())
}
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) Mounted() (bool, error) {
return Mounted(container.RootfsPath())
}
func (container *Container) Unmount() error {
return Unmount(container.RootfsPath())
}
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) jsonPath() string {
return path.Join(container.root, "config.json")
}
func (container *Container) lxcConfigPath() string {
return path.Join(container.root, "config.lxc")
}
// This method must be exported to be used from the lxc template
func (container *Container) RootfsPath() string {
return path.Join(container.root, "rootfs")
}
func (container *Container) rwPath() string {
return path.Join(container.root, "rw")
}
func validateId(id string) error {
if id == "" {
return fmt.Errorf("Invalid empty id")
}
return nil
}