125 lines
2.8 KiB
Go
125 lines
2.8 KiB
Go
package main
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import (
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"os"
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"os/exec"
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"os/signal"
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"syscall"
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"github.com/codegangsta/cli"
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"github.com/docker/libcontainer"
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"github.com/docker/libcontainer/utils"
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)
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var standardEnvironment = &cli.StringSlice{
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"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
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"HOSTNAME=nsinit",
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"TERM=xterm",
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}
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var execCommand = cli.Command{
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Name: "exec",
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Usage: "execute a new command inside a container",
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Action: execAction,
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Flags: append([]cli.Flag{
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cli.BoolFlag{Name: "tty,t", Usage: "allocate a TTY to the container"},
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cli.BoolFlag{Name: "systemd", Usage: "Use systemd for managing cgroups, if available"},
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cli.StringFlag{Name: "id", Value: "nsinit", Usage: "specify the ID for a container"},
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cli.StringFlag{Name: "config", Value: "", Usage: "path to the configuration file"},
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cli.StringFlag{Name: "user,u", Value: "root", Usage: "set the user, uid, and/or gid for the process"},
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cli.StringFlag{Name: "cwd", Value: "", Usage: "set the current working dir"},
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cli.StringSliceFlag{Name: "env", Value: standardEnvironment, Usage: "set environment variables for the process"},
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}, createFlags...),
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}
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func execAction(context *cli.Context) {
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factory, err := loadFactory(context)
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if err != nil {
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fatal(err)
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}
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config, err := loadConfig(context)
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if err != nil {
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fatal(err)
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}
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created := false
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container, err := factory.Load(context.String("id"))
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if err != nil {
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created = true
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if container, err = factory.Create(context.String("id"), config); err != nil {
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fatal(err)
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}
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}
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process := &libcontainer.Process{
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Args: context.Args(),
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Env: context.StringSlice("env"),
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User: context.String("user"),
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Cwd: context.String("cwd"),
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Stdin: os.Stdin,
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Stdout: os.Stdout,
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Stderr: os.Stderr,
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}
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rootuid, err := config.HostUID()
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if err != nil {
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fatal(err)
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}
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tty, err := newTty(context, process, rootuid)
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if err != nil {
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fatal(err)
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}
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if err := tty.attach(process); err != nil {
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fatal(err)
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}
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go handleSignals(process, tty)
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err = container.Start(process)
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if err != nil {
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tty.Close()
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if created {
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container.Destroy()
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}
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fatal(err)
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}
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status, err := process.Wait()
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if err != nil {
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exitError, ok := err.(*exec.ExitError)
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if ok {
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status = exitError.ProcessState
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} else {
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tty.Close()
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if created {
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container.Destroy()
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}
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fatal(err)
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}
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}
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if created {
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status, err := container.Status()
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if err != nil {
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tty.Close()
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fatal(err)
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}
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if status != libcontainer.Checkpointed {
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if err := container.Destroy(); err != nil {
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tty.Close()
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fatal(err)
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}
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}
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}
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tty.Close()
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os.Exit(utils.ExitStatus(status.Sys().(syscall.WaitStatus)))
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}
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func handleSignals(container *libcontainer.Process, tty *tty) {
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sigc := make(chan os.Signal, 10)
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signal.Notify(sigc)
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tty.resize()
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for sig := range sigc {
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switch sig {
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case syscall.SIGWINCH:
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tty.resize()
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default:
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container.Signal(sig)
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}
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}
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}
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