runc/nsinit/exec.go

123 lines
2.8 KiB
Go

package main
import (
"os"
"os/signal"
"syscall"
"github.com/codegangsta/cli"
"github.com/docker/libcontainer"
"github.com/docker/libcontainer/utils"
)
var standardEnvironment = &cli.StringSlice{
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"HOSTNAME=nsinit",
"TERM=xterm",
}
var execCommand = cli.Command{
Name: "exec",
Usage: "execute a new command inside a container",
Action: execAction,
Flags: append([]cli.Flag{
cli.BoolFlag{Name: "tty,t", Usage: "allocate a TTY to the container"},
cli.StringFlag{Name: "id", Value: "nsinit", Usage: "specify the ID for a container"},
cli.StringFlag{Name: "config", Value: "container.json", Usage: "path to the configuration file"},
cli.BoolFlag{Name: "create", Usage: "create the container's configuration on the fly with arguments"},
cli.StringFlag{Name: "user,u", Value: "root", Usage: "set the user, uid, and/or gid for the process"},
cli.StringFlag{Name: "cwd", Value: "", Usage: "set the current working dir"},
cli.StringSliceFlag{Name: "env", Value: standardEnvironment, Usage: "set environment variables for the process"},
}, createFlags...),
}
func execAction(context *cli.Context) {
factory, err := loadFactory(context)
if err != nil {
fatal(err)
}
config, err := loadConfig(context)
if err != nil {
fatal(err)
}
rootuid, err := config.HostUID()
if err != nil {
fatal(err)
}
tty, err := newTty(context, rootuid)
if err != nil {
fatal(err)
}
created := false
container, err := factory.Load(context.String("id"))
if err != nil {
if tty.console != nil {
config.Console = tty.console.Path()
}
created = true
if container, err = factory.Create(context.String("id"), config); err != nil {
tty.Close()
fatal(err)
}
}
go handleSignals(container, tty)
process := &libcontainer.Process{
Args: context.Args(),
Env: context.StringSlice("env"),
User: context.String("user"),
Cwd: context.String("cwd"),
Stdin: os.Stdin,
Stdout: os.Stdout,
Stderr: os.Stderr,
}
if err := tty.attach(process); err != nil {
fatal(err)
}
pid, err := container.Start(process)
if err != nil {
tty.Close()
if created {
container.Destroy()
}
fatal(err)
}
proc, err := os.FindProcess(pid)
if err != nil {
tty.Close()
if created {
container.Destroy()
}
fatal(err)
}
status, err := proc.Wait()
if err != nil {
tty.Close()
if created {
container.Destroy()
}
fatal(err)
}
if created {
if err := container.Destroy(); err != nil {
tty.Close()
fatal(err)
}
}
tty.Close()
os.Exit(utils.ExitStatus(status.Sys().(syscall.WaitStatus)))
}
func handleSignals(container libcontainer.Container, tty *tty) {
sigc := make(chan os.Signal, 10)
signal.Notify(sigc)
tty.resize()
for sig := range sigc {
switch sig {
case syscall.SIGWINCH:
tty.resize()
default:
container.Signal(sig)
}
}
}