runc/exec.go

125 lines
2.5 KiB
Go

// +build linux
package main
import (
"fmt"
"os"
"path"
"strconv"
"strings"
"github.com/Sirupsen/logrus"
"github.com/codegangsta/cli"
)
var execCommand = cli.Command{
Name: "exec",
Usage: "execute new process inside the container",
Flags: []cli.Flag{
cli.StringFlag{
Name: "console",
Usage: "specify the pty slave path for use with the container",
},
cli.StringFlag{
Name: "cwd",
Usage: "current working directory in the container",
},
cli.StringSliceFlag{
Name: "env, e",
Usage: "set environment variables",
},
cli.BoolFlag{
Name: "tty, t",
Usage: "allocate a pseudo-TTY",
},
cli.StringFlag{
Name: "user, u",
Usage: "UID (format: <uid>[:<gid>])",
},
},
Action: func(context *cli.Context) {
if len(context.Args()) == 0 {
logrus.Fatal("pass the command")
}
if os.Geteuid() != 0 {
logrus.Fatal("runc should be run as root")
}
status, err := execProcess(context, context.Args())
if err != nil {
logrus.Fatalf("exec failed: %v", err)
}
os.Exit(status)
},
}
func execProcess(context *cli.Context, args []string) (int, error) {
container, err := getContainer(context)
if err != nil {
return -1, err
}
bundle := container.Config().Rootfs
if err := os.Chdir(path.Dir(bundle)); err != nil {
return -1, err
}
spec, _, err := loadSpec(specConfig, runtimeConfig)
if err != nil {
return -1, err
}
p := spec.Process
// override the cwd, if passed
if context.String("cwd") != "" {
p.Cwd = context.String("cwd")
}
// append the passed env variables
for _, e := range context.StringSlice("env") {
p.Env = append(p.Env, e)
}
// set the tty
if context.IsSet("tty") {
p.Terminal = context.Bool("tty")
}
// override the user, if passed
if context.String("user") != "" {
u := strings.SplitN(context.String("user"), ":", 2)
if len(u) > 1 {
gid, err := strconv.Atoi(u[1])
if err != nil {
return -1, fmt.Errorf("parsing %s as int for gid failed: %v", u[1], err)
}
p.User.GID = uint32(gid)
}
uid, err := strconv.Atoi(u[0])
if err != nil {
return -1, fmt.Errorf("parsing %s as int for uid failed: %v", u[0], err)
}
p.User.UID = uint32(uid)
}
process := newProcess(p)
process.Args = args
rootuid, err := container.Config().HostUID()
if err != nil {
return -1, err
}
tty, err := newTty(p.Terminal, process, rootuid, context.String("console"))
if err != nil {
return -1, err
}
handler := newSignalHandler(tty)
defer handler.Close()
if err := container.Start(process); err != nil {
return -1, err
}
return handler.forward(process)
}