3fde553297
This temp. expands the Exec method's signature but adds a more robust way to know when the container's process is actually released and begins to run. The network interfaces are not guaranteed to be up yet but this provides a more accurate view with a single callback at this time. Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
113 lines
2.7 KiB
Go
113 lines
2.7 KiB
Go
package main
|
|
|
|
import (
|
|
"encoding/json"
|
|
"flag"
|
|
"io/ioutil"
|
|
"log"
|
|
"os"
|
|
"path/filepath"
|
|
"strconv"
|
|
|
|
"github.com/dotcloud/docker/pkg/libcontainer"
|
|
"github.com/dotcloud/docker/pkg/libcontainer/nsinit"
|
|
)
|
|
|
|
var (
|
|
root, console, logs string
|
|
pipeFd int
|
|
)
|
|
|
|
func registerFlags() {
|
|
flag.StringVar(&console, "console", "", "console (pty slave) path")
|
|
flag.IntVar(&pipeFd, "pipe", 0, "sync pipe fd")
|
|
flag.StringVar(&root, "root", ".", "root for storing configuration data")
|
|
flag.StringVar(&logs, "log", "none", "set stderr or a filepath to enable logging")
|
|
|
|
flag.Parse()
|
|
}
|
|
|
|
func main() {
|
|
registerFlags()
|
|
|
|
if flag.NArg() < 1 {
|
|
log.Fatalf("wrong number of arguments %d", flag.NArg())
|
|
}
|
|
container, err := loadContainer()
|
|
if err != nil {
|
|
log.Fatalf("Unable to load container: %s", err)
|
|
}
|
|
|
|
ns, err := newNsInit()
|
|
if err != nil {
|
|
log.Fatalf("Unable to initialize nsinit: %s", err)
|
|
}
|
|
|
|
switch flag.Arg(0) {
|
|
case "exec": // this is executed outside of the namespace in the cwd
|
|
var exitCode int
|
|
nspid, err := readPid()
|
|
if err != nil {
|
|
if !os.IsNotExist(err) {
|
|
log.Fatalf("Unable to read pid: %s", err)
|
|
}
|
|
}
|
|
if nspid > 0 {
|
|
exitCode, err = ns.ExecIn(container, nspid, flag.Args()[1:])
|
|
} else {
|
|
term := nsinit.NewTerminal(os.Stdin, os.Stdout, os.Stderr, container.Tty)
|
|
exitCode, err = ns.Exec(container, term, root, flag.Args()[1:], nil)
|
|
}
|
|
if err != nil {
|
|
log.Fatalf("Failed to exec: %s", err)
|
|
}
|
|
os.Exit(exitCode)
|
|
case "init": // this is executed inside of the namespace to setup the container
|
|
cwd, err := os.Getwd()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
if flag.NArg() < 2 {
|
|
log.Fatalf("wrong number of arguments %d", flag.NArg())
|
|
}
|
|
syncPipe, err := nsinit.NewSyncPipeFromFd(0, uintptr(pipeFd))
|
|
if err != nil {
|
|
log.Fatalf("Unable to create sync pipe: %s", err)
|
|
}
|
|
if err := ns.Init(container, cwd, console, syncPipe, flag.Args()[1:]); err != nil {
|
|
log.Fatalf("Unable to initialize for container: %s", err)
|
|
}
|
|
default:
|
|
log.Fatalf("command not supported for nsinit %s", flag.Arg(0))
|
|
}
|
|
}
|
|
|
|
func loadContainer() (*libcontainer.Container, error) {
|
|
f, err := os.Open(filepath.Join(root, "container.json"))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
defer f.Close()
|
|
|
|
var container *libcontainer.Container
|
|
if err := json.NewDecoder(f).Decode(&container); err != nil {
|
|
return nil, err
|
|
}
|
|
return container, nil
|
|
}
|
|
|
|
func readPid() (int, error) {
|
|
data, err := ioutil.ReadFile(filepath.Join(root, "pid"))
|
|
if err != nil {
|
|
return -1, err
|
|
}
|
|
pid, err := strconv.Atoi(string(data))
|
|
if err != nil {
|
|
return -1, err
|
|
}
|
|
return pid, nil
|
|
}
|
|
|
|
func newNsInit() (nsinit.NsInit, error) {
|
|
return nsinit.NewNsInit(&nsinit.DefaultCommandFactory{root}), nil
|
|
}
|