traefik/integration/vendor/github.com/opencontainers/runc/start.go

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2017-02-07 21:33:23 +00:00
// +build linux
package main
import (
"fmt"
"os"
"runtime"
"strconv"
"github.com/Sirupsen/logrus"
"github.com/codegangsta/cli"
"github.com/opencontainers/runc/libcontainer"
"github.com/opencontainers/specs"
)
const SD_LISTEN_FDS_START = 3
// default action is to start a container
var startCommand = cli.Command{
Name: "start",
Usage: "create and run a container",
Flags: []cli.Flag{
cli.StringFlag{
Name: "bundle, b",
Value: "",
Usage: "path to the root of the bundle directory",
},
},
Action: func(context *cli.Context) {
bundle := context.String("bundle")
if bundle != "" {
if err := os.Chdir(bundle); err != nil {
fatal(err)
}
}
spec, rspec, err := loadSpec(specConfig, runtimeConfig)
if err != nil {
fatal(err)
}
notifySocket := os.Getenv("NOTIFY_SOCKET")
if notifySocket != "" {
setupSdNotify(spec, rspec, notifySocket)
}
listenFds := os.Getenv("LISTEN_FDS")
listenPid := os.Getenv("LISTEN_PID")
if listenFds != "" && listenPid == strconv.Itoa(os.Getpid()) {
setupSocketActivation(spec, listenFds)
}
if os.Geteuid() != 0 {
logrus.Fatal("runc should be run as root")
}
status, err := startContainer(context, spec, rspec)
if err != nil {
logrus.Fatalf("Container start failed: %v", err)
}
// exit with the container's exit status so any external supervisor is
// notified of the exit with the correct exit status.
os.Exit(status)
},
}
func init() {
if len(os.Args) > 1 && os.Args[1] == "init" {
runtime.GOMAXPROCS(1)
runtime.LockOSThread()
factory, _ := libcontainer.New("")
if err := factory.StartInitialization(); err != nil {
fatal(err)
}
panic("--this line should have never been executed, congratulations--")
}
}
func startContainer(context *cli.Context, spec *specs.LinuxSpec, rspec *specs.LinuxRuntimeSpec) (int, error) {
config, err := createLibcontainerConfig(context.GlobalString("id"), spec, rspec)
if err != nil {
return -1, err
}
if _, err := os.Stat(config.Rootfs); err != nil {
if os.IsNotExist(err) {
return -1, fmt.Errorf("Rootfs (%q) does not exist", config.Rootfs)
}
return -1, err
}
rootuid, err := config.HostUID()
if err != nil {
return -1, err
}
factory, err := loadFactory(context)
if err != nil {
return -1, err
}
container, err := factory.Create(context.GlobalString("id"), config)
if err != nil {
return -1, err
}
// ensure that the container is always removed if we were the process
// that created it.
defer destroy(container)
process := newProcess(spec.Process)
// Support on-demand socket activation by passing file descriptors into the container init process.
if os.Getenv("LISTEN_FDS") != "" {
listenFdsInt, err := strconv.Atoi(os.Getenv("LISTEN_FDS"))
if err != nil {
return -1, err
}
for i := SD_LISTEN_FDS_START; i < (listenFdsInt + SD_LISTEN_FDS_START); i++ {
process.ExtraFiles = append(process.ExtraFiles, os.NewFile(uintptr(i), ""))
}
}
tty, err := newTty(spec.Process.Terminal, process, rootuid)
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)
}
// If systemd is supporting sd_notify protocol, this function will add support
// for sd_notify protocol from within the container.
func setupSdNotify(spec *specs.LinuxSpec, rspec *specs.LinuxRuntimeSpec, notifySocket string) {
mountName := "sdNotify"
spec.Mounts = append(spec.Mounts, specs.MountPoint{Name: mountName, Path: notifySocket})
spec.Process.Env = append(spec.Process.Env, fmt.Sprintf("NOTIFY_SOCKET=%s", notifySocket))
rspec.Mounts[mountName] = specs.Mount{Type: "bind", Source: notifySocket, Options: []string{"bind"}}
}
// If systemd is supporting on-demand socket activation, this function will add support
// for on-demand socket activation for the containerized service.
func setupSocketActivation(spec *specs.LinuxSpec, listenFds string) {
spec.Process.Env = append(spec.Process.Env, fmt.Sprintf("LISTEN_FDS=%s", listenFds), "LISTEN_PID=1")
}
func destroy(container libcontainer.Container) {
status, err := container.Status()
if err != nil {
logrus.Error(err)
}
if status != libcontainer.Checkpointed {
if err := container.Destroy(); err != nil {
logrus.Error(err)
}
}
}