// InitializeNetworking creates the container's network stack outside of the namespace and moves
// interfaces into the container's net namespaces if necessary
func InitializeNetworking(container *libcontainer.Config, nspid int, pipe *syncpipe.SyncPipe, networkState *network.NetworkState) error {
	for _, config := range container.Networks {
		strategy, err := network.GetStrategy(config.Type)
		if err != nil {
			return err
		}
		if err := strategy.Create((*network.Network)(config), nspid, networkState); err != nil {
			return err
		}
	}
	return pipe.SendToChild(networkState)
}

// TODO(vishh): This is part of the libcontainer API and it does much more than just namespaces related work.
// Move this to libcontainer package.
// Init is the init process that first runs inside a new namespace to setup mounts, users, networking,
// and other options required for the new container.
func Init(container *libcontainer.Config, uncleanRootfs, consolePath string, syncPipe *syncpipe.SyncPipe, args []string) (err error) {
	defer func() {
		if err != nil {
			syncPipe.ReportChildError(err)
		}
	}()

	rootfs, err := utils.ResolveRootfs(uncleanRootfs)
	if err != nil {
		return err
	}

	// clear the current processes env and replace it with the environment
	// defined on the container
	if err := LoadContainerEnvironment(container); err != nil {
		return err
	}

	// We always read this as it is a way to sync with the parent as well
	networkState, err := syncPipe.ReadFromParent()
	if err != nil {
		return err
	}

	if consolePath != "" {
		if err := console.OpenAndDup(consolePath); err != nil {
			return err
		}
	}
	if _, err := system.Setsid(); err != nil {
		return fmt.Errorf("setsid %s", err)
	}
	if consolePath != "" {
		if err := system.Setctty(); err != nil {
			return fmt.Errorf("setctty %s", err)
		}
	}
	if err := setupNetwork(container, networkState); err != nil {
		return fmt.Errorf("setup networking %s", err)
	}
	if err := setupRoute(container); err != nil {
		return fmt.Errorf("setup route %s", err)
	}

	label.Init()

	if err := mount.InitializeMountNamespace(rootfs,
		consolePath,
		(*mount.MountConfig)(container.MountConfig)); err != nil {
		return fmt.Errorf("setup mount namespace %s", err)
	}

	if container.Hostname != "" {
		if err := system.Sethostname(container.Hostname); err != nil {
			return fmt.Errorf("sethostname %s", err)
		}
	}

	runtime.LockOSThread()

	if err := apparmor.ApplyProfile(container.AppArmorProfile); err != nil {
		return fmt.Errorf("set apparmor profile %s: %s", container.AppArmorProfile, err)
	}

	if err := label.SetProcessLabel(container.ProcessLabel); err != nil {
		return fmt.Errorf("set process label %s", err)
	}

	// TODO: (crosbymichael) make this configurable at the Config level
	if container.RestrictSys {
		if err := restrict.Restrict("proc/sys", "proc/sysrq-trigger", "proc/irq", "proc/bus", "sys"); err != nil {
			return err
		}
	}

	pdeathSignal, err := system.GetParentDeathSignal()
	if err != nil {
		return fmt.Errorf("get parent death signal %s", err)
	}

	if err := FinalizeNamespace(container); err != nil {
		return fmt.Errorf("finalize namespace %s", err)
	}

	// FinalizeNamespace can change user/group which clears the parent death
	// signal, so we restore it here.
	if err := RestoreParentDeathSignal(pdeathSignal); err != nil {
		return fmt.Errorf("restore parent death signal %s", err)
	}

	return system.Execv(args[0], args[0:], container.Env)
}