Golang system.Execv函数代码示例

// 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 (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, consolePath string, syncPipe *SyncPipe, args []string) error {
	rootfs, err := utils.ResolveRootfs(uncleanRootfs)
	if err != nil {
		return err
	}

	// We always read this as it is a way to sync with the parent as well
	ns.logger.Printf("reading from sync pipe fd %d\n", syncPipe.child.Fd())
	context, err := syncPipe.ReadFromParent()
	if err != nil {
		syncPipe.Close()
		return err
	}
	ns.logger.Println("received context from parent")
	syncPipe.Close()

	if consolePath != "" {
		ns.logger.Printf("setting up %s as console\n", 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, context); err != nil {
		return fmt.Errorf("setup networking %s", err)
	}

	label.Init()
	ns.logger.Println("setup mount namespace")
	if err := mount.InitializeMountNamespace(rootfs, consolePath, container); err != nil {
		return fmt.Errorf("setup mount namespace %s", err)
	}
	if err := system.Sethostname(container.Hostname); err != nil {
		return fmt.Errorf("sethostname %s", err)
	}
	if err := finalizeNamespace(container); err != nil {
		return fmt.Errorf("finalize namespace %s", err)
	}

	if profile := container.Context["apparmor_profile"]; profile != "" {
		ns.logger.Printf("setting apparmor profile %s\n", profile)
		if err := apparmor.ApplyProfile(os.Getpid(), profile); err != nil {
			return err
		}
	}
	runtime.LockOSThread()
	if err := label.SetProcessLabel(container.Context["process_label"]); err != nil {
		return fmt.Errorf("SetProcessLabel label %s", err)
	}
	ns.logger.Printf("execing %s\n", args[0])
	return system.Execv(args[0], args[0:], container.Env)
}

// 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 (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, console string, syncPipe *SyncPipe, args []string) error {
	rootfs, err := utils.ResolveRootfs(uncleanRootfs)
	if err != nil {
		return err
	}

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

	if console != "" {
		slave, err := system.OpenTerminal(console, syscall.O_RDWR)
		if err != nil {
			return fmt.Errorf("open terminal %s", err)
		}
		if err := dupSlave(slave); err != nil {
			return fmt.Errorf("dup2 slave %s", err)
		}
	}
	if _, err := system.Setsid(); err != nil {
		return fmt.Errorf("setsid %s", err)
	}
	if console != "" {
		if err := system.Setctty(); err != nil {
			return fmt.Errorf("setctty %s", err)
		}
	}
	// this is our best effort to let the process know that the parent has died and that it
	// should it should act on it how it sees fit
	if err := system.ParentDeathSignal(uintptr(syscall.SIGTERM)); err != nil {
		return fmt.Errorf("parent death signal %s", err)
	}
	if err := setupNewMountNamespace(rootfs, container.Mounts, console, container.ReadonlyFs, container.NoPivotRoot); err != nil {
		return fmt.Errorf("setup mount namespace %s", err)
	}
	if err := setupNetwork(container, context); err != nil {
		return fmt.Errorf("setup networking %s", err)
	}
	if err := system.Sethostname(container.Hostname); err != nil {
		return fmt.Errorf("sethostname %s", err)
	}
	if err := finalizeNamespace(container); err != nil {
		return fmt.Errorf("finalize namespace %s", err)
	}

	if err := apparmor.ApplyProfile(os.Getpid(), container.Context["apparmor_profile"]); err != nil {
		return err
	}
	return system.Execv(args[0], args[0:], container.Env)
}

// 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 (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, console string, syncPipe *SyncPipe, args []string) error {
	rootfs, err := utils.ResolveRootfs(uncleanRootfs)
	if err != nil {
		return err
	}

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

	if console != "" {
		// close pipes so that we can replace it with the pty
		closeStdPipes()
		slave, err := system.OpenTerminal(console, syscall.O_RDWR)
		if err != nil {
			return fmt.Errorf("open terminal %s", err)
		}
		if err := dupSlave(slave); err != nil {
			return fmt.Errorf("dup2 slave %s", err)
		}
	}
	if _, err := system.Setsid(); err != nil {
		return fmt.Errorf("setsid %s", err)
	}
	if console != "" {
		if err := system.Setctty(); err != nil {
			return fmt.Errorf("setctty %s", err)
		}
	}

	/*
		if err := system.ParentDeathSignal(); err != nil {
			return fmt.Errorf("parent death signal %s", err)
		}
	*/
	if err := setupNewMountNamespace(rootfs, console, container.ReadonlyFs); err != nil {
		return fmt.Errorf("setup mount namespace %s", err)
	}
	if err := setupNetwork(container, context); err != nil {
		return fmt.Errorf("setup networking %s", err)
	}
	if err := system.Sethostname(container.Hostname); err != nil {
		return fmt.Errorf("sethostname %s", err)
	}
	if err := finalizeNamespace(container); err != nil {
		return fmt.Errorf("finalize namespace %s", err)
	}
	return system.Execv(args[0], args[0:], container.Env)
}

// ExecIn uses an existing pid and joins the pid's namespaces with the new command.
func ExecIn(container *libcontainer.Config, state *libcontainer.State, args []string) error {
	// TODO(vmarmol): If this gets too long, send it over a pipe to the child.
	// Marshall the container into JSON since it won't be available in the namespace.
	containerJson, err := json.Marshal(container)
	if err != nil {
		return err
	}

	// Enter the namespace and then finish setup
	finalArgs := []string{os.Args[0], "nsenter", "--nspid", strconv.Itoa(state.InitPid), "--containerjson", string(containerJson), "--"}
	finalArgs = append(finalArgs, args...)
	if err := system.Execv(finalArgs[0], finalArgs[0:], os.Environ()); err != nil {
		return err
	}
	panic("unreachable")
}

// NsEnter is run after entering the namespace.
func NsEnter(container *libcontainer.Container, processLabel string, nspid int, args []string) error {
	// clear the current processes env and replace it with the environment
	// defined on the container
	if err := LoadContainerEnvironment(container); err != nil {
		return err
	}
	if err := FinalizeNamespace(container); err != nil {
		return err
	}
	if err := label.SetProcessLabel(processLabel); err != nil {
		return err
	}
	if err := system.Execv(args[0], args[0:], container.Env); err != nil {
		return err
	}
	panic("unreachable")
}

// ExecIn uses an existing pid and joins the pid's namespaces with the new command.
func ExecIn(container *libcontainer.Container, nspid int, args []string) error {
	// TODO(vmarmol): If this gets too long, send it over a pipe to the child.
	// Marshall the container into JSON since it won't be available in the namespace.
	containerJson, err := json.Marshal(container)
	if err != nil {
		return err
	}

	// TODO(vmarmol): Move this to the container JSON.
	processLabel, err := label.GetPidCon(nspid)
	if err != nil {
		return err
	}

	// Enter the namespace and then finish setup
	finalArgs := []string{os.Args[0], "nsenter", strconv.Itoa(nspid), processLabel, string(containerJson)}
	finalArgs = append(finalArgs, args...)
	if err := system.Execv(finalArgs[0], finalArgs[0:], os.Environ()); err != nil {
		return err
	}
	panic("unreachable")
}

// 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 (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, console string, syncPipe *SyncPipe, args []string) error {
	rootfs, err := utils.ResolveRootfs(uncleanRootfs)
	if err != nil {
		return err
	}

	// We always read this as it is a way to sync with the parent as well
	ns.logger.Printf("reading from sync pipe fd %d\n", syncPipe.child.Fd())
	context, err := syncPipe.ReadFromParent()
	if err != nil {
		syncPipe.Close()
		return err
	}
	ns.logger.Println("received context from parent")
	syncPipe.Close()

	if console != "" {
		ns.logger.Printf("setting up %s as console\n", console)
		slave, err := system.OpenTerminal(console, syscall.O_RDWR)
		if err != nil {
			return fmt.Errorf("open terminal %s", err)
		}
		if err := dupSlave(slave); err != nil {
			return fmt.Errorf("dup2 slave %s", err)
		}
	}
	if _, err := system.Setsid(); err != nil {
		return fmt.Errorf("setsid %s", err)
	}
	if console != "" {
		if err := system.Setctty(); err != nil {
			return fmt.Errorf("setctty %s", err)
		}
	}
	// this is our best effort to let the process know that the parent has died and that it
	// should it should act on it how it sees fit
	if err := system.ParentDeathSignal(uintptr(syscall.SIGTERM)); err != nil {
		return fmt.Errorf("parent death signal %s", err)
	}
	ns.logger.Println("setup mount namespace")
	if err := setupNewMountNamespace(rootfs, container.Mounts, console, container.ReadonlyFs, container.NoPivotRoot, container.Context["mount_label"]); err != nil {
		return fmt.Errorf("setup mount namespace %s", err)
	}
	if err := setupNetwork(container, context); err != nil {
		return fmt.Errorf("setup networking %s", err)
	}
	if err := system.Sethostname(container.Hostname); err != nil {
		return fmt.Errorf("sethostname %s", err)
	}
	if err := finalizeNamespace(container); err != nil {
		return fmt.Errorf("finalize namespace %s", err)
	}

	if profile := container.Context["apparmor_profile"]; profile != "" {
		ns.logger.Printf("setting apparmor profile %s\n", profile)
		if err := apparmor.ApplyProfile(os.Getpid(), profile); err != nil {
			return err
		}
	}
	runtime.LockOSThread()
	if err := label.SetProcessLabel(container.Context["process_label"]); err != nil {
		return fmt.Errorf("SetProcessLabel label %s", err)
	}
	ns.logger.Printf("execing %s\n", args[0])
	return system.Execv(args[0], args[0:], container.Env)
}

// 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.Container, uncleanRootfs, consolePath string, syncPipe *SyncPipe, args []string) error {
	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
	context, err := syncPipe.ReadFromParent()
	if err != nil {
		syncPipe.Close()
		return err
	}
	syncPipe.Close()

	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, context); err != nil {
		return fmt.Errorf("setup networking %s", err)
	}

	label.Init()

	if err := mount.InitializeMountNamespace(rootfs, consolePath, container); 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.Context["apparmor_profile"]); err != nil {
		return fmt.Errorf("set apparmor profile %s: %s", container.Context["apparmor_profile"], err)
	}
	if err := label.SetProcessLabel(container.Context["process_label"]); err != nil {
		return fmt.Errorf("set process label %s", err)
	}
	if container.Context["restrictions"] != "" {
		if err := restrict.Restrict("proc", "sys"); err != nil {
			return err
		}
	}
	if err := FinalizeNamespace(container); err != nil {
		return fmt.Errorf("finalize namespace %s", err)
	}
	return system.Execv(args[0], args[0:], container.Env)
}

// 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)
}

// ExecIn uses an existing pid and joins the pid's namespaces with the new command.
func ExecIn(container *libcontainer.Container, nspid int, args []string) (int, error) {
	// clear the current processes env and replace it with the environment
	// defined on the container
	if err := LoadContainerEnvironment(container); err != nil {
		return -1, err
	}

	for key, enabled := range container.Namespaces {
		// skip the PID namespace on unshare because it it not supported
		if enabled && key != "NEWPID" {
			if ns := libcontainer.GetNamespace(key); ns != nil {
				if err := system.Unshare(ns.Value); err != nil {
					return -1, err
				}
			}
		}
	}
	fds, err := getNsFds(nspid, container)
	closeFds := func() {
		for _, f := range fds {
			system.Closefd(f)
		}
	}
	if err != nil {
		closeFds()
		return -1, err
	}
	processLabel, err := label.GetPidCon(nspid)
	if err != nil {
		closeFds()
		return -1, err
	}
	// foreach namespace fd, use setns to join an existing container's namespaces
	for _, fd := range fds {
		if fd > 0 {
			if err := system.Setns(fd, 0); err != nil {
				closeFds()
				return -1, fmt.Errorf("setns %s", err)
			}
		}
		system.Closefd(fd)
	}

	// if the container has a new pid and mount namespace we need to
	// remount proc and sys to pick up the changes
	if container.Namespaces["NEWNS"] && container.Namespaces["NEWPID"] {
		pid, err := system.Fork()
		if err != nil {
			return -1, err
		}
		if pid == 0 {
			// TODO: make all raw syscalls to be fork safe
			if err := system.Unshare(syscall.CLONE_NEWNS); err != nil {
				return -1, err
			}
			if err := mount.RemountProc(); err != nil {
				return -1, fmt.Errorf("remount proc %s", err)
			}
			if err := mount.RemountSys(); err != nil {
				return -1, fmt.Errorf("remount sys %s", err)
			}
			goto dropAndExec
		}
		proc, err := os.FindProcess(pid)
		if err != nil {
			return -1, err
		}
		state, err := proc.Wait()
		if err != nil {
			return -1, err
		}
		os.Exit(state.Sys().(syscall.WaitStatus).ExitStatus())
	}
dropAndExec:
	if err := FinalizeNamespace(container); err != nil {
		return -1, err
	}
	err = label.SetProcessLabel(processLabel)
	if err != nil {
		return -1, err
	}
	if err := system.Execv(args[0], args[0:], container.Env); err != nil {
		return -1, err
	}
	panic("unreachable")
}

// ExecIn uses an existing pid and joins the pid's namespaces with the new command.
func (ns *linuxNs) ExecIn(container *libcontainer.Container, nspid int, args []string) (int, error) {
	for _, ns := range container.Namespaces {
		if err := system.Unshare(ns.Value); err != nil {
			return -1, err
		}
	}
	fds, err := ns.getNsFds(nspid, container)
	closeFds := func() {
		for _, f := range fds {
			system.Closefd(f)
		}
	}
	if err != nil {
		closeFds()
		return -1, err
	}

	// foreach namespace fd, use setns to join an existing container's namespaces
	for _, fd := range fds {
		if fd > 0 {
			if err := system.Setns(fd, 0); err != nil {
				closeFds()
				return -1, fmt.Errorf("setns %s", err)
			}
		}
		system.Closefd(fd)
	}

	// if the container has a new pid and mount namespace we need to
	// remount proc and sys to pick up the changes
	if container.Namespaces.Contains("NEWNS") && container.Namespaces.Contains("NEWPID") {
		pid, err := system.Fork()
		if err != nil {
			return -1, err
		}
		if pid == 0 {
			// TODO: make all raw syscalls to be fork safe
			if err := system.Unshare(syscall.CLONE_NEWNS); err != nil {
				return -1, err
			}
			if err := remountProc(); err != nil {
				return -1, fmt.Errorf("remount proc %s", err)
			}
			if err := remountSys(); err != nil {
				return -1, fmt.Errorf("remount sys %s", err)
			}
			goto dropAndExec
		}
		proc, err := os.FindProcess(pid)
		if err != nil {
			return -1, err
		}
		state, err := proc.Wait()
		if err != nil {
			return -1, err
		}
		os.Exit(state.Sys().(syscall.WaitStatus).ExitStatus())
	}
dropAndExec:
	if err := finalizeNamespace(container); err != nil {
		return -1, err
	}
	if err := system.Execv(args[0], args[0:], container.Env); err != nil {
		return -1, err
	}
	panic("unreachable")
}