Golang environment.ParseFromList函數代碼示例

func (e *LinuxExecutor) Start() error {
	// Run as "nobody" user so we don't leak root privilege to the
	// spawned process.
	if err := e.runAs("nobody"); err == nil && e.user != nil {
		e.cmd.SetUID(e.user.Uid)
		e.cmd.SetGID(e.user.Gid)
	}

	if e.alloc == nil {
		return errors.New("ConfigureTaskDir() must be called before Start()")
	}

	// Parse the commands arguments and replace instances of Nomad environment
	// variables.
	envVars, err := environment.ParseFromList(e.Cmd.Env)
	if err != nil {
		return err
	}

	combined := strings.Join(e.Cmd.Args, " ")
	parsed, err := args.ParseAndReplace(combined, envVars.Map())
	if err != nil {
		return err
	}
	e.Cmd.Args = parsed

	return e.spawnDaemon()
}

func (e *UniversalExecutor) Start() error {
	// Parse the commands arguments and replace instances of Nomad environment
	// variables.
	envVars, err := environment.ParseFromList(e.cmd.Env)
	if err != nil {
		return err
	}

	parsedPath, err := args.ParseAndReplace(e.cmd.Path, envVars.Map())
	if err != nil {
		return err
	} else if len(parsedPath) != 1 {
		return fmt.Errorf("couldn't properly parse command path: %v", e.cmd.Path)
	}

	e.cmd.Path = parsedPath[0]
	combined := strings.Join(e.cmd.Args, " ")
	parsed, err := args.ParseAndReplace(combined, envVars.Map())
	if err != nil {
		return err
	}
	e.Cmd.Args = parsed

	// We don't want to call ourself. We want to call Start on our embedded Cmd
	return e.cmd.Start()
}

func (e *BasicExecutor) Start() error {
	// Parse the commands arguments and replace instances of Nomad environment
	// variables.
	envVars, err := environment.ParseFromList(e.cmd.Env)
	if err != nil {
		return err
	}

	e.cmd.Path = args.ReplaceEnv(e.cmd.Path, envVars.Map())
	combined := strings.Join(e.cmd.Args, " ")
	parsed, err := args.ParseAndReplace(combined, envVars.Map())
	if err != nil {
		return err
	}
	e.cmd.Args = parsed

	spawnState := filepath.Join(e.allocDir, fmt.Sprintf("%s_%s", e.taskName, "exit_status"))
	e.spawn = spawn.NewSpawner(spawnState)
	e.spawn.SetCommand(&e.cmd)
	e.spawn.SetLogs(&spawn.Logs{
		Stdout: filepath.Join(e.taskDir, allocdir.TaskLocal, fmt.Sprintf("%v.stdout", e.taskName)),
		Stderr: filepath.Join(e.taskDir, allocdir.TaskLocal, fmt.Sprintf("%v.stderr", e.taskName)),
		Stdin:  os.DevNull,
	})

	return e.spawn.Spawn(nil)
}

// ConfigureTaskDir creates the necessary directory structure for a proper
// chroot. cleanTaskDir should be called after.
func (e *LinuxExecutor) ConfigureTaskDir(taskName string, alloc *allocdir.AllocDir) error {
	e.taskName = taskName
	e.allocDir = alloc.AllocDir

	taskDir, ok := alloc.TaskDirs[taskName]
	if !ok {
		fmt.Errorf("Couldn't find task directory for task %v", taskName)
	}
	e.taskDir = taskDir

	if err := alloc.MountSharedDir(taskName); err != nil {
		return err
	}

	// Embed ourselves if this is a test. This needs to be done so the test
	// binary is inside the chroot.
	if isTest(&e.cmd) {
		bin := e.cmd.Args[0]
		alloc.Embed(taskName, map[string]string{bin: bin})
	}

	if err := alloc.Embed(taskName, chrootEnv); err != nil {
		return err
	}

	// Mount dev
	dev := filepath.Join(taskDir, "dev")
	if !e.pathExists(dev) {
		if err := os.Mkdir(dev, 0777); err != nil {
			return fmt.Errorf("Mkdir(%v) failed: %v", dev, err)
		}

		if err := syscall.Mount("", dev, "devtmpfs", syscall.MS_RDONLY, ""); err != nil {
			return fmt.Errorf("Couldn't mount /dev to %v: %v", dev, err)
		}
	}

	// Mount proc
	proc := filepath.Join(taskDir, "proc")
	if !e.pathExists(proc) {
		if err := os.Mkdir(proc, 0777); err != nil {
			return fmt.Errorf("Mkdir(%v) failed: %v", proc, err)
		}

		if err := syscall.Mount("", proc, "proc", syscall.MS_RDONLY, ""); err != nil {
			return fmt.Errorf("Couldn't mount /proc to %v: %v", proc, err)
		}
	}

	// Set the tasks AllocDir environment variable.
	env, err := environment.ParseFromList(e.cmd.Env)
	if err != nil {
		return err
	}
	env.SetAllocDir(filepath.Join("/", allocdir.SharedAllocName))
	env.SetTaskLocalDir(filepath.Join("/", allocdir.TaskLocal))
	e.cmd.Env = env.List()

	return nil
}

func (e *LinuxExecutor) Start() error {
	// Run as "nobody" user so we don't leak root privilege to the spawned
	// process.
	if err := e.runAs("nobody"); err == nil && e.user != nil {
		e.cmd.SetUID(e.user.Uid)
		e.cmd.SetGID(e.user.Gid)
	}

	// Parse the commands arguments and replace instances of Nomad environment
	// variables.
	envVars, err := environment.ParseFromList(e.Cmd.Env)
	if err != nil {
		return err
	}

	parsedPath, err := args.ParseAndReplace(e.cmd.Path, envVars.Map())
	if err != nil {
		return err
	} else if len(parsedPath) != 1 {
		return fmt.Errorf("couldn't properly parse command path: %v", e.cmd.Path)
	}
	e.cmd.Path = parsedPath[0]

	combined := strings.Join(e.Cmd.Args, " ")
	parsed, err := args.ParseAndReplace(combined, envVars.Map())
	if err != nil {
		return err
	}
	e.Cmd.Args = parsed

	spawnState := filepath.Join(e.allocDir, fmt.Sprintf("%s_%s", e.taskName, "exit_status"))
	e.spawn = spawn.NewSpawner(spawnState)
	e.spawn.SetCommand(&e.cmd.Cmd)
	e.spawn.SetChroot(e.taskDir)
	e.spawn.SetLogs(&spawn.Logs{
		Stdout: filepath.Join(e.taskDir, allocdir.TaskLocal, fmt.Sprintf("%v.stdout", e.taskName)),
		Stderr: filepath.Join(e.taskDir, allocdir.TaskLocal, fmt.Sprintf("%v.stderr", e.taskName)),
		Stdin:  os.DevNull,
	})

	enterCgroup := func(pid int) error {
		// Join the spawn-daemon to the cgroup.
		manager := e.getCgroupManager(e.groups)

		// Apply will place the spawn dameon into the created cgroups.
		if err := manager.Apply(pid); err != nil {
			return fmt.Errorf("Failed to join spawn-daemon to the cgroup (%+v): %v", e.groups, err)
		}

		return nil
	}

	return e.spawn.Spawn(enterCgroup)
}

func (e *LinuxExecutor) ConfigureTaskDir(taskName string, alloc *allocdir.AllocDir) error {
	e.taskName = taskName
	taskDir, ok := alloc.TaskDirs[taskName]
	if !ok {
		fmt.Errorf("Couldn't find task directory for task %v", taskName)
	}
	e.taskDir = taskDir

	if err := alloc.MountSharedDir(taskName); err != nil {
		return err
	}

	if err := alloc.Embed(taskName, chrootEnv); err != nil {
		return err
	}

	// Mount dev
	dev := filepath.Join(taskDir, "dev")
	if err := os.Mkdir(dev, 0777); err != nil {
		return fmt.Errorf("Mkdir(%v) failed: %v", dev, err)
	}

	if err := syscall.Mount("", dev, "devtmpfs", syscall.MS_RDONLY, ""); err != nil {
		return fmt.Errorf("Couldn't mount /dev to %v: %v", dev, err)
	}

	// Mount proc
	proc := filepath.Join(taskDir, "proc")
	if err := os.Mkdir(proc, 0777); err != nil {
		return fmt.Errorf("Mkdir(%v) failed: %v", proc, err)
	}

	if err := syscall.Mount("", proc, "proc", syscall.MS_RDONLY, ""); err != nil {
		return fmt.Errorf("Couldn't mount /proc to %v: %v", proc, err)
	}

	// Set the tasks AllocDir environment variable.
	env, err := environment.ParseFromList(e.Cmd.Env)
	if err != nil {
		return err
	}
	env.SetAllocDir(filepath.Join("/", allocdir.SharedAllocName))
	env.SetTaskLocalDir(filepath.Join("/", allocdir.TaskLocal))
	e.Cmd.Env = env.List()

	e.alloc = alloc
	e.mounts = true
	return nil
}