func (r *remote) Client(b Backend) (Client, error) {
	c := &client{
		clientCommon: clientCommon{
			backend:    b,
			containers: make(map[string]*container),
			locker:     locker.New(),
		},
		remote:        r,
		exitNotifiers: make(map[string]*exitNotifier),
	}

	r.Lock()
	r.clients = append(r.clients, c)
	r.Unlock()
	return c, nil
}

// New creates a new instance of network controller.
func New(cfgOptions ...config.Option) (NetworkController, error) {
	c := &controller{
		id:              stringid.GenerateRandomID(),
		cfg:             config.ParseConfigOptions(cfgOptions...),
		sandboxes:       sandboxTable{},
		svcRecords:      make(map[string]svcInfo),
		serviceBindings: make(map[serviceKey]*service),
		agentInitDone:   make(chan struct{}),
		networkLocker:   locker.New(),
	}

	if err := c.initStores(); err != nil {
		return nil, err
	}

	drvRegistry, err := drvregistry.New(c.getStore(datastore.LocalScope), c.getStore(datastore.GlobalScope), c.RegisterDriver, nil, c.cfg.PluginGetter)
	if err != nil {
		return nil, err
	}

	for _, i := range getInitializers() {
		var dcfg map[string]interface{}

		// External plugins don't need config passed through daemon. They can
		// bootstrap themselves
		if i.ntype != "remote" {
			dcfg = c.makeDriverConfig(i.ntype)
		}

		if err := drvRegistry.AddDriver(i.ntype, i.fn, dcfg); err != nil {
			return nil, err
		}
	}

	if err = initIPAMDrivers(drvRegistry, nil, c.getStore(datastore.GlobalScope)); err != nil {
		return nil, err
	}

	c.drvRegistry = drvRegistry

	if c.cfg != nil && c.cfg.Cluster.Watcher != nil {
		if err := c.initDiscovery(c.cfg.Cluster.Watcher); err != nil {
			// Failing to initialize discovery is a bad situation to be in.
			// But it cannot fail creating the Controller
			log.Errorf("Failed to Initialize Discovery : %v", err)
		}
	}

	c.WalkNetworks(populateSpecial)

	// Reserve pools first before doing cleanup. Otherwise the
	// cleanups of endpoint/network and sandbox below will
	// generate many unnecessary warnings
	c.reservePools()

	// Cleanup resources
	c.sandboxCleanup(c.cfg.ActiveSandboxes)
	c.cleanupLocalEndpoints()
	c.networkCleanup()

	if err := c.startExternalKeyListener(); err != nil {
		return nil, err
	}

	return c, nil
}