func findDiagnosticLogs(c *session.Session) ([]entryReader, error) {
	defer trace.End(trace.Begin(""))

	// When connected to VC, we collect vpxd.log and hostd.log for all cluster hosts attached to the datastore.
	// When connected to ESX, we just collect hostd.log.
	const (
		vpxdKey  = "vpxd:vpxd.log"
		hostdKey = "hostd"
	)

	var logs []entryReader
	var err error

	if c.IsVC() {
		logs = append(logs, dlogReader{c, vpxdKey, nil})

		var hosts []*object.HostSystem
		if c.Cluster == nil && c.Host != nil {
			hosts = []*object.HostSystem{c.Host}
		} else {
			hosts, err = c.Datastore.AttachedClusterHosts(context.TODO(), c.Cluster)
			if err != nil {
				return nil, err
			}
		}

		for _, host := range hosts {
			logs = append(logs, dlogReader{c, hostdKey, host})
		}
	} else {
		logs = append(logs, dlogReader{c, hostdKey, nil})
	}

	return logs, nil
}

// NewDatastore returns a Datastore.
// ctx is a context,
// s is an authenticated session
// ds is the vsphere datastore
// rootdir is the top level directory to root all data.  If root does not exist,
// it will be created.  If it already exists, NOOP. This cannot be empty.
func NewDatastore(ctx context.Context, s *session.Session, ds *object.Datastore, rootdir string) (*Datastore, error) {

	d := &Datastore{
		ds: ds,
		s:  s,
		fm: object.NewFileManager(s.Vim25()),
	}

	if strings.HasPrefix(rootdir, "/") {
		rootdir = strings.TrimPrefix(rootdir, "/")
	}

	// Get the root directory element split from the rest of the path (if there is one)
	root := strings.SplitN(rootdir, "/", 2)

	// Create the first element.  This handles vsan vmfs top level dirs.
	if err := d.mkRootDir(ctx, root[0]); err != nil {
		log.Infof("error creating root directory %s: %s", rootdir, err)
		return nil, err
	}

	// Create the rest conventionally
	if len(root) > 1 {
		r, err := d.Mkdir(ctx, true, root[1])
		if err != nil {
			return nil, err
		}
		d.RootURL = r
	}

	log.Infof("Datastore path is %s", d.RootURL)
	return d, nil
}

func createAppliance(ctx context.Context, sess *session.Session, conf *config.VirtualContainerHostConfigSpec, vConf *data.InstallerData, hasErr bool, t *testing.T) {
	var err error

	d := &Dispatcher{
		session: sess,
		ctx:     ctx,
		isVC:    sess.IsVC(),
		force:   false,
	}
	delete(conf.Networks, "bridge") // FIXME: cannot create bridge network in simulator
	if d.isVC {
		if d.vchVapp, err = d.createVApp(conf, vConf); err != nil {
			// FIXME: Got error: ServerFaultCode: ResourcePool:resourcepool-14 does not implement: CreateVApp. Simulator need to implement CreateVApp
			//			t.Errorf("Unable to create virtual app: %s", err)
		}
	}
	if d.vchPool, err = d.createResourcePool(conf, vConf); err != nil {
		t.Errorf("Unable to create resource pool: %s", err)
	}

	spec, err := d.createApplianceSpec(conf, vConf)
	if err != nil {
		t.Errorf("Unable to create appliance spec: %s", err)
		return
	}

	// create appliance VM
	info, err := tasks.WaitForResult(d.ctx, func(ctx context.Context) (tasks.ResultWaiter, error) {
		return d.session.Folders(ctx).VmFolder.CreateVM(ctx, *spec, d.vchPool, d.session.Host)
	})
	// get VM reference and save it
	moref := info.Result.(types.ManagedObjectReference)
	conf.SetMoref(&moref)
	obj, err := d.session.Finder.ObjectReference(d.ctx, moref)
	if err != nil {
		t.Errorf("Failed to reacquire reference to appliance VM after creation: %s", err)
		return
	}
	gvm, ok := obj.(*object.VirtualMachine)
	if !ok {
		t.Errorf("Required reference after appliance creation was not for a VM: %T", obj)
		return
	}

	vm2 := vm.NewVirtualMachineFromVM(d.ctx, d.session, gvm)
	uuid, err := vm2.UUID(d.ctx)
	if err != nil {
		t.Errorf("Failed to get VM UUID: %s", err)
		return
	}
	t.Logf("uuid: %s", uuid)

	// leverage create volume method to create image datastore
	conf.VolumeLocations["images-store"], _ = url.Parse(fmt.Sprintf("ds://LocalDS_0/VIC/%s/images", uuid))

	if err := d.createVolumeStores(conf); err != nil {
		t.Errorf("Unable to create volume stores: %s", err)
		return
	}
}

func TestMain(t *testing.T) {

	ctx := context.Background()

	for i, model := range []*simulator.Model{simulator.ESX(), simulator.VPX()} {
		t.Logf("%d", i)
		defer model.Remove()
		err := model.Create()
		if err != nil {
			t.Fatal(err)
		}

		s := model.Service.NewServer()
		defer s.Close()

		s.URL.User = url.UserPassword("user", "pass")
		t.Logf("server URL: %s", s.URL)

		var sess *session.Session
		if i == 0 {
			sess, err = getESXSession(ctx, s.URL.String())
		} else {
			sess, err = getVPXSession(ctx, s.URL.String())
		}
		if err != nil {
			t.Fatal(err)
		}
		defer sess.Logout(ctx)
		testGetChildrenVMs(ctx, sess, t)
		testGetChildVM(ctx, sess, t)
		testFindResourcePool(ctx, sess, t)
		testGetCluster(ctx, sess, t)
	}
}

func Init(ctx context.Context, sess *session.Session, source extraconfig.DataSource, sink extraconfig.DataSink) error {
	trace.End(trace.Begin(""))

	initializer.once.Do(func() {
		var err error
		defer func() {
			initializer.err = err
		}()

		f := find.NewFinder(sess.Vim25(), false)

		var config Configuration
		config.sink = sink
		config.source = source
		config.Decode()
		config.PortGroups = make(map[string]object.NetworkReference)

		log.Debugf("Decoded VCH config for network: %#v", config)
		for nn, n := range config.ContainerNetworks {
			pgref := new(types.ManagedObjectReference)
			if !pgref.FromString(n.ID) {
				log.Warnf("Could not reacquire object reference from id for network %s: %s", nn, n.ID)
			}

			var r object.Reference
			if r, err = f.ObjectReference(ctx, *pgref); err != nil {
				log.Warnf("could not get network reference for %s network: %s", nn, err)
				err = nil
				continue
			}

			config.PortGroups[nn] = r.(object.NetworkReference)
		}

		// make sure a NIC attached to the bridge network exists
		config.BridgeLink, err = getBridgeLink(&config)
		if err != nil {
			return
		}

		var kv kvstore.KeyValueStore
		kv, err = store.NewDatastoreKeyValue(ctx, sess, "network.contexts.default")
		if err != nil {
			return
		}

		var netctx *Context
		if netctx, err = NewContext(&config, kv); err != nil {
			return
		}

		if err = engageContext(ctx, netctx, exec.Config.EventManager); err == nil {
			DefaultContext = netctx
			log.Infof("Default network context allocated")
		}
	})

	return initializer.err
}

func rm(t *testing.T, client *session.Session, name string) {
	t.Logf("deleting %s", name)
	fm := object.NewFileManager(client.Vim25())
	task, err := fm.DeleteDatastoreFile(context.TODO(), name, client.Datacenter)
	if !assert.NoError(t, err) {
		return
	}
	_, _ = task.WaitForResult(context.TODO(), nil)
}

// populate the vm attributes for the specified morefs
func populateVMAttributes(ctx context.Context, sess *session.Session, refs []types.ManagedObjectReference) ([]mo.VirtualMachine, error) {
	var vms []mo.VirtualMachine

	// current attributes we care about
	attrib := []string{"config", "runtime.powerState", "summary"}

	// populate the vm properties
	err := sess.Retrieve(ctx, refs, attrib, &vms)
	return vms, err
}

func createNodes(ctx context.Context, sess *session.Session, pool *object.ResourcePool, node *Node, base string) error {
	log.Debugf("create node %+v", node)
	if node == nil {
		return nil
	}
	spec := simulator.NewResourceConfigSpec()
	node.Name = fmt.Sprintf("%s-%s", base, node.Name)
	switch node.Kind {
	case rpNode:
		child, err := pool.Create(ctx, node.Name, spec)
		if err != nil {
			return err
		}
		for _, childNode := range node.Children {
			return createNodes(ctx, sess, child, childNode, base)
		}
	case vappNode:
		confSpec := types.VAppConfigSpec{
			VmConfigSpec: types.VmConfigSpec{},
		}
		vapp, err := pool.CreateVApp(ctx, node.Name, spec, confSpec, nil)
		if err != nil {
			return err
		}
		config := types.VirtualMachineConfigSpec{
			Name:    node.Name,
			GuestId: string(types.VirtualMachineGuestOsIdentifierOtherGuest),
			Files: &types.VirtualMachineFileInfo{
				VmPathName: fmt.Sprintf("[LocalDS_0] %s", node.Name),
			},
		}
		if _, err = tasks.WaitForResult(ctx, func(ctx context.Context) (tasks.Task, error) {
			return vapp.CreateChildVM_Task(ctx, config, nil)
		}); err != nil {
			return err
		}
	case vmNode:
		config := types.VirtualMachineConfigSpec{
			Name:    node.Name,
			GuestId: string(types.VirtualMachineGuestOsIdentifierOtherGuest),
			Files: &types.VirtualMachineFileInfo{
				VmPathName: fmt.Sprintf("[LocalDS_0] %s", node.Name),
			},
		}
		folder := sess.Folders(ctx).VmFolder
		if _, err := tasks.WaitForResult(ctx, func(ctx context.Context) (tasks.Task, error) {
			return folder.CreateVM(ctx, config, pool, nil)
		}); err != nil {
			return err
		}
	default:
		return nil
	}
	return nil
}

func testDeleteVolumeStores(ctx context.Context, sess *session.Session, conf *config.VirtualContainerHostConfigSpec, numVols int, t *testing.T) {
	d := &Dispatcher{
		session: sess,
		ctx:     ctx,
		isVC:    sess.IsVC(),
		force:   true,
	}

	if removed := d.deleteVolumeStoreIfForced(conf); removed != numVols {
		t.Errorf("Did not successfully remove all specified volumes")
	}

}

// NewDispatcher creates a dispatcher that can act upon VIC management operations.
// clientCert is an optional client certificate to allow interaction with the Docker API for verification
// force will ignore some errors
func NewDispatcher(ctx context.Context, s *session.Session, conf *config.VirtualContainerHostConfigSpec, force bool) *Dispatcher {
	defer trace.End(trace.Begin(""))
	isVC := s.IsVC()
	e := &Dispatcher{
		session: s,
		ctx:     ctx,
		isVC:    isVC,
		force:   force,
	}
	if conf != nil {
		e.InitDiagnosticLogs(conf)
	}
	return e
}

// FIXME: Failed to find IDE controller in simulator, so create appliance failed
func testCreateAppliance(ctx context.Context, sess *session.Session, conf *config.VirtualContainerHostConfigSpec, vConf *data.InstallerData, hasErr bool, t *testing.T) {
	d := &Dispatcher{
		session: sess,
		ctx:     ctx,
		isVC:    sess.IsVC(),
		force:   false,
	}
	delete(conf.Networks, "bridge") // FIXME: cannot create bridge network right now
	d.vchPool = d.session.Pool
	err := d.createAppliance(conf, vConf)
	if err != nil {
		t.Logf("Expected error: %s", err)
	}
}

// NewDiagnosticManager returns a new DiagnosticManager object
func NewDiagnosticManager(session *session.Session) *Manager {
	return &Manager{
		DiagnosticManager: object.NewDiagnosticManager(
			session.Vim25(),
		),
		Session: session,
	}
}

// NewResourcePool returns a New ResourcePool object
func NewVirtualApp(ctx context.Context, session *session.Session, moref types.ManagedObjectReference) *VirtualApp {
	return &VirtualApp{
		VirtualApp: object.NewVirtualApp(
			session.Vim25(),
			moref,
		),
		Session: session,
	}
}

// GetSelf gets VirtualMachine reference for the VM this process is running on
func GetSelf(ctx context.Context, s *session.Session) (*vm.VirtualMachine, error) {
	u, err := UUID()
	if err != nil {
		return nil, err
	}

	search := object.NewSearchIndex(s.Vim25())
	ref, err := search.FindByUuid(ctx, s.Datacenter, u, true, nil)
	if err != nil {
		return nil, err
	}

	if ref == nil {
		return nil, fmt.Errorf("can't find the hosting vm")
	}

	return vm.NewVirtualMachine(ctx, s, ref.Reference()), nil
}

// NewResourcePool returns a New ResourcePool object
func NewResourcePool(ctx context.Context, session *session.Session, moref types.ManagedObjectReference) *ResourcePool {
	return &ResourcePool{
		ResourcePool: object.NewResourcePool(
			session.Vim25(),
			moref,
		),
		Session: session,
	}
}

func isManagedbyVCH(sess *session.Session, moref types.ManagedObjectReference) bool {
	var vm mo.VirtualMachine

	// current attributes we care about
	attrib := []string{"resourcePool"}

	// populate the vm properties
	ctx := context.Background()
	if err := sess.RetrieveOne(ctx, moref, attrib, &vm); err != nil {
		log.Errorf("Failed to query registered vm object %s: %s", moref.String(), err)
		return false
	}
	if *vm.ResourcePool != Config.ResourcePool.Reference() {
		log.Debugf("container vm %q does not belong to this VCH, ignoring", vm.Config.Name)
		return false
	}
	return true
}

func (c *Container) Update(ctx context.Context, sess *session.Session) (*executor.ExecutorConfig, error) {
	defer trace.End(trace.Begin("Container.Update"))
	c.Lock()
	defer c.Unlock()

	if c.vm == nil {
		return nil, fmt.Errorf("container does not have a vm")
	}

	var vm []mo.VirtualMachine

	if err := sess.Retrieve(ctx, []types.ManagedObjectReference{c.vm.Reference()}, []string{"config"}, &vm); err != nil {
		return nil, err
	}

	extraconfig.Decode(vmomi.OptionValueSource(vm[0].Config.ExtraConfig), c.ExecConfig)
	return c.ExecConfig, nil
}

func testCreateNetwork(ctx context.Context, sess *session.Session, conf *config.VirtualContainerHostConfigSpec, t *testing.T) {
	d := &Dispatcher{
		session: sess,
		ctx:     ctx,
		isVC:    sess.IsVC(),
		force:   false,
	}

	err := d.createBridgeNetwork(conf)
	if d.isVC && err != nil {
		t.Logf("Got exepcted err: %s", err)
		return
	}
	if d.isVC {
		t.Errorf("Should not create network in VC")
		return
	}
	if err != nil {
		t.Errorf("Unexpected error: %s", err)
	}
}

func testCreateVolumeStores(ctx context.Context, sess *session.Session, conf *config.VirtualContainerHostConfigSpec, hasErr bool, t *testing.T) {
	d := &Dispatcher{
		session: sess,
		ctx:     ctx,
		isVC:    sess.IsVC(),
		force:   false,
	}

	err := d.createVolumeStores(conf)
	if hasErr && err != nil {
		t.Logf("Got exepcted err: %s", err)
		return
	}
	if hasErr {
		t.Errorf("Should have error, but got success")
		return
	}
	if err != nil {
		t.Errorf("Unexpected error: %s", err)
	}
}

func createTestData(ctx context.Context, sess *session.Session, prefix string) error {
	dcs, err := sess.Finder.DatacenterList(ctx, "*")
	if err != nil {
		return err
	}
	for _, dc := range dcs {
		sess.Finder.SetDatacenter(dc)
		sess.Datacenter = dc
		resources := &Node{
			Kind: rpNode,
			Name: prefix + "Root",
			Children: []*Node{
				{
					Kind: rpNode,
					Name: prefix + "pool1",
					Children: []*Node{
						{
							Kind: vmNode,
							Name: prefix + "pool1",
						},
						{
							Kind: rpNode,
							Name: prefix + "pool1-2",
							Children: []*Node{
								{
									Kind: rpNode,
									Name: prefix + "pool1-2-1",
									Children: []*Node{
										{
											Kind: vmNode,
											Name: prefix + "vch1-2-1",
										},
									},
								},
							},
						},
					},
				},
				{
					Kind: vmNode,
					Name: prefix + "vch2",
				},
			},
		}
		if err = createResources(ctx, sess, resources); err != nil {
			return err
		}
	}
	return nil
}