@@ -2,7 +2,6 @@ package plugins

 import (

 	"encoding/json"

-	"errors"

 	"fmt"

 	"io/ioutil"

 	"net/url"

@@ -10,6 +9,8 @@ import (

 	"path/filepath"

 	"strings"

 	"sync"

+

+	"github.com/pkg/errors"

 )

 var (

@@ -28,30 +29,52 @@ func newLocalRegistry() localRegistry {

 // Scan scans all the plugin paths and returns all the names it found

 func Scan() ([]string, error) {

 	var names []string

-	if err := filepath.Walk(socketsPath, func(path string, fi os.FileInfo, err error) error {

-		if err != nil {

-			return nil

+	dirEntries, err := ioutil.ReadDir(socketsPath)

+	if err != nil && !os.IsNotExist(err) {

+		return nil, errors.Wrap(err, "error reading dir entries")

+	}

+

+	for _, fi := range dirEntries {

+		if fi.IsDir() {

+			fi, err = os.Stat(filepath.Join(socketsPath, fi.Name(), fi.Name()+".sock"))

+			if err != nil {

+				continue

+			}

 		}

 		if fi.Mode()&os.ModeSocket != 0 {

-			name := strings.TrimSuffix(fi.Name(), filepath.Ext(fi.Name()))

-			names = append(names, name)

+			names = append(names, strings.TrimSuffix(filepath.Base(fi.Name()), filepath.Ext(fi.Name())))

 		}

-		return nil

-	}); err != nil {

-		return nil, err

 	}

-	for _, path := range specsPaths {

-		if err := filepath.Walk(path, func(p string, fi os.FileInfo, err error) error {

-			if err != nil || fi.IsDir() {

-				return nil

+	for _, p := range specsPaths {

+		dirEntries, err := ioutil.ReadDir(p)

+		if err != nil && !os.IsNotExist(err) {

+			return nil, errors.Wrap(err, "error reading dir entries")

+		}

+

+		for _, fi := range dirEntries {

+			if fi.IsDir() {

+				infos, err := ioutil.ReadDir(filepath.Join(p, fi.Name()))

+				if err != nil {

+					continue

+				}

+

+				for _, info := range infos {

+					if strings.TrimSuffix(info.Name(), filepath.Ext(info.Name())) == fi.Name() {

+						fi = info

+						break

+					}

+				}

+			}

+

+			ext := filepath.Ext(fi.Name())

+			switch ext {

+			case ".spec", ".json":

+				plugin := strings.TrimSuffix(fi.Name(), ext)

+				names = append(names, plugin)

+			default:

 			}

-			name := strings.TrimSuffix(fi.Name(), filepath.Ext(fi.Name()))

-			names = append(names, name)

-			return nil

-		}); err != nil {

-			return nil, err

 		}

 	}

 	return names, nil

@@ -81,7 +104,7 @@ func (l *localRegistry) Plugin(name string) (*Plugin, error) {

 			return readPluginInfo(name, p)

 		}

 	}

-	return nil, ErrNotFound

+	return nil, errors.Wrapf(ErrNotFound, "could not find plugin %s in v1 plugin registry", name)

 }

 func readPluginInfo(name, path string) (*Plugin, error) {

@@ -97,7 +97,63 @@ func TestScan(t *testing.T) {

 	if err != nil {

 		t.Fatal(err)

 	}

+	if len(pluginNamesNotEmpty) != 1 {

+		t.Fatalf("expected 1 plugin entry: %v", pluginNamesNotEmpty)

+	}

 	if p.Name() != pluginNamesNotEmpty[0] {

 		t.Fatalf("Unable to scan plugin with name %s", p.name)

 	}

 }

+

+func TestScanNotPlugins(t *testing.T) {

+	tmpdir, unregister := Setup(t)

+	defer unregister()

+

+	// not that `Setup()` above sets the sockets path and spec path dirs, which

+	// `Scan()` uses to find plugins to the returned `tmpdir`

+

+	notPlugin := filepath.Join(tmpdir, "not-a-plugin")

+	if err := os.MkdirAll(notPlugin, 0700); err != nil {

+		t.Fatal(err)

+	}

+

+	// this is named differently than the dir it's in, so the scanner should ignore it

+	l, err := net.Listen("unix", filepath.Join(notPlugin, "foo.sock"))

+	if err != nil {

+		t.Fatal(err)

+	}

+	defer l.Close()

+

+	// same let's test a spec path

+	f, err := os.Create(filepath.Join(notPlugin, "foo.spec"))

+	if err != nil {

+		t.Fatal(err)

+	}

+	defer f.Close()

+

+	names, err := Scan()

+	if err != nil {

+		t.Fatal(err)

+	}

+	if len(names) != 0 {

+		t.Fatalf("expected no plugins, got %v", names)

+	}

+

+	// Just as a sanity check, let's make an entry that the scanner should read

+	f, err = os.Create(filepath.Join(notPlugin, "not-a-plugin.spec"))

+	if err != nil {

+		t.Fatal(err)

+	}

+	defer f.Close()

+

+	names, err = Scan()

+	if err != nil {

+		t.Fatal(err)

+	}

+	if len(names) != 1 {

+		t.Fatalf("expected 1 entry in result: %v", names)

+	}

+	if names[0] != "not-a-plugin" {

+		t.Fatalf("expected plugin named `not-a-plugin`, got: %s", names[0])

+	}

+}

@@ -3,7 +3,6 @@ package plugins

 import (

 	"bytes"

 	"encoding/json"

-	"errors"

 	"io"

 	"io/ioutil"

 	"net/http"

@@ -15,6 +14,7 @@ import (

 	"github.com/docker/docker/pkg/plugins/transport"

 	"github.com/docker/go-connections/tlsconfig"

+	"github.com/pkg/errors"

 	"github.com/stretchr/testify/assert"

 )

@@ -78,11 +78,11 @@ func TestGet(t *testing.T) {

 	// check negative case where plugin fruit doesn't implement banana

 	_, err = Get("fruit", "banana")

-	assert.Equal(t, err, ErrNotImplements)

+	assert.Equal(t, errors.Cause(err), ErrNotImplements)

 	// check negative case where plugin vegetable doesn't exist

 	_, err = Get("vegetable", "potato")

-	assert.Equal(t, err, ErrNotFound)

+	assert.Equal(t, errors.Cause(err), ErrNotFound)

 }