Add support for mountPath as directory

README.md

@@ -94,6 +94,8 @@ Usage of generic-device-plugin:
                                   A "count" can be specified to allow a discovered device group to be scheduled multiple times.
                                   For example, to permit allocation of the FUSE device 10 times: {"name": "fuse", "groups": [{"count": 10, "paths": [{"path": "/dev/fuse"}]}]}
                                   Note: if omitted, "count" is assumed to be 1
+                                  If mountPath is a directory, the device will be mounted to the directory with the name of the device.
+                                  For example, to expose the serial devices to the /dev/serial directory: {"name": "serial", "groups": [{"paths": [{"path": "/dev/ttyUSB*", "mountPath": "/dev/serial/"}]}]}
       --domain string             The domain to use when when declaring devices. (default "squat.ai")
       --listen string             The address at which to listen for health and metrics. (default ":8080")
       --log-level string          Log level to use. Possible values: all, debug, info, warn, error, none (default "info")

config.go

@@ -46,7 +46,9 @@ For example, to allocate and mount an audio capture device: {"name": "capture",
 For example, to expose a CH340 serial converter: {"name": "ch340", "groups": [{"usb": [{"vendor": "1a86", "product": "7523"}]}]}
 A "count" can be specified to allow a discovered device group to be scheduled multiple times.
 For example, to permit allocation of the FUSE device 10 times: {"name": "fuse", "groups": [{"count": 10, "paths": [{"path": "/dev/fuse"}]}]}
-Note: if omitted, "count" is assumed to be 1`)
+Note: if omitted, "count" is assumed to be 1
+If mountPath is a directory, the device will be mounted to the directory with the name of the device.
+For example, to expose the serial devices to the /dev/serial directory: {"name": "serial", "groups": [{"paths": [{"path": "/dev/ttyUSB*", "mountPath": "/dev/serial/"}]}]}`)
 	flag.String("plugin-directory", v1beta1.DevicePluginPath, "The directory in which to create plugin sockets.")
 	flag.String("log-level", logLevelInfo, fmt.Sprintf("Log level to use. Possible values: %s", availableLogLevels))
 	flag.String("listen", ":8080", "The address at which to listen for health and metrics.")

deviceplugin/path.go

@@ -18,8 +18,10 @@ import (
 	"crypto/sha1"
 	"fmt"
 	"io/fs"
+	"path/filepath"
 	"sort"
 	"strconv"
+	"strings"
 
 	"k8s.io/kubelet/pkg/apis/deviceplugin/v1beta1"
 )
@@ -107,6 +109,9 @@ func (gp *GenericPlugin) discoverPath() ([]device, error) {
 					if mountPath == "" {
 						mountPath = paths[k][i]
 					}
+					if strings.HasSuffix(mountPath, "/") {
+						mountPath = mountPath + filepath.Base(paths[k][i])
+					}
 					switch path.Type {
 					case DevicePathType:
 						d.deviceSpecs = append(d.deviceSpecs, &v1beta1.DeviceSpec{

deviceplugin/path_test.go

@@ -121,6 +121,63 @@ func TestDiscoverPaths(t *testing.T) {
 			},
 			err: nil,
 		},
+		{
+			name: "multiple with mount directory",
+			ds: &DeviceSpec{
+				Name: "serial",
+				Groups: []*Group{
+					{
+						Paths: []*Path{
+							{
+								Path:      "/dev/ttyUSB*",
+								MountPath: "/dev/serial/",
+							},
+						},
+					},
+				},
+			},
+			fs: fstest.MapFS{
+				"dev/ttyUSB0": {},
+				"dev/ttyUSB1": {},
+				"dev/ttyUSB2": {},
+				"dev/ttyUSB3": {},
+			},
+			out: []device{
+				{
+					deviceSpecs: []*v1beta1.DeviceSpec{
+						{
+							ContainerPath: "/dev/serial/ttyUSB0",
+							HostPath:      "/dev/ttyUSB0",
+						},
+					},
+				},
+				{
+					deviceSpecs: []*v1beta1.DeviceSpec{
+						{
+							ContainerPath: "/dev/serial/ttyUSB1",
+							HostPath:      "/dev/ttyUSB1",
+						},
+					},
+				},
+				{
+					deviceSpecs: []*v1beta1.DeviceSpec{
+						{
+							ContainerPath: "/dev/serial/ttyUSB2",
+							HostPath:      "/dev/ttyUSB2",
+						},
+					},
+				},
+				{
+					deviceSpecs: []*v1beta1.DeviceSpec{
+						{
+							ContainerPath: "/dev/serial/ttyUSB3",
+							HostPath:      "/dev/ttyUSB3",
+						},
+					},
+				},
+			},
+			err: nil,
+		},
 		{
 			name: "only one exists",
 			ds: &DeviceSpec{