[no-relnote] Use string slice for devices in hook

Signed-off-by: Evan Lezar <elezar@nvidia.com>

cmd/nvidia-container-runtime-hook/container_config.go

@@ -7,7 +7,6 @@ import (
 	"os"
 	"path"
 	"path/filepath"
-	"strings"
 
 	"github.com/opencontainers/runtime-spec/specs-go"
 	"golang.org/x/mod/semver"
@@ -36,7 +35,7 @@ const (
 )
 
 type nvidiaConfig struct {
-	Devices            string
+	Devices            []string
 	MigConfigDevices   string
 	MigMonitorDevices  string
 	ImexChannels       string
@@ -172,34 +171,19 @@ func isPrivileged(s *Spec) bool {
 	return image.IsPrivileged(&fullSpec)
 }
 
-func getDevicesFromEnvvar(image image.CUDA, swarmResourceEnvvars []string) *string {
+func getDevicesFromEnvvar(image image.CUDA, swarmResourceEnvvars []string) []string {
 	// We check if the image has at least one of the Swarm resource envvars defined and use this
 	// if specified.
-	var hasSwarmEnvvar bool
 	for _, envvar := range swarmResourceEnvvars {
 		if image.HasEnvvar(envvar) {
-			hasSwarmEnvvar = true
+			return image.DevicesFromEnvvars(swarmResourceEnvvars...).List()
-			break
 		}
 	}
 
-	var devices []string
+	return image.DevicesFromEnvvars(envNVVisibleDevices).List()
-	if hasSwarmEnvvar {
-		devices = image.DevicesFromEnvvars(swarmResourceEnvvars...).List()
-	} else {
-		devices = image.DevicesFromEnvvars(envNVVisibleDevices).List()
-	}
-
-	if len(devices) == 0 {
-		return nil
-	}
-
-	devicesString := strings.Join(devices, ",")
-
-	return &devicesString
 }
 
-func getDevicesFromMounts(mounts []Mount) *string {
+func getDevicesFromMounts(mounts []Mount) []string {
 	var devices []string
 	for _, m := range mounts {
 		root := filepath.Clean(deviceListAsVolumeMountsRoot)
@@ -232,22 +216,21 @@ func getDevicesFromMounts(mounts []Mount) *string {
 		return nil
 	}
 
-	ret := strings.Join(devices, ",")
+	return devices
-	return &ret
 }
 
-func getDevices(hookConfig *HookConfig, image image.CUDA, mounts []Mount, privileged bool) *string {
+func getDevices(hookConfig *HookConfig, image image.CUDA, mounts []Mount, privileged bool) []string {
 	// If enabled, try and get the device list from volume mounts first
 	if hookConfig.AcceptDeviceListAsVolumeMounts {
 		devices := getDevicesFromMounts(mounts)
-		if devices != nil {
+		if len(devices) > 0 {
 			return devices
 		}
 	}
 
 	// Fallback to reading from the environment variable if privileges are correct
 	devices := getDevicesFromEnvvar(image, hookConfig.getSwarmResourceEnvvars())
-	if devices == nil {
+	if len(devices) == 0 {
 		return nil
 	}
 	if privileged || hookConfig.AcceptEnvvarUnprivileged {
@@ -314,11 +297,9 @@ func (c *HookConfig) getDriverCapabilities(cudaImage image.CUDA, legacyImage boo
 func getNvidiaConfig(hookConfig *HookConfig, image image.CUDA, mounts []Mount, privileged bool) *nvidiaConfig {
 	legacyImage := image.IsLegacy()
 
-	var devices string
+	devices := getDevices(hookConfig, image, mounts, privileged)
-	if d := getDevices(hookConfig, image, mounts, privileged); d != nil {
+	if len(devices) == 0 {
-		devices = *d
+		// empty devices means this is not a GPU container.
-	} else {
-		// 'nil' devices means this is not a GPU container.
 		return nil
 	}
 

cmd/nvidia-container-runtime-hook/container_config_test.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"fmt"
 	"path/filepath"
 	"testing"
 
@@ -38,7 +37,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "all",
+				Devices:            []string{"all"},
 				DriverCapabilities: image.SupportedDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -51,7 +50,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "all",
+				Devices:            []string{"all"},
 				DriverCapabilities: image.SupportedDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -82,7 +81,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "",
+				Devices:            []string{""},
 				DriverCapabilities: image.SupportedDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -95,7 +94,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: image.SupportedDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -109,7 +108,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -123,7 +122,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: image.SupportedDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -137,7 +136,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: "display,video",
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -153,7 +152,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: "display,video",
 				Requirements:       []string{"cuda>=9.0", "req0=true", "req1=false"},
 			},
@@ -170,7 +169,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: "display,video",
 				Requirements:       []string{},
 			},
@@ -200,7 +199,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "all",
+				Devices:            []string{"all"},
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -231,7 +230,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "",
+				Devices:            []string{""},
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -244,7 +243,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -258,7 +257,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -272,7 +271,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: image.SupportedDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -286,7 +285,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: "display,video",
 				Requirements:       []string{"cuda>=9.0"},
 			},
@@ -302,7 +301,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: "display,video",
 				Requirements:       []string{"cuda>=9.0", "req0=true", "req1=false"},
 			},
@@ -319,7 +318,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: false,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "gpu0,gpu1",
+				Devices:            []string{"gpu0", "gpu1"},
 				DriverCapabilities: "display,video",
 				Requirements:       []string{},
 			},
@@ -332,7 +331,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			privileged: false,
 
 			expectedConfig: &nvidiaConfig{
-				Devices:            "all",
+				Devices:            []string{"all"},
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 				Requirements:       []string{},
 			},
@@ -346,7 +345,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: true,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "all",
+				Devices:            []string{"all"},
 				MigConfigDevices:   "mig0,mig1",
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
@@ -371,7 +370,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 			},
 			privileged: true,
 			expectedConfig: &nvidiaConfig{
-				Devices:            "all",
+				Devices:            []string{"all"},
 				MigMonitorDevices:  "mig0,mig1",
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 				Requirements:       []string{"cuda>=9.0"},
@@ -398,7 +397,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 				SupportedDriverCapabilities: "video,display",
 			},
 			expectedConfig: &nvidiaConfig{
-				Devices:            "all",
+				Devices:            []string{"all"},
 				DriverCapabilities: "display,video",
 			},
 		},
@@ -413,7 +412,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 				SupportedDriverCapabilities: "video,display,compute,utility",
 			},
 			expectedConfig: &nvidiaConfig{
-				Devices:            "all",
+				Devices:            []string{"all"},
 				DriverCapabilities: "display,video",
 			},
 		},
@@ -427,7 +426,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 				SupportedDriverCapabilities: "video,display,utility,compute",
 			},
 			expectedConfig: &nvidiaConfig{
-				Devices:            "all",
+				Devices:            []string{"all"},
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 			},
 		},
@@ -443,7 +442,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 				SupportedDriverCapabilities: "video,display,utility,compute",
 			},
 			expectedConfig: &nvidiaConfig{
-				Devices:            "GPU1,GPU2",
+				Devices:            []string{"GPU1", "GPU2"},
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 			},
 		},
@@ -459,7 +458,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 				SupportedDriverCapabilities: "video,display,utility,compute",
 			},
 			expectedConfig: &nvidiaConfig{
-				Devices:            "GPU1,GPU2",
+				Devices:            []string{"GPU1", "GPU2"},
 				DriverCapabilities: image.DefaultDriverCapabilities.String(),
 			},
 		},
@@ -511,7 +510,7 @@ func TestGetDevicesFromMounts(t *testing.T) {
 	var tests = []struct {
 		description     string
 		mounts          []Mount
-		expectedDevices *string
+		expectedDevices []string
 	}{
 		{
 			description:     "No mounts",
@@ -560,7 +559,7 @@ func TestGetDevicesFromMounts(t *testing.T) {
 					Destination: filepath.Join(deviceListAsVolumeMountsRoot, "GPU1"),
 				},
 			},
-			expectedDevices: &[]string{"GPU0,GPU1"}[0],
+			expectedDevices: []string{"GPU0", "GPU1"},
 		},
 		{
 			description: "Discover 2 devices with slashes in the name",
@@ -574,7 +573,7 @@ func TestGetDevicesFromMounts(t *testing.T) {
 					Destination: filepath.Join(deviceListAsVolumeMountsRoot, "GPU1-MIG0/0/1"),
 				},
 			},
-			expectedDevices: &[]string{"GPU0-MIG0/0/1,GPU1-MIG0/0/1"}[0],
+			expectedDevices: []string{"GPU0-MIG0/0/1", "GPU1-MIG0/0/1"},
 		},
 	}
 	for _, tc := range tests {
@@ -593,7 +592,7 @@ func TestDeviceListSourcePriority(t *testing.T) {
 		privileged         bool
 		acceptUnprivileged bool
 		acceptMounts       bool
-		expectedDevices    *string
+		expectedDevices    []string
 	}{
 		{
 			description: "Mount devices, unprivileged, no accept unprivileged",
@@ -611,7 +610,7 @@ func TestDeviceListSourcePriority(t *testing.T) {
 			privileged:         false,
 			acceptUnprivileged: false,
 			acceptMounts:       true,
-			expectedDevices:    &[]string{"GPU0,GPU1"}[0],
+			expectedDevices:    []string{"GPU0", "GPU1"},
 		},
 		{
 			description:        "No mount devices, unprivileged, no accept unprivileged",
@@ -629,7 +628,7 @@ func TestDeviceListSourcePriority(t *testing.T) {
 			privileged:         true,
 			acceptUnprivileged: false,
 			acceptMounts:       true,
-			expectedDevices:    &[]string{"GPU0,GPU1"}[0],
+			expectedDevices:    []string{"GPU0", "GPU1"},
 		},
 		{
 			description:        "No mount devices, unprivileged, accept unprivileged",
@@ -638,7 +637,7 @@ func TestDeviceListSourcePriority(t *testing.T) {
 			privileged:         false,
 			acceptUnprivileged: true,
 			acceptMounts:       true,
-			expectedDevices:    &[]string{"GPU0,GPU1"}[0],
+			expectedDevices:    []string{"GPU0", "GPU1"},
 		},
 		{
 			description: "Mount devices, unprivileged, accept unprivileged, no accept mounts",
@@ -656,7 +655,7 @@ func TestDeviceListSourcePriority(t *testing.T) {
 			privileged:         false,
 			acceptUnprivileged: true,
 			acceptMounts:       false,
-			expectedDevices:    &[]string{"GPU2,GPU3"}[0],
+			expectedDevices:    []string{"GPU2", "GPU3"},
 		},
 		{
 			description: "Mount devices, unprivileged, no accept unprivileged, no accept mounts",
@@ -680,7 +679,7 @@ func TestDeviceListSourcePriority(t *testing.T) {
 	for _, tc := range tests {
 		t.Run(tc.description, func(t *testing.T) {
 			// Wrap the call to getDevices() in a closure.
-			var devices *string
+			var devices []string
 			getDevices := func() {
 				image, _ := image.New(
 					image.WithEnvMap(
@@ -704,8 +703,6 @@ func TestDeviceListSourcePriority(t *testing.T) {
 }
 
 func TestGetDevicesFromEnvvar(t *testing.T) {
-	all := "all"
-	empty := ""
 	envDockerResourceGPUs := "DOCKER_RESOURCE_GPUS"
 	gpuID := "GPU-12345"
 	anotherGPUID := "GPU-67890"
@@ -715,7 +712,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 		description          string
 		swarmResourceEnvvars []string
 		env                  map[string]string
-		expectedDevices      *string
+		expectedDevices      []string
 	}{
 		{
 			description: "empty env returns nil for non-legacy image",
@@ -737,14 +734,14 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 			env: map[string]string{
 				envNVVisibleDevices: "none",
 			},
-			expectedDevices: &empty,
+			expectedDevices: []string{""},
 		},
 		{
 			description: "NVIDIA_VISIBLE_DEVICES set returns value for non-legacy image",
 			env: map[string]string{
 				envNVVisibleDevices: gpuID,
 			},
-			expectedDevices: &gpuID,
+			expectedDevices: []string{gpuID},
 		},
 		{
 			description: "NVIDIA_VISIBLE_DEVICES set returns value for legacy image",
@@ -752,14 +749,14 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				envNVVisibleDevices: gpuID,
 				envCUDAVersion:      "legacy",
 			},
-			expectedDevices: &gpuID,
+			expectedDevices: []string{gpuID},
 		},
 		{
 			description: "empty env returns all for legacy image",
 			env: map[string]string{
 				envCUDAVersion: "legacy",
 			},
-			expectedDevices: &all,
+			expectedDevices: []string{"all"},
 		},
 		// Add the `DOCKER_RESOURCE_GPUS` envvar and ensure that this is ignored when
 		// not enabled
@@ -789,7 +786,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				envNVVisibleDevices:   "none",
 				envDockerResourceGPUs: anotherGPUID,
 			},
-			expectedDevices: &empty,
+			expectedDevices: []string{""},
 		},
 		{
 			description: "NVIDIA_VISIBLE_DEVICES set returns value for non-legacy image",
@@ -797,7 +794,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				envNVVisibleDevices:   gpuID,
 				envDockerResourceGPUs: anotherGPUID,
 			},
-			expectedDevices: &gpuID,
+			expectedDevices: []string{gpuID},
 		},
 		{
 			description: "NVIDIA_VISIBLE_DEVICES set returns value for legacy image",
@@ -806,7 +803,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				envDockerResourceGPUs: anotherGPUID,
 				envCUDAVersion:        "legacy",
 			},
-			expectedDevices: &gpuID,
+			expectedDevices: []string{gpuID},
 		},
 		{
 			description: "empty env returns all for legacy image",
@@ -814,7 +811,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				envDockerResourceGPUs: anotherGPUID,
 				envCUDAVersion:        "legacy",
 			},
-			expectedDevices: &all,
+			expectedDevices: []string{"all"},
 		},
 		// Add the `DOCKER_RESOURCE_GPUS` envvar and ensure that this is selected when
 		// enabled
@@ -842,7 +839,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 			env: map[string]string{
 				envDockerResourceGPUs: "none",
 			},
-			expectedDevices: &empty,
+			expectedDevices: []string{""},
 		},
 		{
 			description:          "DOCKER_RESOURCE_GPUS set returns value for non-legacy image",
@@ -850,7 +847,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 			env: map[string]string{
 				envDockerResourceGPUs: gpuID,
 			},
-			expectedDevices: &gpuID,
+			expectedDevices: []string{gpuID},
 		},
 		{
 			description:          "DOCKER_RESOURCE_GPUS set returns value for legacy image",
@@ -859,7 +856,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				envDockerResourceGPUs: gpuID,
 				envCUDAVersion:        "legacy",
 			},
-			expectedDevices: &gpuID,
+			expectedDevices: []string{gpuID},
 		},
 		{
 			description:          "DOCKER_RESOURCE_GPUS is selected if present",
@@ -867,7 +864,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 			env: map[string]string{
 				envDockerResourceGPUs: anotherGPUID,
 			},
-			expectedDevices: &anotherGPUID,
+			expectedDevices: []string{anotherGPUID},
 		},
 		{
 			description:          "DOCKER_RESOURCE_GPUS overrides NVIDIA_VISIBLE_DEVICES if present",
@@ -876,7 +873,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				envNVVisibleDevices:   gpuID,
 				envDockerResourceGPUs: anotherGPUID,
 			},
-			expectedDevices: &anotherGPUID,
+			expectedDevices: []string{anotherGPUID},
 		},
 		{
 			description:          "DOCKER_RESOURCE_GPUS_ADDITIONAL overrides NVIDIA_VISIBLE_DEVICES if present",
@@ -885,7 +882,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				envNVVisibleDevices:               gpuID,
 				"DOCKER_RESOURCE_GPUS_ADDITIONAL": anotherGPUID,
 			},
-			expectedDevices: &anotherGPUID,
+			expectedDevices: []string{anotherGPUID},
 		},
 		{
 			description:          "All available swarm resource envvars are selected and override NVIDIA_VISIBLE_DEVICES if present",
@@ -895,10 +892,7 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				"DOCKER_RESOURCE_GPUS":            thirdGPUID,
 				"DOCKER_RESOURCE_GPUS_ADDITIONAL": anotherGPUID,
 			},
-			expectedDevices: func() *string {
+			expectedDevices: []string{thirdGPUID, anotherGPUID},
-				result := fmt.Sprintf("%s,%s", thirdGPUID, anotherGPUID)
-				return &result
-			}(),
 		},
 		{
 			description:          "DOCKER_RESOURCE_GPUS_ADDITIONAL or DOCKER_RESOURCE_GPUS override NVIDIA_VISIBLE_DEVICES if present",
@@ -907,23 +901,17 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 				envNVVisibleDevices:               gpuID,
 				"DOCKER_RESOURCE_GPUS_ADDITIONAL": anotherGPUID,
 			},
-			expectedDevices: &anotherGPUID,
+			expectedDevices: []string{anotherGPUID},
 		},
 	}
 
-	for i, tc := range tests {
+	for _, tc := range tests {
 		t.Run(tc.description, func(t *testing.T) {
 			image, _ := image.New(
 				image.WithEnvMap(tc.env),
 			)
 			devices := getDevicesFromEnvvar(image, tc.swarmResourceEnvvars)
-			if tc.expectedDevices == nil {
+			require.EqualValues(t, tc.expectedDevices, devices)
-				require.Nil(t, devices, "%d: %v", i, tc)
-				return
-			}
-
-			require.NotNil(t, devices, "%d: %v", i, tc)
-			require.Equal(t, *tc.expectedDevices, *devices, "%d: %v", i, tc)
 		})
 	}
 }

cmd/nvidia-container-runtime-hook/main.go

@@ -120,8 +120,8 @@ func doPrestart() {
 	if cli.NoCgroups {
 		args = append(args, "--no-cgroups")
 	}
-	if len(nvidia.Devices) > 0 {
+	if devicesString := strings.Join(nvidia.Devices, ","); len(devicesString) > 0 {
-		args = append(args, fmt.Sprintf("--device=%s", nvidia.Devices))
+		args = append(args, fmt.Sprintf("--device=%s", devicesString))
 	}
 	if len(nvidia.MigConfigDevices) > 0 {
 		args = append(args, fmt.Sprintf("--mig-config=%s", nvidia.MigConfigDevices))