Merge branch 'CNT-3707/add-root-flag' into 'main'

Add --root flag to nvidia-ctk cdi generate command

See merge request nvidia/container-toolkit/container-toolkit!256

cmd/nvidia-ctk/cdi/generate/device-folder-permissions.go

@@ -17,10 +17,7 @@
 package generate
 
 import (
-	"fmt"
-	"os"
 	"path/filepath"
-	"strings"
 
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/discover"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/lookup"
@@ -31,7 +28,7 @@ import (
 type deviceFolderPermissions struct {
 	logger  *logrus.Logger
 	root    string
-	foldersByMode map[string][]string
+	folders []string
 }
 
 var _ discover.Discover = (*deviceFolderPermissions)(nil)
@@ -39,41 +36,38 @@ var _ discover.Discover = (*deviceFolderPermissions)(nil)
 // NewDeviceFolderPermissionHookDiscoverer creates a discoverer that can be used to update the permissions for the parent folders of nested device nodes from the specified set of device specs.
 // This works around an issue with rootless podman when using crun as a low-level runtime.
 // See https://github.com/containers/crun/issues/1047
-// TODO: This currently assumes `root == ""`
+// The nested devices that are applicable to the NVIDIA GPU devices are:
+//   - DRM devices at /dev/dri/*
+//   - NVIDIA Caps devices at /dev/nvidia-caps/*
 func NewDeviceFolderPermissionHookDiscoverer(logger *logrus.Logger, root string, deviceSpecs []specs.Device) (discover.Discover, error) {
-	var paths []string
+	var folders []string
 	seen := make(map[string]bool)
-
 	for _, device := range deviceSpecs {
 		for _, dn := range device.ContainerEdits.DeviceNodes {
-			if !strings.HasPrefix(dn.Path, "/dev") {
-				logger.Warningf("Skipping unexpected device folder path for device %v", dn)
-				continue
-			}
-			for df := filepath.Dir(dn.Path); df != "/dev"; df = filepath.Dir(df) {
+			df := filepath.Dir(dn.Path)
 			if seen[df] {
 				continue
 			}
-				paths = append(paths, df)
+			// We only consider the special case paths
+			if df != "/dev/dri" && df != "/dev/nvidia-caps" {
+				continue
+			}
+			folders = append(folders, df)
 			seen[df] = true
 		}
+		if len(folders) == 2 {
+			break
 		}
 	}
 
-	foldersByMode := make(map[string][]string)
-	for _, p := range paths {
-		info, err := os.Stat(p)
-		if err != nil {
-			return nil, fmt.Errorf("failed to get info for path %v: %v", p, err)
-		}
-		mode := fmt.Sprintf("%o", info.Mode().Perm())
-		foldersByMode[mode] = append(foldersByMode[mode], p)
+	if len(folders) == 0 {
+		return discover.None{}, nil
 	}
 
 	d := &deviceFolderPermissions{
 		logger:  logger,
 		root:    root,
-		foldersByMode: foldersByMode,
+		folders: folders,
 	}
 
 	return d, nil
@@ -84,31 +78,26 @@ func (d *deviceFolderPermissions) Devices() ([]discover.Device, error) {
 	return nil, nil
 }
 
-// Hooks returns a set of hooks that sets the file modes of parent folders for device nodes.
-// One hook is returned per mode.
+// Hooks returns a set of hooks that sets the file mode to 755 of parent folders for nested device nodes.
 func (d *deviceFolderPermissions) Hooks() ([]discover.Hook, error) {
-	locator := lookup.NewExecutableLocator(d.logger, d.root)
-
-	var hooks []discover.Hook
-	for mode, folders := range d.foldersByMode {
-		args := []string{"--mode", mode}
-		for _, folder := range folders {
-			args = append(args, "--path", folder)
+	if len(d.folders) == 0 {
+		return nil, nil
 	}
 
+	args := []string{"--mode", "755"}
+	for _, folder := range d.folders {
+		args = append(args, "--path", folder)
+	}
 	hook := discover.CreateNvidiaCTKHook(
 		d.logger,
-			locator,
+		lookup.NewExecutableLocator(d.logger, d.root),
 		nvidiaCTKExecutable,
 		nvidiaCTKDefaultFilePath,
 		"chmod",
 		args...,
 	)
 
-		hooks = append(hooks, hook)
-	}
-
-	return hooks, nil
+	return []discover.Hook{hook}, nil
 }
 
 // Mounts are empty for this discoverer

cmd/nvidia-ctk/cdi/generate/generate.go

@@ -49,6 +49,7 @@ type command struct {
 type config struct {
 	output string
 	format string
+	root   string
 }
 
 // NewCommand constructs a generate-cdi command with the specified logger
@@ -87,6 +88,11 @@ func (m command) build() *cli.Command {
 			Value:       formatYAML,
 			Destination: &cfg.format,
 		},
+		&cli.StringFlag{
+			Name:        "root",
+			Usage:       "Specify the root to use when discovering the entities that should be included in the CDI specification.",
+			Destination: &cfg.root,
+		},
 	}
 
 	return &c
@@ -105,7 +111,7 @@ func (m command) validateFlags(r *cli.Context, cfg *config) error {
 }
 
 func (m command) run(c *cli.Context, cfg *config) error {
-	spec, err := m.generateSpec()
+	spec, err := m.generateSpec(cfg.root)
 	if err != nil {
 		return fmt.Errorf("failed to generate CDI spec: %v", err)
 	}
@@ -184,7 +190,7 @@ func writeToOutput(format string, data []byte, output io.Writer) error {
 	return nil
 }
 
-func (m command) generateSpec() (*specs.Spec, error) {
+func (m command) generateSpec(root string) (*specs.Spec, error) {
 	nvmllib := nvml.New()
 	if r := nvmllib.Init(); r != nvml.SUCCESS {
 		return nil, r
@@ -193,7 +199,7 @@ func (m command) generateSpec() (*specs.Spec, error) {
 
 	devicelib := device.New(device.WithNvml(nvmllib))
 
-	deviceSpecs, err := m.generateDeviceSpecs(devicelib)
+	deviceSpecs, err := m.generateDeviceSpecs(devicelib, root)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create device CDI specs: %v", err)
 	}
@@ -204,7 +210,7 @@ func (m command) generateSpec() (*specs.Spec, error) {
 
 	allEdits := cdi.ContainerEdits{}
 
-	ipcs, err := NewIPCDiscoverer(m.logger, "")
+	ipcs, err := NewIPCDiscoverer(m.logger, root)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create discoverer for IPC sockets: %v", err)
 	}
@@ -220,12 +226,12 @@ func (m command) generateSpec() (*specs.Spec, error) {
 
 	allEdits.Append(ipcEdits)
 
-	common, err := NewCommonDiscoverer(m.logger, "", nvmllib)
+	common, err := NewCommonDiscoverer(m.logger, root, nvmllib)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create discoverer for common entities: %v", err)
 	}
 
-	deviceFolderPermissionHooks, err := NewDeviceFolderPermissionHookDiscoverer(m.logger, "", deviceSpecs)
+	deviceFolderPermissionHooks, err := NewDeviceFolderPermissionHookDiscoverer(m.logger, root, deviceSpecs)
 	if err != nil {
 		return nil, fmt.Errorf("failed to generated permission hooks for device nodes: %v", err)
 	}
@@ -249,7 +255,7 @@ func (m command) generateSpec() (*specs.Spec, error) {
 	return &spec, nil
 }
 
-func (m command) generateDeviceSpecs(devicelib device.Interface) ([]specs.Device, error) {
+func (m command) generateDeviceSpecs(devicelib device.Interface, root string) ([]specs.Device, error) {
 	var deviceSpecs []specs.Device
 
 	err := devicelib.VisitDevices(func(i int, d device.Device) error {
@@ -260,7 +266,7 @@ func (m command) generateDeviceSpecs(devicelib device.Interface) ([]specs.Device
 		if isMigEnabled {
 			return nil
 		}
-		device, err := NewFullGPUDiscoverer(m.logger, "", d)
+		device, err := NewFullGPUDiscoverer(m.logger, root, d)
 		if err != nil {
 			return fmt.Errorf("failed to create device: %v", err)
 		}