Add --discovery-mode to nvidia-ctk cdi generate command

This change adds --discovery-mode flag to the nvidia-ctk cdi generate
command and plumbs this through to the CDI API.

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

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

@@ -36,6 +36,8 @@ import (
 )
 
 const (
+	discoveryModeNVML = "nvml"
+
 	formatJSON = "json"
 	formatYAML = "yaml"
 )
@@ -50,6 +52,7 @@ type config struct {
 	deviceNameStrategy string
 	driverRoot         string
 	nvidiaCTKPath      string
+	discoveryMode      string
 }
 
 // NewCommand constructs a generate-cdi command with the specified logger
@@ -88,6 +91,12 @@ func (m command) build() *cli.Command {
 			Value:       formatYAML,
 			Destination: &cfg.format,
 		},
+		&cli.StringFlag{
+			Name:        "discovery-mode",
+			Usage:       "The mode to use when discovering the available entities. One of [nvml]",
+			Value:       discoveryModeNVML,
+			Destination: &cfg.discoveryMode,
+		},
 		&cli.StringFlag{
 			Name:        "device-name-strategy",
 			Usage:       "Specify the strategy for generating device names. One of [index | uuid | type-index]",
@@ -118,6 +127,13 @@ func (m command) validateFlags(r *cli.Context, cfg *config) error {
 		return fmt.Errorf("invalid output format: %v", cfg.format)
 	}
 
+	cfg.discoveryMode = strings.ToLower(cfg.discoveryMode)
+	switch cfg.discoveryMode {
+	case discoveryModeNVML:
+	default:
+		return fmt.Errorf("invalid discovery mode: %v", cfg.discoveryMode)
+	}
+
 	_, err := nvcdi.NewDeviceNamer(cfg.deviceNameStrategy)
 	if err != nil {
 		return err
@@ -229,6 +245,7 @@ func (m command) generateSpec(cfg *config) (*specs.Spec, error) {
 		nvcdi.WithDeviceNamer(deviceNamer),
 		nvcdi.WithDeviceLib(devicelib),
 		nvcdi.WithNvmlLib(nvmllib),
+		nvcdi.WithMode(string(cfg.discoveryMode)),
 	)
 
 	deviceSpecs, err := cdilib.GetAllDeviceSpecs()
@@ -298,3 +315,5 @@ func createParentDirsIfRequired(filename string) error {
 	}
 	return os.MkdirAll(dir, 0755)
 }
+
+type discoveryMode string