[no-relnote] Refactor CDI mode handling

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

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

@@ -104,10 +104,12 @@ func (m command) build() *cli.Command {
 			Destination: &opts.format,
 		},
 		&cli.StringFlag{
-			Name:        "mode",
-			Aliases:     []string{"discovery-mode"},
-			Usage:       "The mode to use when discovering the available entities. One of [auto | nvml | wsl]. If mode is set to 'auto' the mode will be determined based on the system configuration.",
-			Value:       nvcdi.ModeAuto,
+			Name:    "mode",
+			Aliases: []string{"discovery-mode"},
+			Usage: "The mode to use when discovering the available entities. " +
+				"One of [" + strings.Join(nvcdi.AllModes[string](), " | ") + "]. " +
+				"If mode is set to 'auto' the mode will be determined based on the system configuration.",
+			Value:       string(nvcdi.ModeAuto),
 			Destination: &opts.mode,
 		},
 		&cli.StringFlag{
@@ -184,13 +186,7 @@ func (m command) validateFlags(c *cli.Context, opts *options) error {
 	}
 
 	opts.mode = strings.ToLower(opts.mode)
-	switch opts.mode {
-	case nvcdi.ModeAuto:
-	case nvcdi.ModeCSV:
-	case nvcdi.ModeNvml:
-	case nvcdi.ModeWsl:
-	case nvcdi.ModeManagement:
-	default:
+	if !nvcdi.IsValidMode(opts.mode) {
 		return fmt.Errorf("invalid discovery mode: %v", opts.mode)
 	}
 

pkg/nvcdi/api.go

@@ -24,24 +24,6 @@ import (
 	"github.com/NVIDIA/nvidia-container-toolkit/pkg/nvcdi/spec"
 )
 
-const (
-	// ModeAuto configures the CDI spec generator to automatically detect the system configuration
-	ModeAuto = "auto"
-	// ModeNvml configures the CDI spec generator to use the NVML library.
-	ModeNvml = "nvml"
-	// ModeWsl configures the CDI spec generator to generate a WSL spec.
-	ModeWsl = "wsl"
-	// ModeManagement configures the CDI spec generator to generate a management spec.
-	ModeManagement = "management"
-	// ModeGds configures the CDI spec generator to generate a GDS spec.
-	ModeGds = "gds"
-	// ModeMofed configures the CDI spec generator to generate a MOFED spec.
-	ModeMofed = "mofed"
-	// ModeCSV configures the CDI spec generator to generate a spec based on the contents of CSV
-	// mountspec files.
-	ModeCSV = "csv"
-)
-
 // Interface defines the API for the nvcdi package
 type Interface interface {
 	GetSpec() (spec.Interface, error)

pkg/nvcdi/lib.go

@@ -46,7 +46,7 @@ type nvcdilib struct {
 	logger             logger.Interface
 	nvmllib            nvml.Interface
 	nvsandboxutilslib  nvsandboxutils.Interface
-	mode               string
+	mode               Mode
 	devicelib          device.Interface
 	deviceNamers       DeviceNamers
 	driverRoot         string
@@ -206,28 +206,6 @@ func (m *wrapper) GetCommonEdits() (*cdi.ContainerEdits, error) {
 	return edits, nil
 }
 
-// resolveMode resolves the mode for CDI spec generation based on the current system.
-func (l *nvcdilib) resolveMode() (rmode string) {
-	if l.mode != ModeAuto {
-		return l.mode
-	}
-	defer func() {
-		l.logger.Infof("Auto-detected mode as '%v'", rmode)
-	}()
-
-	platform := l.infolib.ResolvePlatform()
-	switch platform {
-	case info.PlatformNVML:
-		return ModeNvml
-	case info.PlatformTegra:
-		return ModeCSV
-	case info.PlatformWSL:
-		return ModeWsl
-	}
-	l.logger.Warningf("Unsupported platform detected: %v; assuming %v", platform, ModeNvml)
-	return ModeNvml
-}
-
 // getCudaVersion returns the CUDA version of the current system.
 func (l *nvcdilib) getCudaVersion() (string, error) {
 	version, err := l.getCudaVersionNvsandboxutils()

pkg/nvcdi/mode.go

@@ -0,0 +1,117 @@
+/**
+# Copyright 2024 NVIDIA CORPORATION
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+**/
+
+package nvcdi
+
+import (
+	"sync"
+
+	"github.com/NVIDIA/go-nvlib/pkg/nvlib/info"
+)
+
+type Mode string
+
+const (
+	// ModeAuto configures the CDI spec generator to automatically detect the system configuration
+	ModeAuto = Mode("auto")
+	// ModeNvml configures the CDI spec generator to use the NVML library.
+	ModeNvml = Mode("nvml")
+	// ModeWsl configures the CDI spec generator to generate a WSL spec.
+	ModeWsl = Mode("wsl")
+	// ModeManagement configures the CDI spec generator to generate a management spec.
+	ModeManagement = Mode("management")
+	// ModeGds configures the CDI spec generator to generate a GDS spec.
+	ModeGds = Mode("gds")
+	// ModeMofed configures the CDI spec generator to generate a MOFED spec.
+	ModeMofed = Mode("mofed")
+	// ModeCSV configures the CDI spec generator to generate a spec based on the contents of CSV
+	// mountspec files.
+	ModeCSV = Mode("csv")
+)
+
+type modeConstraint interface {
+	string | Mode
+}
+
+type modes struct {
+	lookup map[Mode]bool
+	all    []Mode
+}
+
+var validModes modes
+var validModesOnce sync.Once
+
+func getModes() modes {
+	validModesOnce.Do(func() {
+		all := []Mode{
+			ModeAuto,
+			ModeNvml,
+			ModeWsl,
+			ModeManagement,
+			ModeGds,
+			ModeMofed,
+			ModeCSV,
+		}
+		lookup := make(map[Mode]bool)
+
+		for _, m := range all {
+			lookup[m] = true
+		}
+
+		validModes = modes{
+			lookup: lookup,
+			all:    all,
+		}
+	},
+	)
+	return validModes
+}
+
+// AllModes returns the set of valid modes.
+func AllModes[T modeConstraint]() []T {
+	var output []T
+	for _, m := range getModes().all {
+		output = append(output, T(m))
+	}
+	return output
+}
+
+// IsValidMode checks whether a specified mode is valid.
+func IsValidMode[T modeConstraint](mode T) bool {
+	return getModes().lookup[Mode(mode)]
+}
+
+// resolveMode resolves the mode for CDI spec generation based on the current system.
+func (l *nvcdilib) resolveMode() (rmode Mode) {
+	if l.mode != ModeAuto {
+		return l.mode
+	}
+	defer func() {
+		l.logger.Infof("Auto-detected mode as '%v'", rmode)
+	}()
+
+	platform := l.infolib.ResolvePlatform()
+	switch platform {
+	case info.PlatformNVML:
+		return ModeNvml
+	case info.PlatformTegra:
+		return ModeCSV
+	case info.PlatformWSL:
+		return ModeWsl
+	}
+	l.logger.Warningf("Unsupported platform detected: %v; assuming %v", platform, ModeNvml)
+	return ModeNvml
+}

pkg/nvcdi/options.go

@@ -99,9 +99,9 @@ func WithNvmlLib(nvmllib nvml.Interface) Option {
 }
 
 // WithMode sets the discovery mode for the library
-func WithMode(mode string) Option {
+func WithMode[m modeConstraint](mode m) Option {
 	return func(l *nvcdilib) {
-		l.mode = mode
+		l.mode = Mode(mode)
 	}
 }