Support CDI devices as mounts

This change allows CDI devices to be requested as mounts in the
container. This enables their use in environments such as kind
where environment variables or annotations cannot be used.

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

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

@@ -174,7 +174,7 @@ func getDevicesFromEnvvar(image image.CUDA, swarmResourceEnvvars []string) *stri
 	// if specified.
 	var hasSwarmEnvvar bool
 	for _, envvar := range swarmResourceEnvvars {
-		if _, exists := image[envvar]; exists {
+		if image.HasEnvvar(envvar) {
 			hasSwarmEnvvar = true
 			break
 		}
@@ -257,28 +257,31 @@ func getDevices(hookConfig *HookConfig, image image.CUDA, mounts []Mount, privil
 	return nil
 }
 
-func getMigConfigDevices(env map[string]string) *string {
-	if devices, ok := env[envNVMigConfigDevices]; ok {
-		return &devices
-	}
-	return nil
+func getMigConfigDevices(image image.CUDA) *string {
+	return getMigDevices(image, envNVMigConfigDevices)
 }
 
-func getMigMonitorDevices(env map[string]string) *string {
-	if devices, ok := env[envNVMigMonitorDevices]; ok {
-		return &devices
-	}
-	return nil
+func getMigMonitorDevices(image image.CUDA) *string {
+	return getMigDevices(image, envNVMigMonitorDevices)
 }
 
-func (c *HookConfig) getDriverCapabilities(env map[string]string, legacyImage bool) image.DriverCapabilities {
+func getMigDevices(image image.CUDA, envvar string) *string {
+	if !image.HasEnvvar(envvar) {
+		return nil
+	}
+	devices := image.Getenv(envvar)
+	return &devices
+}
+
+func (c *HookConfig) getDriverCapabilities(cudaImage image.CUDA, legacyImage bool) image.DriverCapabilities {
 	// We use the default driver capabilities by default. This is filtered to only include the
 	// supported capabilities
 	supportedDriverCapabilities := image.NewDriverCapabilities(c.SupportedDriverCapabilities)
 
 	capabilities := supportedDriverCapabilities.Intersection(image.DefaultDriverCapabilities)
 
-	capsEnv, capsEnvSpecified := env[envNVDriverCapabilities]
+	capsEnvSpecified := cudaImage.HasEnvvar(envNVDriverCapabilities)
+	capsEnv := cudaImage.Getenv(envNVDriverCapabilities)
 
 	if !capsEnvSpecified && legacyImage {
 		// Environment variable unset with legacy image: set all capabilities.

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

@@ -465,6 +465,9 @@ func TestGetNvidiaConfig(t *testing.T) {
 	}
 	for _, tc := range tests {
 		t.Run(tc.description, func(t *testing.T) {
+			image, _ := image.New(
+				image.WithEnvMap(tc.env),
+			)
 			// Wrap the call to getNvidiaConfig() in a closure.
 			var config *nvidiaConfig
 			getConfig := func() {
@@ -473,7 +476,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 					defaultConfig, _ := getDefaultHookConfig()
 					hookConfig = &defaultConfig
 				}
-				config = getNvidiaConfig(hookConfig, tc.env, nil, tc.privileged)
+				config = getNvidiaConfig(hookConfig, image, nil, tc.privileged)
 			}
 
 			// For any tests that are expected to panic, make sure they do.
@@ -678,13 +681,17 @@ func TestDeviceListSourcePriority(t *testing.T) {
 			// Wrap the call to getDevices() in a closure.
 			var devices *string
 			getDevices := func() {
-				env := map[string]string{
-					envNVVisibleDevices: tc.envvarDevices,
-				}
+				image, _ := image.New(
+					image.WithEnvMap(
+						map[string]string{
+							envNVVisibleDevices: tc.envvarDevices,
+						},
+					),
+				)
 				hookConfig, _ := getDefaultHookConfig()
 				hookConfig.AcceptEnvvarUnprivileged = tc.acceptUnprivileged
 				hookConfig.AcceptDeviceListAsVolumeMounts = tc.acceptMounts
-				devices = getDevices(&hookConfig, env, tc.mountDevices, tc.privileged)
+				devices = getDevices(&hookConfig, image, tc.mountDevices, tc.privileged)
 			}
 
 			// For all other tests, just grab the devices and check the results
@@ -905,7 +912,10 @@ func TestGetDevicesFromEnvvar(t *testing.T) {
 
 	for i, tc := range tests {
 		t.Run(tc.description, func(t *testing.T) {
-			devices := getDevicesFromEnvvar(image.CUDA(tc.env), tc.swarmResourceEnvvars)
+			image, _ := image.New(
+				image.WithEnvMap(tc.env),
+			)
+			devices := getDevicesFromEnvvar(image, tc.swarmResourceEnvvars)
 			if tc.expectedDevices == nil {
 				require.Nil(t, devices, "%d: %v", i, tc)
 				return
@@ -1021,8 +1031,11 @@ func TestGetDriverCapabilities(t *testing.T) {
 				SupportedDriverCapabilities: tc.supportedCapabilities,
 			}
 
+			image, _ := image.New(
+				image.WithEnvMap(tc.env),
+			)
 			getDriverCapabilities := func() {
-				capabilities = c.getDriverCapabilities(tc.env, tc.legacyImage).String()
+				capabilities = c.getDriverCapabilities(image, tc.legacyImage).String()
 			}
 
 			if tc.expectedPanic {