[no-relnote] Add basic CDI generate test

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

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

@@ -25,6 +25,8 @@ import (
 	"github.com/urfave/cli/v2"
 	cdi "tags.cncf.io/container-device-interface/pkg/parser"
 
+	"github.com/NVIDIA/go-nvml/pkg/nvml"
+
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/logger"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/platform-support/tegra/csv"
@@ -60,6 +62,9 @@ type options struct {
 		files          cli.StringSlice
 		ignorePatterns cli.StringSlice
 	}
+
+	// the following are used for dependency injection during spec generation.
+	nvmllib nvml.Interface
 }
 
 // NewCommand constructs a generate-cdi command with the specified logger
@@ -269,6 +274,8 @@ func (m command) generateSpec(opts *options) (spec.Interface, error) {
 		nvcdi.WithLibrarySearchPaths(opts.librarySearchPaths.Value()),
 		nvcdi.WithCSVFiles(opts.csv.files.Value()),
 		nvcdi.WithCSVIgnorePatterns(opts.csv.ignorePatterns.Value()),
+		// We set the following to allow for dependency injection:
+		nvcdi.WithNvmlLib(opts.nvmllib),
 	)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create CDI library: %v", err)

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

@@ -0,0 +1,151 @@
+/**
+# Copyright (c) 2025, NVIDIA CORPORATION.  All rights reserved.
+#
+# 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 generate
+
+import (
+	"bytes"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/NVIDIA/go-nvml/pkg/nvml"
+	"github.com/NVIDIA/go-nvml/pkg/nvml/mock/dgxa100"
+	testlog "github.com/sirupsen/logrus/hooks/test"
+	"github.com/stretchr/testify/require"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/test"
+)
+
+func TestGenerateSpec(t *testing.T) {
+	t.Setenv("__NVCT_TESTING_DEVICES_ARE_FILES", "true")
+	moduleRoot, err := test.GetModuleRoot()
+	require.NoError(t, err)
+
+	driverRoot := filepath.Join(moduleRoot, "testdata", "lookup", "rootfs-1")
+
+	logger, _ := testlog.NewNullLogger()
+	testCases := []struct {
+		description           string
+		options               options
+		expectedValidateError error
+		expectedOptions       options
+		expectedError         error
+		expectedSpec          string
+	}{
+		{
+			description: "default",
+			options: options{
+				format:     "yaml",
+				mode:       "nvml",
+				vendor:     "example.com",
+				class:      "device",
+				driverRoot: driverRoot,
+			},
+			expectedOptions: options{
+				format:            "yaml",
+				mode:              "nvml",
+				vendor:            "example.com",
+				class:             "device",
+				nvidiaCDIHookPath: "/usr/bin/nvidia-cdi-hook",
+				driverRoot:        driverRoot,
+			},
+			expectedSpec: `---
+cdiVersion: 0.5.0
+containerEdits:
+  deviceNodes:
+  - hostPath: {{ .driverRoot }}/dev/nvidiactl
+    path: /dev/nvidiactl
+  env:
+  - NVIDIA_VISIBLE_DEVICES=void
+  hooks:
+  - args:
+    - nvidia-cdi-hook
+    - create-symlinks
+    - --link
+    - libcuda.so.1::/lib/x86_64-linux-gnu/libcuda.so
+    hookName: createContainer
+    path: /usr/bin/nvidia-cdi-hook
+  - args:
+    - nvidia-cdi-hook
+    - update-ldcache
+    - --folder
+    - /lib/x86_64-linux-gnu
+    hookName: createContainer
+    path: /usr/bin/nvidia-cdi-hook
+  mounts:
+  - containerPath: /lib/x86_64-linux-gnu/libcuda.so.999.88.77
+    hostPath: {{ .driverRoot }}/lib/x86_64-linux-gnu/libcuda.so.999.88.77
+    options:
+    - ro
+    - nosuid
+    - nodev
+    - bind
+devices:
+- containerEdits:
+    deviceNodes:
+    - hostPath: {{ .driverRoot }}/dev/nvidia0
+      path: /dev/nvidia0
+  name: "0"
+- containerEdits:
+    deviceNodes:
+    - hostPath: {{ .driverRoot }}/dev/nvidia0
+      path: /dev/nvidia0
+  name: all
+kind: example.com/device
+`,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			c := command{
+				logger: logger,
+			}
+
+			err := c.validateFlags(nil, &tc.options)
+			require.ErrorIs(t, err, tc.expectedValidateError)
+			require.EqualValues(t, tc.expectedOptions, tc.options)
+
+			// Set up a mock server, reusing the DGX A100 mock.
+			server := dgxa100.New()
+			// Override the driver version to match the version in our mock filesystem.
+			server.SystemGetDriverVersionFunc = func() (string, nvml.Return) {
+				return "999.88.77", nvml.SUCCESS
+			}
+			// Set the device count to 1 explicitly since we only have a single device node.
+			server.DeviceGetCountFunc = func() (int, nvml.Return) {
+				return 1, nvml.SUCCESS
+			}
+			for _, d := range server.Devices {
+				// TODO: This is not implemented in the mock.
+				(d.(*dgxa100.Device)).GetMaxMigDeviceCountFunc = func() (int, nvml.Return) {
+					return 0, nvml.SUCCESS
+				}
+			}
+			tc.options.nvmllib = server
+
+			spec, err := c.generateSpec(&tc.options)
+			require.ErrorIs(t, err, tc.expectedError)
+
+			var buf bytes.Buffer
+			_, err = spec.WriteTo(&buf)
+			require.NoError(t, err)
+
+			require.Equal(t, strings.ReplaceAll(tc.expectedSpec, "{{ .driverRoot }}", driverRoot), buf.String())
+		})
+	}
+}