[no-relnote] Add test for libcuda lookup

This change adds a test for locating libcuda as a driver library.
This includes a failing test on a system where libcuda.so.1 is in
the ldcache, but not at one of the predefined library search paths.

A testdata folder with sample root filesystems is included to test
various combinations.

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

internal/lookup/root/root_test.go

@@ -0,0 +1,81 @@
+/**
+# Copyright 2023 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 root
+
+import (
+	"path/filepath"
+	"testing"
+
+	testlog "github.com/sirupsen/logrus/hooks/test"
+	"github.com/stretchr/testify/require"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/lookup"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/test"
+)
+
+func TestDriverLibrariesLocate(t *testing.T) {
+	logger, _ := testlog.NewNullLogger()
+
+	moduleRoot, err := test.GetModuleRoot()
+	require.NoError(t, err)
+
+	testCases := []struct {
+		rootFs        string
+		inputs        []string
+		expected      string
+		expectedError error
+	}{
+		{
+			rootFs:        "rootfs-empty",
+			inputs:        []string{"libcuda.so.1", "libcuda.so.*", "libcuda.so.*.*", "libcuda.so.999.88.77"},
+			expectedError: lookup.ErrNotFound,
+		},
+		{
+			rootFs:   "rootfs-no-cache-lib64",
+			inputs:   []string{"libcuda.so.1", "libcuda.so.*", "libcuda.so.*.*", "libcuda.so.999.88.77"},
+			expected: "/usr/lib64/libcuda.so.999.88.77",
+		},
+		{
+			rootFs:   "rootfs-1",
+			inputs:   []string{"libcuda.so.1", "libcuda.so.*", "libcuda.so.*.*", "libcuda.so.999.88.77"},
+			expected: "/lib/x86_64-linux-gnu/libcuda.so.999.88.77",
+		},
+		{
+			rootFs:   "rootfs-2",
+			inputs:   []string{"libcuda.so.1", "libcuda.so.*", "libcuda.so.*.*", "libcuda.so.999.88.77"},
+			expected: "/var/lib/nvidia/lib64/libcuda.so.999.88.77",
+		},
+	}
+
+	for _, tc := range testCases {
+		for _, input := range tc.inputs {
+			t.Run(tc.rootFs+input, func(t *testing.T) {
+				rootfs := filepath.Join(moduleRoot, "testdata", "lookup", tc.rootFs)
+				driver := New(
+					WithLogger(logger),
+					WithDriverRoot(rootfs),
+				)
+
+				candidates, err := driver.Libraries().Locate(input)
+				require.ErrorIs(t, err, tc.expectedError)
+				if tc.expectedError == nil {
+					require.Equal(t, []string{filepath.Join(rootfs, tc.expected)}, candidates)
+				}
+			})
+		}
+	}
+}

testdata/lookup/rootfs-1/README.md

@@ -0,0 +1,2 @@
+This rootfs represents a host with the CUDA driver libraries installed in
+/lib/x86_64-linux-gnu. The included /etc/ld.so.cache was copied from such as system.

testdata/lookup/rootfs-1/lib/x86_64-linux-gnu/libcuda.so.1

@@ -0,0 +1 @@
+libcuda.so.999.88.77

testdata/lookup/rootfs-2/README.md

@@ -0,0 +1,3 @@
+This rootfs represents a host with the CUDA driver libraries installed in
+/var/lib/nvidia/lib64. The included /etc/ld.so.cache was generated in a container
+simulating such as system.

testdata/lookup/rootfs-2/var/lib/nvidia/lib64/libcuda.so.1

@@ -0,0 +1 @@
+libcuda.so.999.88.77

testdata/lookup/rootfs-empty/README.md

@@ -0,0 +1 @@
+The folders represents an empty rootfs.

testdata/lookup/rootfs-no-cache-lib64/usr/lib64/libcuda.so.1

@@ -0,0 +1 @@
+libcuda.so.999.88.77