Add code to process Jetpack CSV files

This change adds code to process Jetpack CSV mount specifications.

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

internal/discover/csv/csv.go

@@ -0,0 +1,90 @@
+/**
+# Copyright (c) 2021, 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 csv
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	// DefaultRoot is default location of CSV files that define the modifications required to the OCI spec
+	DefaultRoot = "/etc/nvidia-container-runtime/host-files-for-container.d"
+)
+
+// GetFileList returns the (non-recursive) list of CSV files in the specified
+// folder
+func GetFileList(root string) ([]string, error) {
+	contents, err := os.ReadDir(root)
+	if err != nil && errors.Is(err, os.ErrNotExist) {
+		return nil, nil
+	} else if err != nil {
+		return nil, fmt.Errorf("failed to read the contents of %v: %v", root, err)
+	}
+
+	var csvFilePaths []string
+	for _, c := range contents {
+		if c.IsDir() {
+			continue
+		}
+		if c.Name() == ".csv" {
+			continue
+		}
+		ext := strings.ToLower(filepath.Ext(c.Name()))
+		if ext != ".csv" {
+			continue
+		}
+
+		csvFilePaths = append(csvFilePaths, filepath.Join(root, c.Name()))
+	}
+
+	return csvFilePaths, nil
+}
+
+// ParseFile parses the specified file and returns a list of required jetson mounts
+func ParseFile(logger *logrus.Logger, filename string) ([]*MountSpec, error) {
+	csvFile, err := os.Open(filename)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open %v for reading: %v", filename, err)
+	}
+	return parseCSVFromReader(logger, csvFile), nil
+}
+
+// parseCSVFromReader parses the specified file and returns a list of required jetson mounts
+func parseCSVFromReader(logger *logrus.Logger, reader io.Reader) []*MountSpec {
+	var targets []*MountSpec
+
+	scanner := bufio.NewScanner(reader)
+	for scanner.Scan() {
+		line := scanner.Text()
+		target, err := NewMountSpecFromLine(line)
+		if err != nil {
+			logger.Debugf("Skipping invalid mount spec '%v': %v", line, err)
+			continue
+		}
+		targets = append(targets, target)
+	}
+
+	return targets
+}

internal/discover/csv/csv_test.go

@@ -0,0 +1,83 @@
+/**
+# Copyright (c) 2021, 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 csv
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetFileList(t *testing.T) {
+	moduleRoot, _ := test.GetModuleRoot()
+
+	testCases := []struct {
+		description   string
+		root          string
+		files         []string
+		expectedError error
+	}{
+		{
+			description: "returns list of CSV files",
+			root:        "test/input/csv_samples/",
+			files: []string{
+				"jetson.csv",
+				"simple_wrong.csv",
+				"simple.csv",
+				"spaced.csv",
+			},
+		},
+		{
+			description: "handles empty folder",
+			root:        "test/input/csv_samples/empty",
+		},
+		{
+			description: "handles non-existent folder",
+			root:        "test/input/csv_samples/NONEXISTENT",
+		},
+		{
+			description: "handles non-existent folder root",
+			root:        "/NONEXISTENT/test/input/csv_samples/",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			root := filepath.Join(moduleRoot, tc.root)
+			files, err := GetFileList(root)
+
+			if tc.expectedError != nil {
+				require.Error(t, err)
+				require.Empty(t, files)
+				return
+			}
+
+			require.NoError(t, err)
+
+			var foundFiles []string
+			for _, f := range files {
+				require.Equal(t, root, filepath.Dir(f))
+				require.Equal(t, ".csv", filepath.Ext(f))
+				foundFiles = append(foundFiles, filepath.Base(f))
+			}
+
+			require.ElementsMatch(t, tc.files, foundFiles)
+		})
+	}
+}

internal/discover/csv/mount_spec.go

@@ -0,0 +1,73 @@
+/**
+# Copyright (c) 2021-2022, 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 csv
+
+import (
+	"fmt"
+	"strings"
+)
+
+// MountSpecType defines the mount types allowed in a CSV file
+type MountSpecType string
+
+const (
+	// MountSpecDev is used for character devices
+	MountSpecDev = MountSpecType("dev")
+	// MountSpecDir is used for directories
+	MountSpecDir = MountSpecType("dir")
+	// MountSpecLib is used for libraries or regular files
+	MountSpecLib = MountSpecType("lib")
+	// MountSpecSym is used for symlinks.
+	MountSpecSym = MountSpecType("sym")
+)
+
+// MountSpec represents a Jetson mount consisting of a type and a path.
+type MountSpec struct {
+	Type MountSpecType
+	Path string
+}
+
+// NewMountSpecFromLine parses the specified line and returns the MountSpec or an error if the line is malformed
+func NewMountSpecFromLine(line string) (*MountSpec, error) {
+	parts := strings.SplitN(strings.TrimSpace(line), ",", 2)
+	if len(parts) < 2 {
+		return nil, fmt.Errorf("failed to parse line: %v", line)
+	}
+	mountType := strings.TrimSpace(parts[0])
+	path := strings.TrimSpace(parts[1])
+
+	return NewMountSpec(mountType, path)
+}
+
+// NewMountSpec creates a MountSpec with the specified type and path. An error is returned if the type is invalid.
+func NewMountSpec(mountType string, path string) (*MountSpec, error) {
+	switch mountType {
+	case "dev", "lib", "sym", "dir":
+	default:
+		return nil, fmt.Errorf("unexpected mount type: %v", mountType)
+	}
+	if path == "" {
+		return nil, fmt.Errorf("invalid path: %v", path)
+	}
+
+	mount := MountSpec{
+		Type: MountSpecType(mountType),
+		Path: path,
+	}
+
+	return &mount, nil
+}

internal/discover/csv/mount_spec_test.go

@@ -0,0 +1,82 @@
+/**
+# Copyright (c) 2022, 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 csv
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewMountSpecFromLine(t *testing.T) {
+	parseError := fmt.Errorf("failed to parse line")
+	unexpectedError := fmt.Errorf("unexpected mount type")
+
+	testCases := []struct {
+		line          string
+		expectedError error
+		expectedValue MountSpec
+	}{
+		{
+			line:          "",
+			expectedError: parseError,
+		},
+		{
+			line:          "\t",
+			expectedError: parseError,
+		},
+		{
+			line:          ",",
+			expectedError: parseError,
+		},
+		{
+			line:          "dev,",
+			expectedError: parseError,
+		},
+		{
+			line: "dev ,/a/path",
+			expectedValue: MountSpec{
+				Path: "/a/path",
+				Type: "dev",
+			},
+		},
+		{
+			line: "dev ,/a/path,with,commas",
+			expectedValue: MountSpec{
+				Path: "/a/path,with,commas",
+				Type: "dev",
+			},
+		},
+		{
+			line:          "not-dev ,/a/path",
+			expectedError: unexpectedError,
+		},
+	}
+
+	for i, tc := range testCases {
+		t.Run(fmt.Sprintf("test case %d", i), func(t *testing.T) {
+			target, err := NewMountSpecFromLine(tc.line)
+			if tc.expectedError != nil {
+				require.Error(t, err)
+				return
+			}
+			require.NoError(t, err)
+			require.EqualValues(t, &tc.expectedValue, target)
+		})
+	}
+}