Implement runtime package for creating runtime CLI

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

internal/runtime/api.go

@@ -0,0 +1,33 @@
+package runtime
+
+type rt struct {
+	logger       *Logger
+	modeOverride string
+}
+
+// Interface is the interface for the runtime library.
+type Interface interface {
+	Run([]string) error
+}
+
+// Option is a function that configures the runtime.
+type Option func(*rt)
+
+// New creates a runtime with the specified options.
+func New(opts ...Option) Interface {
+	r := rt{}
+	for _, opt := range opts {
+		opt(&r)
+	}
+	if r.logger == nil {
+		r.logger = NewLogger()
+	}
+	return &r
+}
+
+// WithModeOverride allows for overriding the mode specified in the config.
+func WithModeOverride(mode string) Option {
+	return func(r *rt) {
+		r.modeOverride = mode
+	}
+}

internal/runtime/logger.go

@@ -0,0 +1,240 @@
+/*
+# 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 runtime
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+)
+
+// Logger adds a way to manage output to a log file to a logrus.Logger
+type Logger struct {
+	*logrus.Logger
+	previousLogger *logrus.Logger
+	logFiles       []*os.File
+}
+
+// NewLogger creates an empty logger
+func NewLogger() *Logger {
+	return &Logger{
+		Logger: logrus.New(),
+	}
+}
+
+// Update constructs a Logger with a preddefined formatter
+func (l *Logger) Update(filename string, logLevel string, argv []string) error {
+	configFromArgs := parseArgs(argv)
+
+	level, logLevelError := configFromArgs.getLevel(logLevel)
+
+	var logFiles []*os.File
+	var argLogFileError error
+
+	// We don't create log files if the version argument is supplied
+	if !configFromArgs.version {
+		configLogFile, err := createLogFile(filename)
+		if err != nil {
+			return fmt.Errorf("error opening debug log file: %v", err)
+		}
+		if configLogFile != nil {
+			logFiles = append(logFiles, configLogFile)
+		}
+
+		argLogFile, err := createLogFile(configFromArgs.file)
+		if argLogFile != nil {
+			logFiles = append(logFiles, argLogFile)
+		}
+		argLogFileError = err
+	}
+
+	previous := l.Logger
+	l = &Logger{
+		Logger:         logrus.New(),
+		previousLogger: previous,
+		logFiles:       logFiles,
+	}
+
+	l.SetLevel(level)
+	if level == logrus.DebugLevel {
+		logrus.SetReportCaller(true)
+		// Shorten function and file names reported by the logger, by
+		// trimming common "github.com/opencontainers/runc" prefix.
+		// This is only done for text formatter.
+		_, file, _, _ := runtime.Caller(0)
+		prefix := filepath.Dir(file) + "/"
+		logrus.SetFormatter(&logrus.TextFormatter{
+			CallerPrettyfier: func(f *runtime.Frame) (string, string) {
+				function := strings.TrimPrefix(f.Function, prefix) + "()"
+				fileLine := strings.TrimPrefix(f.File, prefix) + ":" + strconv.Itoa(f.Line)
+				return function, fileLine
+			},
+		})
+	}
+
+	if configFromArgs.format == "json" {
+		l.SetFormatter(new(logrus.JSONFormatter))
+	}
+
+	if len(logFiles) == 0 {
+		l.SetOutput(io.Discard)
+	} else if len(logFiles) == 1 {
+		l.SetOutput(logFiles[0])
+	} else if len(logFiles) > 1 {
+		var writers []io.Writer
+		for _, f := range logFiles {
+			writers = append(writers, f)
+		}
+		l.SetOutput(io.MultiWriter(writers...))
+	}
+
+	if logLevelError != nil {
+		l.Warn(logLevelError)
+	}
+
+	if argLogFileError != nil {
+		l.Warnf("Failed to open log file: %v", argLogFileError)
+	}
+
+	return nil
+}
+
+// Reset closes the log file (if any) and resets the logger output to what it
+// was before UpdateLogger was called.
+func (l *Logger) Reset() error {
+	defer func() {
+		previous := l.previousLogger
+		if previous == nil {
+			previous = logrus.New()
+		}
+		l = &Logger{Logger: previous}
+	}()
+
+	var errs []error
+	for _, f := range l.logFiles {
+		err := f.Close()
+		if err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	var err error
+	for _, e := range errs {
+		if err == nil {
+			err = e
+			continue
+		}
+		return fmt.Errorf("%v; %w", e, err)
+	}
+
+	return err
+}
+
+func createLogFile(filename string) (*os.File, error) {
+	if filename != "" && filename != os.DevNull {
+		return os.OpenFile(filename, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	}
+
+	return nil, nil
+}
+
+type loggerConfig struct {
+	file    string
+	format  string
+	debug   bool
+	version bool
+}
+
+func (c loggerConfig) getLevel(logLevel string) (logrus.Level, error) {
+	if c.debug {
+		return logrus.DebugLevel, nil
+	}
+
+	if logLevel, err := logrus.ParseLevel(logLevel); err == nil {
+		return logLevel, nil
+	}
+
+	return logrus.InfoLevel, fmt.Errorf("invalid log-level '%v'", logLevel)
+}
+
+// Informed by Taken from https://github.com/opencontainers/runc/blob/7fd8b57001f5bfa102e89cb434d96bf71f7c1d35/main.go#L182
+func parseArgs(args []string) loggerConfig {
+	c := loggerConfig{}
+
+	expected := map[string]*string{
+		"log-format": &c.format,
+		"log":        &c.file,
+	}
+
+	found := make(map[string]bool)
+
+	for i := 0; i < len(args); i++ {
+		if len(found) == 4 {
+			break
+		}
+
+		param := args[i]
+
+		parts := strings.SplitN(param, "=", 2)
+		trimmed := strings.TrimLeft(parts[0], "-")
+		// If this is not a flag we continue
+		if parts[0] == trimmed {
+			continue
+		}
+
+		// Check the version flag
+		if trimmed == "version" {
+			c.version = true
+			found["version"] = true
+			// For the version flag we don't process any other flags
+			continue
+		}
+
+		// Check the debug flag
+		if trimmed == "debug" {
+			c.debug = true
+			found["debug"] = true
+			continue
+		}
+
+		destination, exists := expected[trimmed]
+		if !exists {
+			continue
+		}
+
+		var value string
+		if len(parts) == 2 {
+			value = parts[2]
+		} else if i+1 < len(args) {
+			value = args[i+1]
+			i++
+		} else {
+			continue
+		}
+
+		*destination = value
+		found[trimmed] = true
+	}
+
+	return c
+}

internal/runtime/runtime.go

@@ -0,0 +1,101 @@
+/**
+# Copyright (c) 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 runtime
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/info"
+	"github.com/opencontainers/runtime-spec/specs-go"
+)
+
+// Run is an entry point that allows for idiomatic handling of errors
+// when calling from the main function.
+func (r rt) Run(argv []string) (rerr error) {
+	defer func() {
+		if rerr != nil {
+			r.logger.Errorf("%v", rerr)
+		}
+	}()
+
+	printVersion := hasVersionFlag(argv)
+	if printVersion {
+		fmt.Printf("%v version %v\n", "NVIDIA Container Runtime", info.GetVersionString(fmt.Sprintf("spec: %v", specs.Version)))
+	}
+
+	cfg, err := config.GetConfig()
+	if err != nil {
+		return fmt.Errorf("error loading config: %v", err)
+	}
+	if r.modeOverride != "" {
+		cfg.NVIDIAContainerRuntimeConfig.Mode = r.modeOverride
+	}
+
+	err = r.logger.Update(
+		cfg.NVIDIAContainerRuntimeConfig.DebugFilePath,
+		cfg.NVIDIAContainerRuntimeConfig.LogLevel,
+		argv,
+	)
+	if err != nil {
+		return fmt.Errorf("failed to set up logger: %v", err)
+	}
+	defer func() {
+		if rerr != nil {
+			r.logger.Errorf("%v", rerr)
+		}
+		r.logger.Reset()
+	}()
+
+	r.logger.Infof("Using config %+v", cfg)
+	r.logger.Debugf("Command line arguments: %v", argv)
+	runtime, err := newNVIDIAContainerRuntime(r.logger.Logger, cfg, argv)
+	if err != nil {
+		return fmt.Errorf("failed to create NVIDIA Container Runtime: %v", err)
+	}
+
+	if printVersion {
+		fmt.Print("\n")
+	}
+	return runtime.Exec(argv)
+}
+
+func (r rt) Errorf(format string, args ...interface{}) {
+	r.logger.Errorf(format, args...)
+}
+
+// TODO: This should be refactored / combined with parseArgs in logger.
+func hasVersionFlag(args []string) bool {
+	for i := 0; i < len(args); i++ {
+		param := args[i]
+
+		parts := strings.SplitN(param, "=", 2)
+		trimmed := strings.TrimLeft(parts[0], "-")
+		// If this is not a flag we continue
+		if parts[0] == trimmed {
+			continue
+		}
+
+		// Check the version flag
+		if trimmed == "version" {
+			return true
+		}
+	}
+
+	return false
+}

internal/runtime/runtime_factory.go

@@ -0,0 +1,110 @@
+/*
+# 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 runtime
+
+import (
+	"fmt"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/info"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/modifier"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/oci"
+	"github.com/sirupsen/logrus"
+)
+
+// newNVIDIAContainerRuntime is a factory method that constructs a runtime based on the selected configuration and specified logger
+func newNVIDIAContainerRuntime(logger *logrus.Logger, cfg *config.Config, argv []string) (oci.Runtime, error) {
+	lowLevelRuntime, err := oci.NewLowLevelRuntime(logger, cfg.NVIDIAContainerRuntimeConfig.Runtimes)
+	if err != nil {
+		return nil, fmt.Errorf("error constructing low-level runtime: %v", err)
+	}
+
+	if !oci.HasCreateSubcommand(argv) {
+		logger.Debugf("Skipping modifier for non-create subcommand")
+		return lowLevelRuntime, nil
+	}
+
+	ociSpec, err := oci.NewSpec(logger, argv)
+	if err != nil {
+		return nil, fmt.Errorf("error constructing OCI specification: %v", err)
+	}
+
+	specModifier, err := newSpecModifier(logger, cfg, ociSpec, argv)
+	if err != nil {
+		return nil, fmt.Errorf("failed to construct OCI spec modifier: %v", err)
+	}
+
+	// Create the wrapping runtime with the specified modifier
+	r := oci.NewModifyingRuntimeWrapper(
+		logger,
+		lowLevelRuntime,
+		ociSpec,
+		specModifier,
+	)
+
+	return r, nil
+}
+
+// newSpecModifier is a factory method that creates constructs an OCI spec modifer based on the provided config.
+func newSpecModifier(logger *logrus.Logger, cfg *config.Config, ociSpec oci.Spec, argv []string) (oci.SpecModifier, error) {
+	modeModifier, err := newModeModifier(logger, cfg, ociSpec, argv)
+	if err != nil {
+		return nil, err
+	}
+
+	graphicsModifier, err := modifier.NewGraphicsModifier(logger, cfg, ociSpec)
+	if err != nil {
+		return nil, err
+	}
+
+	gdsModifier, err := modifier.NewGDSModifier(logger, cfg, ociSpec)
+	if err != nil {
+		return nil, err
+	}
+
+	mofedModifier, err := modifier.NewMOFEDModifier(logger, cfg, ociSpec)
+	if err != nil {
+		return nil, err
+	}
+
+	tegraModifier, err := modifier.NewTegraPlatformFiles(logger)
+	if err != nil {
+		return nil, err
+	}
+
+	modifiers := modifier.Merge(
+		modeModifier,
+		graphicsModifier,
+		gdsModifier,
+		mofedModifier,
+		tegraModifier,
+	)
+	return modifiers, nil
+}
+
+func newModeModifier(logger *logrus.Logger, cfg *config.Config, ociSpec oci.Spec, argv []string) (oci.SpecModifier, error) {
+	switch info.ResolveAutoMode(logger, cfg.NVIDIAContainerRuntimeConfig.Mode) {
+	case "legacy":
+		return modifier.NewStableRuntimeModifier(logger), nil
+	case "csv":
+		return modifier.NewCSVModifier(logger, cfg, ociSpec)
+	case "cdi":
+		return modifier.NewCDIModifier(logger, cfg, ociSpec)
+	}
+
+	return nil, fmt.Errorf("invalid runtime mode: %v", cfg.NVIDIAContainerRuntimeConfig.Mode)
+}

internal/runtime/runtime_factory_test.go

@@ -0,0 +1,161 @@
+/*
+# 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 runtime
+
+import (
+	"encoding/json"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/test"
+	"github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/sirupsen/logrus"
+	testlog "github.com/sirupsen/logrus/hooks/test"
+	"github.com/stretchr/testify/require"
+)
+
+const (
+	runcExecutableName = "runc"
+)
+
+func TestMain(m *testing.M) {
+	// TEST SETUP
+	// Determine the module root and the test binary path
+	var err error
+	moduleRoot, err := test.GetModuleRoot()
+	if err != nil {
+		logrus.Fatalf("error in test setup: could not get module root: %v", err)
+	}
+	testBinPath := filepath.Join(moduleRoot, "test", "bin")
+
+	// Set the environment variables for the test
+	os.Setenv("PATH", test.PrependToPath(testBinPath, moduleRoot))
+
+	// Confirm that the environment is configured correctly
+	runcPath, err := exec.LookPath(runcExecutableName)
+	if err != nil || filepath.Join(testBinPath, runcExecutableName) != runcPath {
+		logrus.Fatalf("error in test setup: mock runc path set incorrectly in TestMain(): %v", err)
+	}
+
+	// RUN TESTS
+	exitCode := m.Run()
+
+	os.Exit(exitCode)
+}
+
+func TestFactoryMethod(t *testing.T) {
+	logger, _ := testlog.NewNullLogger()
+
+	testCases := []struct {
+		description   string
+		cfg           *config.Config
+		spec          *specs.Spec
+		expectedError bool
+	}{
+		{
+			description: "empty config raises error",
+			cfg: &config.Config{
+				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{},
+			},
+			expectedError: true,
+		},
+		{
+			description: "config with runtime raises no error",
+			cfg: &config.Config{
+				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
+					Runtimes: []string{"runc"},
+					Mode:     "legacy",
+				},
+			},
+		},
+		{
+			description: "csv mode is supported",
+			cfg: &config.Config{
+				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
+					Runtimes: []string{"runc"},
+					Mode:     "csv",
+				},
+			},
+			spec: &specs.Spec{
+				Process: &specs.Process{
+					Env: []string{
+						"NVIDIA_VISIBLE_DEVICES=all",
+					},
+				},
+			},
+		},
+		{
+			description: "non-legacy discover mode raises error",
+			cfg: &config.Config{
+				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
+					Runtimes: []string{"runc"},
+					Mode:     "non-legacy",
+				},
+			},
+			expectedError: true,
+		},
+		{
+			description: "legacy discover mode returns modifier",
+			cfg: &config.Config{
+				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
+					Runtimes: []string{"runc"},
+					Mode:     "legacy",
+				},
+			},
+		},
+		{
+			description: "csv discover mode returns modifier",
+			cfg: &config.Config{
+				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
+					Runtimes: []string{"runc"},
+					Mode:     "csv",
+				},
+			},
+		},
+		{
+			description: "empty mode raises error",
+			cfg: &config.Config{
+				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
+					Runtimes: []string{"runc"},
+				},
+			},
+			expectedError: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			bundleDir := t.TempDir()
+
+			specFile, err := os.Create(filepath.Join(bundleDir, "config.json"))
+			require.NoError(t, err)
+			require.NoError(t, json.NewEncoder(specFile).Encode(tc.spec))
+
+			argv := []string{"--bundle", bundleDir, "create"}
+
+			_, err = newNVIDIAContainerRuntime(logger, tc.cfg, argv)
+			if tc.expectedError {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}