Move runtime config to internal package

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

cmd/nvidia-container-runtime/main.go

@@ -3,18 +3,8 @@ package main
 import (
 	"fmt"
 	"os"
-	"path"
 
-	"github.com/pelletier/go-toml"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
-)
-
-const (
-	configOverride = "XDG_CONFIG_HOME"
-	configFilePath = "nvidia-container-runtime/config.toml"
-)
-
-var (
-	configDir = "/etc/"
 )
 
 var logger = NewLogger()
@@ -30,12 +20,12 @@ func main() {
 // run is an entry point that allows for idiomatic handling of errors
 // when calling from the main function.
 func run(argv []string) (rerr error) {
-	cfg, err := getConfig()
+	cfg, err := config.GetRuntimeConfig()
 	if err != nil {
 		return fmt.Errorf("error loading config: %v", err)
 	}
 
-	err = logger.LogToFile(cfg.debugFilePath)
+	err = logger.LogToFile(cfg.DebugFilePath)
 	if err != nil {
 		return fmt.Errorf("error opening debug log file: %v", err)
 	}
@@ -54,35 +44,3 @@ func run(argv []string) (rerr error) {
 
 	return runtime.Exec(argv)
 }
-
-type config struct {
-	debugFilePath string
-	Experimental  bool
-}
-
-// getConfig sets up the config struct. Values are read from a toml file
-// or set via the environment.
-func getConfig() (*config, error) {
-	cfg := &config{}
-
-	if XDGConfigDir := os.Getenv(configOverride); len(XDGConfigDir) != 0 {
-		configDir = XDGConfigDir
-	}
-
-	configFilePath := path.Join(configDir, configFilePath)
-
-	tomlContent, err := os.ReadFile(configFilePath)
-	if err != nil {
-		return nil, err
-	}
-
-	toml, err := toml.Load(string(tomlContent))
-	if err != nil {
-		return nil, err
-	}
-
-	cfg.debugFilePath = toml.GetDefault("nvidia-container-runtime.debug", "/dev/null").(string)
-	cfg.Experimental = toml.GetDefault("nvidia-container-runtime.experimental", false).(bool)
-
-	return cfg, nil
-}

cmd/nvidia-container-runtime/main_test.go

@@ -245,24 +245,3 @@ func nvidiaHookCount(hooks *specs.Hooks) int {
 	}
 	return count
 }
-
-func TestGetConfigWithCustomConfig(t *testing.T) {
-	wd, err := os.Getwd()
-	require.NoError(t, err)
-
-	// By default debug is disabled
-	contents := []byte("[nvidia-container-runtime]\ndebug = \"/nvidia-container-toolkit.log\"")
-	testDir := filepath.Join(wd, "test")
-	filename := filepath.Join(testDir, configFilePath)
-
-	os.Setenv(configOverride, testDir)
-
-	require.NoError(t, os.MkdirAll(filepath.Dir(filename), 0766))
-	require.NoError(t, ioutil.WriteFile(filename, contents, 0766))
-
-	defer func() { require.NoError(t, os.RemoveAll(testDir)) }()
-
-	cfg, err := getConfig()
-	require.NoError(t, err)
-	require.Equal(t, cfg.debugFilePath, "/nvidia-container-toolkit.log")
-}

cmd/nvidia-container-runtime/runtime_factory.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 
 	"github.com/NVIDIA/nvidia-container-toolkit/cmd/nvidia-container-runtime/modifier"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/oci"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/runtime"
 	"github.com/sirupsen/logrus"
@@ -31,7 +32,7 @@ const (
 )
 
 // newNVIDIAContainerRuntime is a factory method that constructs a runtime based on the selected configuration and specified logger
-func newNVIDIAContainerRuntime(logger *logrus.Logger, cfg *config, argv []string) (oci.Runtime, error) {
+func newNVIDIAContainerRuntime(logger *logrus.Logger, cfg *config.RuntimeConfig, argv []string) (oci.Runtime, error) {
 	ociSpec, err := oci.NewSpec(logger, argv)
 	if err != nil {
 		return nil, fmt.Errorf("error constructing OCI specification: %v", err)

cmd/nvidia-container-runtime/runtime_factory_test.go

@@ -19,6 +19,7 @@ package main
 import (
 	"testing"
 
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
 	testlog "github.com/sirupsen/logrus/hooks/test"
 	"github.com/stretchr/testify/require"
 )
@@ -28,13 +29,13 @@ func TestFactoryMethod(t *testing.T) {
 
 	testCases := []struct {
 		description   string
-		config        config
+		config        config.RuntimeConfig
 		argv          []string
 		expectedError bool
 	}{
 		{
 			description: "empty config no error",
-			config:      config{},
+			config:      config.RuntimeConfig{},
 		},
 	}
 

internal/config/runtime.go

@@ -0,0 +1,89 @@
+/**
+# 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 config
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path"
+
+	"github.com/pelletier/go-toml"
+)
+
+const (
+	configOverride = "XDG_CONFIG_HOME"
+	configFilePath = "nvidia-container-runtime/config.toml"
+)
+
+var (
+	configDir = "/etc/"
+)
+
+// RuntimeConfig stores the config options for the NVIDIA Container Runtime
+type RuntimeConfig struct {
+	DebugFilePath string
+	Experimental  bool
+}
+
+// GetRuntimeConfig sets up the config struct. Values are read from a toml file
+// or set via the environment.
+func GetRuntimeConfig() (*RuntimeConfig, error) {
+	if XDGConfigDir := os.Getenv(configOverride); len(XDGConfigDir) != 0 {
+		configDir = XDGConfigDir
+	}
+
+	configFilePath := path.Join(configDir, configFilePath)
+
+	tomlFile, err := os.Open(configFilePath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open config file %v: %v", configFilePath, err)
+	}
+	defer tomlFile.Close()
+
+	cfg, err := getRuntimeConfigFrom(tomlFile)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read config values: %v", err)
+	}
+
+	return cfg, nil
+}
+
+// getRuntimeConfigFrom reads the config from the specified Reader
+func getRuntimeConfigFrom(reader io.Reader) (*RuntimeConfig, error) {
+	toml, err := toml.LoadReader(reader)
+	if err != nil {
+		return nil, err
+	}
+
+	cfg := getDefaultRuntimeConfig()
+
+	cfg.DebugFilePath = toml.GetDefault("nvidia-container-runtime.debug", cfg.DebugFilePath).(string)
+	cfg.Experimental = toml.GetDefault("nvidia-container-runtime.experimental", cfg.Experimental).(bool)
+
+	return cfg, nil
+}
+
+// getDefaultRuntimeConfig defines the default values for the config
+func getDefaultRuntimeConfig() *RuntimeConfig {
+	c := RuntimeConfig{
+		DebugFilePath: "/dev/null",
+		Experimental:  false,
+	}
+
+	return &c
+}

internal/config/runtime_test.go

@@ -0,0 +1,98 @@
+/**
+# 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 config
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGerRuntimeConfigWithCustomConfig(t *testing.T) {
+	wd, err := os.Getwd()
+	require.NoError(t, err)
+
+	// By default debug is disabled
+	contents := []byte("[nvidia-container-runtime]\ndebug = \"/nvidia-container-toolkit.log\"")
+	testDir := filepath.Join(wd, "test")
+	filename := filepath.Join(testDir, configFilePath)
+
+	os.Setenv(configOverride, testDir)
+
+	require.NoError(t, os.MkdirAll(filepath.Dir(filename), 0766))
+	require.NoError(t, ioutil.WriteFile(filename, contents, 0766))
+
+	defer func() { require.NoError(t, os.RemoveAll(testDir)) }()
+
+	cfg, err := GetRuntimeConfig()
+	require.NoError(t, err)
+	require.Equal(t, cfg.DebugFilePath, "/nvidia-container-toolkit.log")
+}
+
+func TestGerRuntimeConfig(t *testing.T) {
+	testCases := []struct {
+		description    string
+		contents       []string
+		expectedError  error
+		expectedConfig *RuntimeConfig
+	}{
+		{
+			description: "empty config is default",
+			expectedConfig: &RuntimeConfig{
+				DebugFilePath: "/dev/null",
+			},
+		},
+		{
+			description: "config options set inline",
+			contents: []string{
+				"nvidia-container-runtime.debug = \"/foo/bar\"",
+			},
+			expectedConfig: &RuntimeConfig{
+				DebugFilePath: "/foo/bar",
+			},
+		},
+		{
+			description: "config options set in section",
+			contents: []string{
+				"[nvidia-container-runtime]",
+				"debug = \"/foo/bar\"",
+			},
+			expectedConfig: &RuntimeConfig{
+				DebugFilePath: "/foo/bar",
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			reader := strings.NewReader(strings.Join(tc.contents, "\n"))
+
+			cfg, err := getRuntimeConfigFrom(reader)
+			if tc.expectedError != nil {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+			}
+
+			require.EqualValues(t, tc.expectedConfig, cfg)
+		})
+	}
+}