Add nvidia-container-runtime.runtimes config option

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

cmd/nvidia-container-runtime/main_test.go

@@ -24,6 +24,10 @@ const (
 	unmodifiedSpecFileSuffix = "test/input/test_spec.json"
 )
 
+const (
+	runcExecutableName = "runc"
+)
+
 type testConfig struct {
 	root    string
 	binPath string

cmd/nvidia-container-runtime/runtime_factory.go

@@ -26,15 +26,9 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-const (
-	dockerRuncExecutableName = "docker-runc"
-	runcExecutableName       = "runc"
-)
-
 // 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) {
-	lowLevelRuntimeCandidates := []string{dockerRuncExecutableName, runcExecutableName}
-	lowLevelRuntime, err := oci.NewLowLevelRuntime(logger, lowLevelRuntimeCandidates)
+	lowLevelRuntime, err := oci.NewLowLevelRuntime(logger, cfg.NVIDIAContainerRuntimeConfig.Runtimes)
 	if err != nil {
 		return nil, fmt.Errorf("error constructing low-level runtime: %v", err)
 	}

cmd/nvidia-container-runtime/runtime_factory_test.go

@@ -38,10 +38,19 @@ func TestFactoryMethod(t *testing.T) {
 		expectedError bool
 	}{
 		{
-			description: "empty config no error",
+			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"},
+				},
+			},
 		},
 		{
 			description: "experimental flag supported",
@@ -49,6 +58,7 @@ func TestFactoryMethod(t *testing.T) {
 				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
 					Experimental: true,
 					DiscoverMode: "legacy",
+					Runtimes:     []string{"runc"},
 				},
 			},
 			spec: &specs.Spec{

config/config.toml.ubuntu

@@ -17,3 +17,10 @@ ldconfig = "@/sbin/ldconfig.real"
 [nvidia-container-runtime]
 #debug = "/var/log/nvidia-container-runtime.log"
 #experimental = false
+
+# Specify the runtimes to consider. This list is processed in order and the PATH
+# searched for matching executables unless the entry is an absolute path.
+runtimes = [
+    "docker-runc",
+    "runc",
+]

internal/config/config_test.go

@@ -65,6 +65,7 @@ func TestGetConfig(t *testing.T) {
 					Experimental:  false,
 					DiscoverMode:  "auto",
 					LogLevel:      "info",
+					Runtimes:      []string{"docker-runc", "runc"},
 				},
 				NVIDIACTKConfig: CTKConfig{
 					Path: "nvidia-ctk",
@@ -79,6 +80,7 @@ func TestGetConfig(t *testing.T) {
 				"nvidia-container-runtime.experimental = true",
 				"nvidia-container-runtime.discover-mode = \"not-legacy\"",
 				"nvidia-container-runtime.log-level = \"debug\"",
+				"nvidia-container-runtime.runtimes = [\"/some/runtime\",]",
 				"nvidia-ctk.path = \"/foo/bar/nvidia-ctk\"",
 			},
 			expectedConfig: &Config{
@@ -90,6 +92,7 @@ func TestGetConfig(t *testing.T) {
 					Experimental:  true,
 					DiscoverMode:  "not-legacy",
 					LogLevel:      "debug",
+					Runtimes:      []string{"/some/runtime"},
 				},
 				NVIDIACTKConfig: CTKConfig{
 					Path: "/foo/bar/nvidia-ctk",
@@ -106,6 +109,7 @@ func TestGetConfig(t *testing.T) {
 				"experimental = true",
 				"discover-mode = \"not-legacy\"",
 				"log-level = \"debug\"",
+				"runtimes = [\"/some/runtime\",]",
 				"[nvidia-ctk]",
 				"path = \"/foo/bar/nvidia-ctk\"",
 			},
@@ -118,6 +122,7 @@ func TestGetConfig(t *testing.T) {
 					Experimental:  true,
 					DiscoverMode:  "not-legacy",
 					LogLevel:      "debug",
+					Runtimes:      []string{"/some/runtime"},
 				},
 				NVIDIACTKConfig: CTKConfig{
 					Path: "/foo/bar/nvidia-ctk",

internal/config/runtime.go

@@ -21,6 +21,11 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+const (
+	dockerRuncExecutableName = "docker-runc"
+	runcExecutableName       = "runc"
+)
+
 // RuntimeConfig stores the config options for the NVIDIA Container Runtime
 type RuntimeConfig struct {
 	DebugFilePath string
@@ -28,6 +33,8 @@ type RuntimeConfig struct {
 	DiscoverMode  string
 	// LogLevel defines the logging level for the application
 	LogLevel string
+	// Runtimes defines the candidates for the low-level runtime
+	Runtimes []string
 }
 
 // getRuntimeConfigFrom reads the nvidia container runtime config from the specified toml Tree.
@@ -43,6 +50,15 @@ func getRuntimeConfigFrom(toml *toml.Tree) *RuntimeConfig {
 	cfg.DiscoverMode = toml.GetDefault("nvidia-container-runtime.discover-mode", cfg.DiscoverMode).(string)
 	cfg.LogLevel = toml.GetDefault("nvidia-container-runtime.log-level", cfg.LogLevel).(string)
 
+	configRuntimes := toml.Get("nvidia-container-runtime.runtimes")
+	if configRuntimes != nil {
+		var runtimes []string
+		for _, r := range configRuntimes.([]interface{}) {
+			runtimes = append(runtimes, r.(string))
+		}
+		cfg.Runtimes = runtimes
+	}
+
 	return cfg
 }
 
@@ -53,6 +69,10 @@ func GetDefaultRuntimeConfig() *RuntimeConfig {
 		Experimental:  false,
 		DiscoverMode:  "auto",
 		LogLevel:      logrus.InfoLevel.String(),
+		Runtimes: []string{
+			dockerRuncExecutableName,
+			runcExecutableName,
+		},
 	}
 
 	return &c