Add support for containerd version 3 config

This change adds support for containerd configs with version=3.
From the perspective of the runtime configuration the contents of the
config are the same. This means that we just have to load the new
version and ensure that this is propagated to the generated config.

Note that we still use a default config of version=2 since we need to
ensure compatibility with older containerd versions (1.6.x and 1.7.x).

Signed-off-by: Sam Lockart <[email protected]>
Signed-off-by: Evan Lezar <[email protected]>

Author: alam0rt

pkg/config/engine/containerd/config_v2.go renamed to pkg/config/engine/containerd/config.go

@@ -30,7 +30,7 @@ func (c *Config) AddRuntime(name string, path string, setAsDefault bool) error {
 	}
 	config := *c.Tree
 
-	config.Set("version", int64(2))
+	config.Set("version", c.Version)
 
 	runtimeNamesForConfig := engine.GetLowLevelRuntimes(c)
 	for _, r := range runtimeNamesForConfig {

pkg/config/engine/containerd/config_v2_test.go

@@ -195,6 +195,68 @@ func TestAddRuntime(t *testing.T) {
 						SystemdCgroup = false
 				`,
 		},
+		{
+			description: "empty v3 spec is supported",
+			config: `
+			version = 3
+			`,
+			expectedConfig: `
+			version = 3
+			[plugins]
+			[plugins."io.containerd.grpc.v1.cri"]
+				[plugins."io.containerd.grpc.v1.cri".containerd]
+				[plugins."io.containerd.grpc.v1.cri".containerd.runtimes]
+					[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.test]
+					privileged_without_host_devices = false
+					runtime_engine = ""
+					runtime_root = ""
+					runtime_type = "io.containerd.runc.v2"
+					[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.test.options]
+						BinaryName = "/usr/bin/test"
+			`,
+			expectedError: nil,
+		},
+		{
+			description: "v3 spec is supported",
+			config: `
+			version = 3
+			[plugins]
+			[plugins."io.containerd.grpc.v1.cri"]
+				[plugins."io.containerd.grpc.v1.cri".containerd]
+				[plugins."io.containerd.grpc.v1.cri".containerd.runtimes]
+					[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
+					privileged_without_host_devices = true
+					runtime_engine = "engine"
+					runtime_root = "root"
+					runtime_type = "type"
+					[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
+						BinaryName = "/usr/bin/runc"
+						SystemdCgroup = true
+			`,
+			expectedConfig: `
+			version = 3
+			[plugins]
+			[plugins."io.containerd.grpc.v1.cri"]
+				[plugins."io.containerd.grpc.v1.cri".containerd]
+				[plugins."io.containerd.grpc.v1.cri".containerd.runtimes]
+					[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
+					privileged_without_host_devices = true
+					runtime_engine = "engine"
+					runtime_root = "root"
+					runtime_type = "type"
+					[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
+						BinaryName = "/usr/bin/runc"
+						SystemdCgroup = true
+					[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.test]
+					privileged_without_host_devices = true
+					runtime_engine = "engine"
+					runtime_root = "root"
+					runtime_type = "type"
+					[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.test.options]
+						BinaryName = "/usr/bin/test"
+						SystemdCgroup = true
+				`,
+		},
 	}
 
 	for _, tc := range testCases {

pkg/config/engine/containerd/containerd.go

@@ -24,9 +24,15 @@ import (
 	"github.com/NVIDIA/nvidia-container-toolkit/pkg/config/toml"
 )
 
+const (
+	defaultConfigVersion = 2
+	defaultRuntimeType   = "io.containerd.runc.v2"
+)
+
 // Config represents the containerd config
 type Config struct {
 	*toml.Tree
+	Version               int64
 	Logger                logger.Interface
 	RuntimeType           string
 	UseDefaultRuntimeName bool
@@ -55,7 +61,8 @@ func (c *containerdCfgRuntime) GetBinaryPath() string {
 // New creates a containerd config with the specified options
 func New(opts ...Option) (engine.Interface, error) {
 	b := &builder{
-		runtimeType: defaultRuntimeType,
+		configVersion: defaultConfigVersion,
+		runtimeType:   defaultRuntimeType,
 	}
 	for _, opt := range opts {
 		opt(b)
@@ -72,45 +79,41 @@ func New(opts ...Option) (engine.Interface, error) {
 		return nil, fmt.Errorf("failed to load config: %v", err)
 	}
 
+	configVersion, err := b.parseVersion(tomlConfig)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse config version: %w", err)
+	}
+
 	cfg := &Config{
 		Tree:                  tomlConfig,
+		Version:               configVersion,
 		Logger:                b.logger,
 		RuntimeType:           b.runtimeType,
-		UseDefaultRuntimeName: b.useLegacyConfig,
+		UseDefaultRuntimeName: configVersion == 1,
 		ContainerAnnotations:  b.containerAnnotations,
 	}
 
-	version, err := cfg.parseVersion(b.useLegacyConfig)
-	if err != nil {
-		return nil, fmt.Errorf("failed to parse config version: %v", err)
-	}
-	switch version {
+	switch configVersion {
 	case 1:
 		return (*ConfigV1)(cfg), nil
-	case 2:
+	case 2, 3:
 		return cfg, nil
 	}
-
-	return nil, fmt.Errorf("unsupported config version: %v", version)
+	return nil, fmt.Errorf("unsupported config version: %v", configVersion)
 }
 
 // parseVersion returns the version of the config
-func (c *Config) parseVersion(useLegacyConfig bool) (int, error) {
-	defaultVersion := 2
-	if useLegacyConfig {
-		defaultVersion = 1
-	}
-
+func (b *builder) parseVersion(c *toml.Tree) (int64, error) {
 	switch v := c.Get("version").(type) {
 	case nil:
 		switch len(c.Keys()) {
 		case 0: // No config exists, or the config file is empty, use version inferred from containerd
-			return defaultVersion, nil
+			return int64(b.configVersion), nil
 		default: // A config file exists, has content, and no version is set
 			return 1, nil
 		}
 	case int64:
-		return int(v), nil
+		return v, nil
 	default:
 		return -1, fmt.Errorf("unsupported type for version field: %v", v)
 	}

pkg/config/engine/containerd/option.go

@@ -21,16 +21,12 @@ import (
 	"github.com/NVIDIA/nvidia-container-toolkit/pkg/config/toml"
 )
 
-const (
-	defaultRuntimeType = "io.containerd.runc.v2"
-)
-
 type builder struct {
 	logger               logger.Interface
 	configSource         toml.Loader
+	configVersion        int
 	path                 string
 	runtimeType          string
-	useLegacyConfig      bool
 	containerAnnotations []string
 }
 
@@ -68,7 +64,14 @@ func WithRuntimeType(runtimeType string) Option {
 // WithUseLegacyConfig sets the useLegacyConfig flag for the config builder
 func WithUseLegacyConfig(useLegacyConfig bool) Option {
 	return func(b *builder) {
-		b.useLegacyConfig = useLegacyConfig
+		b.configVersion = 1
+	}
+}
+
+// WithConfigVersion sets the config version for the config builder
+func WithConfigVersion(configVersion int) Option {
+	return func(b *builder) {
+		b.configVersion = configVersion
 	}
 }