Add support for adding additional containerd configs

This allow for options such as SystemdCgroup to be optionally set.

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

cmd/nvidia-ctk/runtime/configure/configure.go

@@ -17,6 +17,7 @@
 package configure
 
 import (
+	"encoding/json"
 	"fmt"
 	"path/filepath"
 
@@ -66,6 +67,8 @@ type config struct {
 	mode           string
 	hookFilePath   string
 
+	runtimeConfigOverrideJSON string
+
 	nvidiaRuntime struct {
 		name         string
 		path         string
@@ -153,6 +156,13 @@ func (m command) build() *cli.Command {
 			Usage:       "Enable CDI in the configured runtime",
 			Destination: &config.cdi.enabled,
 		},
+		&cli.StringFlag{
+			Name:        "runtime-config-override",
+			Destination: &config.runtimeConfigOverrideJSON,
+			Usage:       "specify additional runtime options as a JSON string. The paths are relative to the runtime config.",
+			Value:       "{}",
+			EnvVars:     []string{"RUNTIME_CONFIG_OVERRIDE"},
+		},
 	}
 
 	return &configure
@@ -194,6 +204,11 @@ func (m command) validateFlags(c *cli.Context, config *config) error {
 		config.cdi.enabled = false
 	}
 
+	if config.runtimeConfigOverrideJSON != "" && config.runtime != "containerd" {
+		m.logger.Warningf("Ignoring runtime-config-override flag for %v", config.runtime)
+		config.runtimeConfigOverrideJSON = ""
+	}
+
 	return nil
 }
 
@@ -237,10 +252,16 @@ func (m command) configureConfigFile(c *cli.Context, config *config) error {
 		return fmt.Errorf("unable to load config for runtime %v: %v", config.runtime, err)
 	}
 
+	runtimeConfigOverride, err := config.runtimeConfigOverride()
+	if err != nil {
+		return fmt.Errorf("unable to parse config overrides: %w", err)
+	}
+
 	err = cfg.AddRuntime(
 		config.nvidiaRuntime.name,
 		config.nvidiaRuntime.path,
 		config.nvidiaRuntime.setAsDefault,
+		runtimeConfigOverride,
 	)
 	if err != nil {
 		return fmt.Errorf("unable to update config: %v", err)
@@ -293,6 +314,20 @@ func (c *config) getOuputConfigPath() string {
 	return c.resolveConfigFilePath()
 }
 
+// runtimeConfigOverride converts the specified runtimeConfigOverride JSON string to a map.
+func (o *config) runtimeConfigOverride() (map[string]interface{}, error) {
+	if o.runtimeConfigOverrideJSON == "" {
+		return nil, nil
+	}
+
+	runtimeOptions := make(map[string]interface{})
+	if err := json.Unmarshal([]byte(o.runtimeConfigOverrideJSON), &runtimeOptions); err != nil {
+		return nil, fmt.Errorf("failed to read %v as JSON: %w", o.runtimeConfigOverrideJSON, err)
+	}
+
+	return runtimeOptions, nil
+}
+
 // configureOCIHook creates and configures the OCI hook for the NVIDIA runtime
 func (m *command) configureOCIHook(c *cli.Context, config *config) error {
 	err := ocihook.CreateHook(config.hookFilePath, config.nvidiaRuntime.hookPath)