Refactor the engine.Interface such that the Set() API does not return an extraneous error

Signed-off-by: Christopher Desiniotis <cdesiniotis@nvidia.com>

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

@@ -308,9 +308,11 @@ func enableCDI(config *config, cfg engine.Interface) error {
 	}
 	switch config.runtime {
 	case "containerd":
-		return cfg.Set("enable_cdi", true)
+		cfg.Set("enable_cdi", true)
 	case "docker":
-		return cfg.Set("experimental", true)
+		cfg.Set("experimental", true)
-	}
+	default:
 		return fmt.Errorf("enabling CDI in %s is not supported", config.runtime)
 	}
+	return nil
+}

pkg/config/engine/api.go

@@ -20,7 +20,7 @@ package engine
 type Interface interface {
 	DefaultRuntime() string
 	AddRuntime(string, string, bool) error
-	Set(string, interface{}) error
+	Set(string, interface{})
 	RemoveRuntime(string) error
 	Save(string) (int64, error)
 }

pkg/config/engine/containerd/config_v1.go

@@ -135,11 +135,10 @@ func (c *ConfigV1) RemoveRuntime(name string) error {
 }
 
 // SetOption sets the specified containerd option.
-func (c *ConfigV1) Set(key string, value interface{}) error {
+func (c *ConfigV1) Set(key string, value interface{}) {
 	config := *c.Tree
 	config.SetPath([]string{"plugins", "cri", "containerd", key}, value)
 	*c.Tree = config
-	return nil
 }
 
 // Save wrotes the config to a file

pkg/config/engine/containerd/config_v2.go

@@ -91,11 +91,10 @@ func (c *Config) getRuntimeAnnotations(path []string) ([]string, error) {
 }
 
 // Set sets the specified containerd option.
-func (c *Config) Set(key string, value interface{}) error {
+func (c *Config) Set(key string, value interface{}) {
 	config := *c.Tree
 	config.SetPath([]string{"plugins", "io.containerd.grpc.v1.cri", key}, value)
 	*c.Tree = config
-	return nil
 }
 
 // DefaultRuntime returns the default runtime for the cri-o config

pkg/config/engine/containerd/containerd.go

@@ -31,6 +31,8 @@ type Config struct {
 	ContainerAnnotations  []string
 }
 
+var _ engine.Interface = (*Config)(nil)
+
 // New creates a containerd config with the specified options
 func New(opts ...Option) (engine.Interface, error) {
 	b := &builder{}

pkg/config/engine/crio/crio.go

@@ -27,6 +27,8 @@ import (
 // Config represents the cri-o config
 type Config toml.Tree
 
+var _ engine.Interface = (*Config)(nil)
+
 // New creates a cri-o config with the specified options
 func New(opts ...Option) (engine.Interface, error) {
 	b := &builder{}
@@ -100,9 +102,7 @@ func (c *Config) RemoveRuntime(name string) error {
 }
 
 // Set is not supported for cri-o configs.
-func (c *Config) Set(key string, value interface{}) error {
+func (c *Config) Set(key string, value interface{}) {}
-	return fmt.Errorf("Set is not supported for crio configs")
-}
 
 // Save writes the config to the specified path
 func (c Config) Save(path string) (int64, error) {

pkg/config/engine/docker/docker.go

@@ -32,6 +32,8 @@ const (
 // TODO: This should not be public, but we need to access it from the tests in tools/container/docker
 type Config map[string]interface{}
 
+var _ engine.Interface = (*Config)(nil)
+
 // New creates a docker config with the specified options
 func New(opts ...Option) (engine.Interface, error) {
 	b := &builder{}
@@ -115,9 +117,8 @@ func (c *Config) RemoveRuntime(name string) error {
 }
 
 // Set sets the specified docker option
-func (c *Config) Set(key string, value interface{}) error {
+func (c *Config) Set(key string, value interface{}) {
 	(*c)[key] = value
-	return nil
 }
 
 // Save writes the config to the specified path