optimize config package

Signed-off-by: x893675 <x893675@icloud.com>

cmd/controller-manager/app/options/options.go

@@ -220,6 +220,8 @@ func (s *KubeSphereControllerManagerOptions) bindLeaderElectionFlags(l *leaderel
 		"of a leadership. This is only applicable if leader election is enabled.")
 }
 
+// MergeConfig merge new config without validation
+// When misconfigured, the app should just crash directly
 func (s *KubeSphereControllerManagerOptions) MergeConfig(cfg *controllerconfig.Config) {
 	s.KubernetesOptions = cfg.KubernetesOptions
 	s.DevopsOptions = cfg.DevopsOptions

cmd/controller-manager/app/server.go

@@ -48,7 +48,7 @@ import (
 
 func NewControllerManagerCommand() *cobra.Command {
 	s := options.NewKubeSphereControllerManagerOptions()
-	conf, configCh, err := controllerconfig.TryLoadFromDisk()
+	conf, err := controllerconfig.TryLoadFromDisk()
 	if err == nil {
 		// make sure LeaderElection is not nil
 		s = &options.KubeSphereControllerManagerOptions{
@@ -78,8 +78,7 @@ func NewControllerManagerCommand() *cobra.Command {
 				klog.Error(utilerrors.NewAggregate(errs))
 				os.Exit(1)
 			}
-
-			if err = Run(s, configCh, signals.SetupSignalHandler()); err != nil {
+			if err = Run(s, controllerconfig.WatchConfigChange(), signals.SetupSignalHandler()); err != nil {
 				klog.Error(err)
 				os.Exit(1)
 			}
@@ -115,31 +114,34 @@ func NewControllerManagerCommand() *cobra.Command {
 }
 
 func Run(s *options.KubeSphereControllerManagerOptions, configCh <-chan controllerconfig.Config, ctx context.Context) error {
-	ictx := controllerconfig.Context{}
-	ictx.RenewContext(context.TODO())
+	ictx, cancelFunc := context.WithCancel(context.TODO())
 	errCh := make(chan error)
 	defer close(errCh)
 	go func() {
-		if err := run(s, ictx.GetContext()); err != nil {
+		if err := run(s, ictx); err != nil {
 			errCh <- err
 		}
 	}()
 
+	// The ctx (signals.SetupSignalHandler()) is to control the entire program life cycle,
+	// The ictx(internal context)  is created here to control the life cycle of the controller-manager(all controllers, sharedInformer, webhook etc.)
+	// when config changed, stop server and renew context, start new server
 	for {
 		select {
 		case <-ctx.Done():
-			ictx.CancelContext()
+			cancelFunc()
 			return nil
 		case cfg := <-configCh:
-			ictx.CancelContext()
+			cancelFunc()
 			s.MergeConfig(&cfg)
-			ictx.RenewContext(context.TODO())
+			ictx, cancelFunc = context.WithCancel(context.TODO())
 			go func() {
-				if err := run(s, ictx.GetContext()); err != nil {
+				if err := run(s, ictx); err != nil {
 					errCh <- err
 				}
 			}()
 		case err := <-errCh:
+			cancelFunc()
 			return err
 		}
 	}

cmd/ks-apiserver/app/server.go

@@ -38,7 +38,7 @@ func NewAPIServerCommand() *cobra.Command {
 	s := options.NewServerRunOptions()
 
 	// Load configuration from file
-	conf, configCh, err := apiserverconfig.TryLoadFromDisk()
+	conf, err := apiserverconfig.TryLoadFromDisk()
 	if err == nil {
 		s = &options.ServerRunOptions{
 			GenericServerRunOptions: s.GenericServerRunOptions,
@@ -57,7 +57,7 @@ cluster's shared state through which all other components interact.`,
 			if errs := s.Validate(); len(errs) != 0 {
 				return utilerrors.NewAggregate(errs)
 			}
-			return Run(s, configCh, signals.SetupSignalHandler())
+			return Run(s, apiserverconfig.WatchConfigChange(), signals.SetupSignalHandler())
 		},
 		SilenceUsage: true,
 	}
@@ -89,31 +89,34 @@ cluster's shared state through which all other components interact.`,
 }
 
 func Run(s *options.ServerRunOptions, configCh <-chan apiserverconfig.Config, ctx context.Context) error {
-	ictx := apiserverconfig.Context{}
-	ictx.RenewContext(context.TODO())
+	ictx, cancelFunc := context.WithCancel(context.TODO())
 	errCh := make(chan error)
 	defer close(errCh)
 	go func() {
-		if err := run(s, ictx.GetContext()); err != nil {
+		if err := run(s, ictx); err != nil {
 			errCh <- err
 		}
 	}()
 
+	// The ctx (signals.SetupSignalHandler()) is to control the entire program life cycle,
+	// The ictx(internal context)  is created here to control the life cycle of the ks-apiserver(http server, sharedInformer etc.)
+	// when config change, stop server and renew context, start new server
 	for {
 		select {
 		case <-ctx.Done():
-			ictx.CancelContext()
+			cancelFunc()
 			return nil
 		case cfg := <-configCh:
-			ictx.CancelContext()
+			cancelFunc()
 			s.Config = &cfg
-			ictx.RenewContext(context.TODO())
+			ictx, cancelFunc = context.WithCancel(context.TODO())
 			go func() {
-				if err := run(s, ictx.GetContext()); err != nil {
+				if err := run(s, ictx); err != nil {
 					errCh <- err
 				}
 			}()
 		case err := <-errCh:
+			cancelFunc()
 			return err
 		}
 	}

pkg/apiserver/config/config.go

@@ -17,7 +17,6 @@ limitations under the License.
 package config
 
 import (
-	"context"
 	"fmt"
 	"reflect"
 	"strings"
@@ -86,8 +85,8 @@ import (
 // will be ignored.
 
 var (
-	once        sync.Once
-	cfgChangeCh = make(chan Config)
+	// singleton instance of config package
+	_config = defaultConfig()
 )
 
 const (
@@ -98,6 +97,61 @@ const (
 	defaultConfigurationPath = "/etc/kubesphere"
 )
 
+type config struct {
+	cfg         *Config
+	cfgChangeCh chan Config
+	watchOnce   sync.Once
+	loadOnce    sync.Once
+}
+
+func (c *config) watchConfig() <-chan Config {
+	c.watchOnce.Do(func() {
+		viper.WatchConfig()
+		viper.OnConfigChange(func(in fsnotify.Event) {
+			cfg := New()
+			if err := viper.Unmarshal(cfg); err != nil {
+				klog.Warning("config reload error", err)
+			} else {
+				c.cfgChangeCh <- *cfg
+			}
+		})
+	})
+	return c.cfgChangeCh
+}
+
+func (c *config) loadFromDisk() (*Config, error) {
+	var err error
+	c.loadOnce.Do(func() {
+		if err = viper.ReadInConfig(); err != nil {
+			if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
+				err = fmt.Errorf("error parsing configuration file %s", err)
+			}
+		}
+		err = viper.Unmarshal(c.cfg)
+	})
+	return c.cfg, err
+}
+
+func defaultConfig() *config {
+	viper.SetConfigName(defaultConfigurationName)
+	viper.AddConfigPath(defaultConfigurationPath)
+
+	// Load from current working directory, only used for debugging
+	viper.AddConfigPath(".")
+
+	// Load from Environment variables
+	viper.SetEnvPrefix("kubesphere")
+	viper.AutomaticEnv()
+	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
+
+	return &config{
+		cfg:         New(),
+		cfgChangeCh: make(chan Config),
+		watchOnce:   sync.Once{},
+		loadOnce:    sync.Once{},
+	}
+}
+
 // Config defines everything needed for apiserver to deal with external services
 type Config struct {
 	DevopsOptions         *jenkins.Options        `json:"devops,omitempty" yaml:"devops,omitempty" mapstructure:"devops"`
@@ -158,44 +212,13 @@ func New() *Config {
 
 // TryLoadFromDisk loads configuration from default location after server startup
 // return nil error if configuration file not exists
-func TryLoadFromDisk() (*Config, <-chan Config, error) {
-	once.Do(func() {
-		viper.SetConfigName(defaultConfigurationName)
-		viper.AddConfigPath(defaultConfigurationPath)
+func TryLoadFromDisk() (*Config, error) {
+	return _config.loadFromDisk()
+}
 
-		// Load from current working directory, only used for debugging
-		viper.AddConfigPath(".")
-
-		// Load from Environment variables
-		viper.SetEnvPrefix("kubesphere")
-		viper.AutomaticEnv()
-		viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
-
-		viper.WatchConfig()
-		viper.OnConfigChange(func(in fsnotify.Event) {
-			cfg := New()
-			if err := viper.Unmarshal(cfg); err != nil {
-				klog.Warning("config reload error", err)
-			} else {
-				cfgChangeCh <- *cfg
-			}
-		})
-	})
-
-	conf := New()
-	if err := viper.ReadInConfig(); err != nil {
-		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
-			return nil, cfgChangeCh, err
-		} else {
-			return nil, cfgChangeCh, fmt.Errorf("error parsing configuration file %s", err)
-		}
-	}
-
-	if err := viper.Unmarshal(conf); err != nil {
-		return nil, cfgChangeCh, err
-	}
-
-	return conf, cfgChangeCh, nil
+// WatchConfigChange return config change channel
+func WatchConfigChange() <-chan Config {
+	return _config.watchConfig()
 }
 
 // convertToMap simply converts config to map[string]bool
@@ -340,25 +363,3 @@ func (conf *Config) stripEmptyOptions() {
 		conf.GPUOptions = nil
 	}
 }
-
-type Context struct {
-	internalCtx       context.Context
-	internalCtxCancel context.CancelFunc
-	mu                sync.RWMutex
-}
-
-func (c *Context) GetContext() context.Context {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	return c.internalCtx
-}
-
-func (c *Context) RenewContext(ctx context.Context) {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	c.internalCtx, c.internalCtxCancel = context.WithCancel(ctx)
-}
-
-func (c *Context) CancelContext() {
-	c.internalCtxCancel()
-}

pkg/apiserver/config/config_test.go

@@ -240,7 +240,7 @@ func TestGet(t *testing.T) {
 	conf.RedisOptions.Password = "P@88w0rd"
 	os.Setenv("KUBESPHERE_REDIS_PASSWORD", "P@88w0rd")
 
-	conf2, _, err := TryLoadFromDisk()
+	conf2, err := TryLoadFromDisk()
 	if err != nil {
 		t.Fatal(err)
 	}