[node.sh] refactor kmsClientProvider to kmsProvider and awsConfigGetter

cmd/harmony/blsloader/helper.go

@@ -86,20 +86,8 @@ func (loader *kmsSingleBlsLoader) loadKeys() (multibls.PrivateKeys, error) {
 	return multibls.GetPrivateKeys(secretKey), nil
 }
 
-func (loader *kmsSingleBlsLoader) getKmsClientProvider() (kmsClientProvider, error) {
-	switch loader.awsCfgSrcType {
-	case AwsCfgSrcFile:
-		if stringIsSet(loader.awsConfigFile) {
-			return newFileKmsProvider(*loader.awsConfigFile), nil
-		}
-		return newSharedKmsProvider(), nil
-	case AwsCfgSrcPrompt:
-		return newPromptKmsProvider(defKmsPromptTimeout), nil
-	case AwsCfgSrcShared:
-		return newSharedKmsProvider(), nil
-	default:
-		return nil, errors.New("unknown aws config source type")
-	}
+func (loader *kmsSingleBlsLoader) getKmsClientProvider() (kmsProvider, error) {
+	return newLazyKmsProvider(loader.kmsProviderConfig)
 }
 
 // blsDirLoader is the helper structure for loading bls keys in a directory
@@ -111,7 +99,7 @@ type blsDirLoader struct {
 
 	// providers in process
 	pps []passProvider
-	kcp kmsClientProvider
+	kcp kmsProvider
 	// result field
 	secretKeys []*bls_core.SecretKey
 }
@@ -159,20 +147,8 @@ func (loader *blsDirLoader) getPromptPassProvider() passProvider {
 	return provider
 }
 
-func (loader *blsDirLoader) getKmsClientProvider() (kmsClientProvider, error) {
-	switch loader.awsCfgSrcType {
-	case AwsCfgSrcFile:
-		if stringIsSet(loader.awsConfigFile) {
-			return newFileKmsProvider(*loader.awsConfigFile), nil
-		}
-		return newSharedKmsProvider(), nil
-	case AwsCfgSrcPrompt:
-		return newPromptKmsProvider(defKmsPromptTimeout), nil
-	case AwsCfgSrcShared:
-		return newSharedKmsProvider(), nil
-	default:
-		return nil, errors.New("unknown aws config source type")
-	}
+func (loader *blsDirLoader) getKmsClientProvider() (kmsProvider, error) {
+	return newLazyKmsProvider(loader.kmsProviderConfig)
 }
 
 func (loader *blsDirLoader) loadKeyFiles() (multibls.PrivateKeys, error) {
@@ -190,7 +166,7 @@ func (loader *blsDirLoader) processFileWalk(path string, info os.FileInfo, err e
 			// unexpected error, return the error and break the file walk loop
 			return err
 		}
-		// expected error. Skipping these files
+		// errors to be skipped. Skipping these files
 		skipStr := fmt.Sprintf("Skipping [%s]: %v\n", path, err)
 		console.println(skipStr)
 		return nil

cmd/harmony/blsloader/kmsProvider.go

@@ -37,49 +37,61 @@ type kmsProviderConfig struct {
 	awsConfigFile *string
 }
 
-func (cfg kmsProviderConfig) validate() error {
-	if !cfg.awsCfgSrcType.isValid() {
+func (config kmsProviderConfig) validate() error {
+	if !config.awsCfgSrcType.isValid() {
 		return errors.New("unknown AwsCfgSrcType")
 	}
-	if cfg.awsCfgSrcType == AwsCfgSrcFile {
-		if !stringIsSet(cfg.awsConfigFile) {
+	if config.awsCfgSrcType == AwsCfgSrcFile {
+		if !stringIsSet(config.awsConfigFile) {
 			return errors.New("config field AwsConfig file must set for AwsCfgSrcFile")
 		}
-		if !isFile(*cfg.awsConfigFile) {
-			return fmt.Errorf("aws config file not exist %v", *cfg.awsConfigFile)
+		if !isFile(*config.awsConfigFile) {
+			return fmt.Errorf("aws config file not exist %v", *config.awsConfigFile)
 		}
 	}
 	return nil
 }
 
-// kmsClientProvider provides the kms client. Implemented by
-//   baseKMSProvider - abstract implementation
-//   sharedKMSProvider - provide the client with default .aws folder
-//   fileKMSProvider - provide the aws config with a json file
-//   promptKMSProvider - provide the config field from prompt with time out
-type kmsClientProvider interface {
-	// getKMSClient returns the KMSClient of the kmsClientProvider with lazy loading.
+// kmsProvider provide the aws kms client
+type kmsProvider interface {
 	getKMSClient() (*kms.KMS, error)
-
-	// toStr return the string presentation of kmsClientProvider
-	toStr() string
 }
 
-type getAwsCfgFunc func() (*AwsConfig, error)
+// lazyKmsProvider provide the kms client with singleton lazy initialization with config get
+// from awsConfigGetter for aws credential and regions loading.
+type lazyKmsProvider struct {
+	acGetter awsConfigGetter
 
-// baseKMSProvider provide the kms client with singleton initialization through
-// function getConfig for aws credential and regions loading.
-type baseKMSProvider struct {
 	client *kms.KMS
 	err    error
 	once   sync.Once
+}
 
-	getAWSConfig getAwsCfgFunc
+// newLazyKmsProvider creates a kmsProvider with the given config
+func newLazyKmsProvider(config kmsProviderConfig) (*lazyKmsProvider, error) {
+	var acg awsConfigGetter
+	switch config.awsCfgSrcType {
+	case AwsCfgSrcFile:
+		if stringIsSet(config.awsConfigFile) {
+			acg = newFileACGetter(*config.awsConfigFile)
+		} else {
+			acg = newSharedAwsConfigGetter()
+		}
+	case AwsCfgSrcPrompt:
+		acg = newPromptACGetter(defKmsPromptTimeout)
+	case AwsCfgSrcShared:
+		acg = newSharedAwsConfigGetter()
+	default:
+		return nil, errors.New("unknown aws config source type")
+	}
+	return &lazyKmsProvider{
+		acGetter: acg,
+	}, nil
 }
 
-func (provider *baseKMSProvider) getKMSClient() (*kms.KMS, error) {
+func (provider *lazyKmsProvider) getKMSClient() (*kms.KMS, error) {
 	provider.once.Do(func() {
-		cfg, err := provider.getAWSConfig()
+		cfg, err := provider.acGetter.getAwsConfig()
 		if err != nil {
 			provider.err = err
 			return
@@ -92,94 +104,80 @@ func (provider *baseKMSProvider) getKMSClient() (*kms.KMS, error) {
 	return provider.client, nil
 }
 
-func (provider *baseKMSProvider) toStr() string {
-	return "not implemented"
+// awsConfigGetter provides the aws config. Implemented by
+//   sharedACGetter - provide the nil to use shared AWS configuration
+//   fileACGetter   - provide the aws config with a json file
+//   promptACGetter - provide the config field from prompt with time out
+type awsConfigGetter interface {
+	getAwsConfig() (*AwsConfig, error)
+	String() string
 }
 
-// sharedKMSProvider provide the kms session with the default aws config
-// locates in directory $HOME/.aws/config
-type sharedKMSProvider struct {
-	baseKMSProvider
-}
+// sharedACGetter returns nil for getAwsConfig to use shared aws configurations
+type sharedACGetter struct{}
 
-func newSharedKmsProvider() *sharedKMSProvider {
-	provider := &sharedKMSProvider{baseKMSProvider{}}
-	provider.baseKMSProvider.getAWSConfig = provider.getAWSConfig
-	return provider
+func newSharedAwsConfigGetter() *sharedACGetter {
+	return &sharedACGetter{}
 }
 
-// TODO(Jacky): set getAwsConfig into a function, not bind with structure
-func (provider *sharedKMSProvider) getAWSConfig() (*AwsConfig, error) {
+func (getter *sharedACGetter) getAwsConfig() (*AwsConfig, error) {
 	return nil, nil
 }
 
-func (provider *sharedKMSProvider) toStr() string {
+func (getter *sharedACGetter) String() string {
 	return "shared aws config"
 }
 
-// fileKMSProvider provide the kms session from a file with json data of structure
-// AwsConfig
-type fileKMSProvider struct {
-	baseKMSProvider
-
+// fileACGetter get aws config through a customized json file
+type fileACGetter struct {
 	file string
 }
 
-func newFileKmsProvider(file string) *fileKMSProvider {
-	provider := &fileKMSProvider{
-		baseKMSProvider: baseKMSProvider{},
-		file:            file,
-	}
-	provider.baseKMSProvider.getAWSConfig = provider.getAWSConfig
-	return provider
+func newFileACGetter(file string) *fileACGetter {
+	return &fileACGetter{file}
 }
 
-func (provider *fileKMSProvider) getAWSConfig() (*AwsConfig, error) {
-	b, err := ioutil.ReadFile(provider.file)
+func (getter *fileACGetter) getAwsConfig() (*AwsConfig, error) {
+	b, err := ioutil.ReadFile(getter.file)
 	if err != nil {
 		return nil, err
 	}
-	var cfg *AwsConfig
-	if err := json.Unmarshal(b, cfg); err != nil {
+	var cfg AwsConfig
+	if err := json.Unmarshal(b, &cfg); err != nil {
 		return nil, err
 	}
-	return cfg, nil
+	return &cfg, nil
 }
 
-func (provider *fileKMSProvider) toStr() string {
-	return fmt.Sprintf("file %v", provider.file)
+func (getter *fileACGetter) String() string {
+	return fmt.Sprintf("file %v", getter.file)
 }
 
-// promptKMSProvider provide a user interactive console for AWS config.
-// Three fields are asked:
+// promptACGetter provide a user interactive console for AWS config.
+// Four fields are asked:
 //    1. AccessKey  	2. SecretKey		3. Region
 // Each field is asked with a timeout mechanism.
-type promptKMSProvider struct {
-	baseKMSProvider
-
+type promptACGetter struct {
 	timeout time.Duration
 }
 
-func newPromptKmsProvider(timeout time.Duration) *promptKMSProvider {
-	provider := &promptKMSProvider{
-		baseKMSProvider: baseKMSProvider{},
-		timeout:         timeout,
+func newPromptACGetter(timeout time.Duration) *promptACGetter {
+	return &promptACGetter{
+		timeout: timeout,
 	}
-	provider.baseKMSProvider.getAWSConfig = provider.getAWSConfig
-	return provider
 }
 
-func (provider *promptKMSProvider) getAWSConfig() (*AwsConfig, error) {
+func (getter *promptACGetter) getAwsConfig() (*AwsConfig, error) {
 	console.println("Please provide AWS configurations for KMS encoded BLS keys:")
-	accessKey, err := provider.prompt("  AccessKey:")
+	accessKey, err := getter.prompt("  AccessKey:")
 	if err != nil {
 		return nil, fmt.Errorf("cannot get aws access key: %v", err)
 	}
-	secretKey, err := provider.prompt("  SecretKey:")
+	secretKey, err := getter.prompt("  SecretKey:")
 	if err != nil {
 		return nil, fmt.Errorf("cannot get aws secret key: %v", err)
 	}
-	region, err := provider.prompt("Region:")
+	region, err := getter.prompt("Region:")
 	if err != nil {
 		return nil, fmt.Errorf("cannot get aws region: %v", err)
 	}
@@ -192,17 +190,17 @@ func (provider *promptKMSProvider) getAWSConfig() (*AwsConfig, error) {
 }
 
 // prompt prompt the user to input a string for a certain field with timeout.
-func (provider *promptKMSProvider) prompt(hint string) (string, error) {
+func (getter *promptACGetter) prompt(hint string) (string, error) {
 	var (
 		res string
 		err error
 
 		finished = make(chan struct{})
-		timedOut = time.After(provider.timeout)
+		timedOut = time.After(getter.timeout)
 	)
 
 	go func() {
-		res, err = provider.threadedPrompt(hint)
+		res, err = getter.threadedPrompt(hint)
 		close(finished)
 	}()
 
@@ -216,12 +214,12 @@ func (provider *promptKMSProvider) prompt(hint string) (string, error) {
 	}
 }
 
-func (provider *promptKMSProvider) threadedPrompt(hint string) (string, error) {
+func (getter *promptACGetter) threadedPrompt(hint string) (string, error) {
 	console.print(hint)
 	return console.readPassword()
 }
 
-func (provider *promptKMSProvider) toStr() string {
+func (getter *promptACGetter) String() string {
 	return "prompt"
 }
 

cmd/harmony/blsloader/loader.go

@@ -20,41 +20,13 @@ func LoadKeys(cfg Config) (multibls.PrivateKeys, error) {
 	return helper.loadKeys()
 }
 
-func getHelper(cfg Config) (loadHelper, error) {
-	switch {
-	case stringIsSet(cfg.BlsKeyFile):
-		switch filepath.Ext(*cfg.BlsKeyFile) {
-		case basicKeyExt:
-			return &basicSingleBlsLoader{
-				blsKeyFile:         *cfg.BlsKeyFile,
-				passProviderConfig: cfg.getPassProviderConfig(),
-			}, nil
-		case kmsKeyExt:
-			return &kmsSingleBlsLoader{
-				blsKeyFile:        *cfg.BlsKeyFile,
-				kmsProviderConfig: cfg.getKmsProviderConfig(),
-			}, nil
-		default:
-			return nil, errors.New("unknown extension")
-		}
-	case stringIsSet(cfg.BlsDir):
-		return &blsDirLoader{
-			dirPath:            *cfg.BlsDir,
-			passProviderConfig: cfg.getPassProviderConfig(),
-			kmsProviderConfig:  cfg.getKmsProviderConfig(),
-		}, nil
-	default:
-		return nil, errors.New("either BlsKeyFile or BlsDir must be set")
-	}
-}
-
 // Loader is the structure to load bls keys.
 type Config struct {
 	// source for bls key loading. At least one of the BlsKeyFile and BlsDir
 	// need to be provided.
 	//
 	// BlsKeyFile defines a single key file to load from. Based on the file
-	// extension, decryption with passphrase or aws kms will be used.
+	// extension, decryption with either passphrase or aws kms will be used.
 	BlsKeyFile *string
 	// BlsDir defines a file directory to load keys from.
 	BlsDir *string
@@ -134,3 +106,31 @@ func (cfg *Config) getKmsProviderConfig() kmsProviderConfig {
 		awsConfigFile: cfg.AwsConfigFile,
 	}
 }
+
+func getHelper(cfg Config) (loadHelper, error) {
+	switch {
+	case stringIsSet(cfg.BlsKeyFile):
+		switch filepath.Ext(*cfg.BlsKeyFile) {
+		case basicKeyExt:
+			return &basicSingleBlsLoader{
+				blsKeyFile:         *cfg.BlsKeyFile,
+				passProviderConfig: cfg.getPassProviderConfig(),
+			}, nil
+		case kmsKeyExt:
+			return &kmsSingleBlsLoader{
+				blsKeyFile:        *cfg.BlsKeyFile,
+				kmsProviderConfig: cfg.getKmsProviderConfig(),
+			}, nil
+		default:
+			return nil, errors.New("unknown extension")
+		}
+	case stringIsSet(cfg.BlsDir):
+		return &blsDirLoader{
+			dirPath:            *cfg.BlsDir,
+			passProviderConfig: cfg.getPassProviderConfig(),
+			kmsProviderConfig:  cfg.getKmsProviderConfig(),
+		}, nil
+	default:
+		return nil, errors.New("either BlsKeyFile or BlsDir must be set")
+	}
+}

cmd/harmony/blsloader/passProvider.go

@@ -25,8 +25,8 @@ func (config passProviderConfig) validate() error {
 // passProvider is the interface to provide the passphrase of a bls keys.
 // Implemented by
 // 	  promptPassProvider - provide passphrase through user-interactive prompt
-//    filePassProvider - provide passphrase from a .pass file
-//    dirPassProvider - provide passphrase from .pass files in a directory
+//    filePassProvider   - provide passphrase from a .pass file
+//    dirPassProvider    - provide passphrase from .pass files in a directory
 type passProvider interface {
 	toStr() string
 	getPassphrase(keyFile string) (string, error)

cmd/harmony/blsloader/utils.go

@@ -47,7 +47,7 @@ func loadBasicKeyWithProvider(blsKeyFile string, pp passProvider) (*bls_core.Sec
 }
 
 // loadKmsKeyFromFile loads a single KMS BLS key from file
-func loadKmsKeyFromFile(blsKeyFile string, kcp kmsClientProvider) (*bls_core.SecretKey, error) {
+func loadKmsKeyFromFile(blsKeyFile string, kcp kmsProvider) (*bls_core.SecretKey, error) {
 	if kcp == nil {
 		return nil, errNilKMSClientProvider
 	}