Add new factory unmarshaler to all components, deprecate old way

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

component/component.go

@@ -17,6 +17,8 @@ package component
 import (
 	"context"
 
+	"github.com/spf13/viper"
+
 	"go.opentelemetry.io/collector/config/configmodels"
 )
 
@@ -86,3 +88,22 @@ type Factory interface {
 	// Type gets the type of the component created by this factory.
 	Type() configmodels.Type
 }
+
+// FactoryUnmarshaler interface is an optional interface that if implemented by a factory,
+// the config loader will use to unmarshal the config.
+type FactoryUnmarshaler interface {
+	// Unmarshal is a function that un-marshals a viper data into a config struct in a custom way.
+	// componentViperSection *viper.Viper
+	//   The config for this specific component. May be nil or empty if no config available.
+	// intoCfg interface{}
+	//   An empty interface wrapping a pointer to the config struct to unmarshal into.
+	Unmarshal(componentViperSection *viper.Viper, intoCfg interface{}) error
+}
+
+// CustomUnmarshaler is a function that un-marshals a viper data into a config struct
+// in a custom way.
+// componentViperSection *viper.Viper
+//   The config for this specific component. May be nil or empty if no config available.
+// intoCfg interface{}
+//   An empty interface wrapping a pointer to the config struct to unmarshal into.
+type CustomUnmarshaler func(componentViperSection *viper.Viper, intoCfg interface{}) error

component/componenttest/example_factories.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/spf13/viper"
 	"go.uber.org/zap"
 
 	"go.opentelemetry.io/collector/component"
@@ -56,11 +57,6 @@ func (f *ExampleReceiverFactory) Type() configmodels.Type {
 	return "examplereceiver"
 }
 
-// CustomUnmarshaler returns nil because we don't need custom unmarshaling for this factory.
-func (f *ExampleReceiverFactory) CustomUnmarshaler() component.CustomUnmarshaler {
-	return nil
-}
-
 // CreateDefaultConfig creates the default configuration for the Receiver.
 func (f *ExampleReceiverFactory) CreateDefaultConfig() configmodels.Receiver {
 	return &ExampleReceiver{
@@ -77,6 +73,11 @@ func (f *ExampleReceiverFactory) CreateDefaultConfig() configmodels.Receiver {
 	}
 }
 
+// CustomUnmarshaler implements the deprecated way to provide custom unmarshalers.
+func (f *ExampleReceiverFactory) CustomUnmarshaler() component.CustomUnmarshaler {
+	return nil
+}
+
 // CreateTraceReceiver creates a trace receiver based on this config.
 func (f *ExampleReceiverFactory) CreateTraceReceiver(
 	_ context.Context,
@@ -163,31 +164,8 @@ var exampleReceivers = map[configmodels.Receiver]*ExampleReceiverProducer{}
 // MultiProtoReceiver is for testing purposes. We are defining an example multi protocol
 // config and factory for "multireceiver" receiver type.
 type MultiProtoReceiver struct {
-	TypeVal   configmodels.Type                   `mapstructure:"-"`
-	NameVal   string                              `mapstructure:"-"`
-	Protocols map[string]MultiProtoReceiverOneCfg `mapstructure:"protocols"`
-}
-
-var _ configmodels.Receiver = (*MultiProtoReceiver)(nil)
-
-// Name gets the exporter name.
-func (rs *MultiProtoReceiver) Name() string {
-	return rs.NameVal
-}
-
-// SetName sets the receiver name.
-func (rs *MultiProtoReceiver) SetName(name string) {
-	rs.NameVal = name
-}
-
-// Type sets the receiver type.
-func (rs *MultiProtoReceiver) Type() configmodels.Type {
-	return rs.TypeVal
-}
-
-// SetType sets the receiver type.
-func (rs *MultiProtoReceiver) SetType(typeStr configmodels.Type) {
-	rs.TypeVal = typeStr
+	configmodels.ReceiverSettings `mapstructure:",squash"`            // squash ensures fields are correctly decoded in embedded struct
+	Protocols                     map[string]MultiProtoReceiverOneCfg `mapstructure:"protocols"`
 }
 
 // MultiProtoReceiverOneCfg is multi proto receiver config.
@@ -205,16 +183,18 @@ func (f *MultiProtoReceiverFactory) Type() configmodels.Type {
 	return "multireceiver"
 }
 
-// CustomUnmarshaler returns nil because we don't need custom unmarshaling for this factory.
-func (f *MultiProtoReceiverFactory) CustomUnmarshaler() component.CustomUnmarshaler {
-	return nil
+// Unmarshal implements the FactoryUnmarshaler interface.
+func (f *MultiProtoReceiverFactory) Unmarshal(componentViperSection *viper.Viper, intoCfg interface{}) error {
+	return componentViperSection.UnmarshalExact(intoCfg)
 }
 
 // CreateDefaultConfig creates the default configuration for the Receiver.
 func (f *MultiProtoReceiverFactory) CreateDefaultConfig() configmodels.Receiver {
 	return &MultiProtoReceiver{
-		TypeVal: f.Type(),
-		NameVal: string(f.Type()),
+		ReceiverSettings: configmodels.ReceiverSettings{
+			TypeVal: f.Type(),
+			NameVal: string(f.Type()),
+		},
 		Protocols: map[string]MultiProtoReceiverOneCfg{
 			"http": {
 				Endpoint:     "example.com:8888",
@@ -277,6 +257,13 @@ func (f *ExampleExporterFactory) CreateDefaultConfig() configmodels.Exporter {
 	}
 }
 
+// CustomUnmarshaler implements the deprecated way to provide custom unmarshalers.
+func (f *ExampleExporterFactory) CustomUnmarshaler() component.CustomUnmarshaler {
+	return func(componentViperSection *viper.Viper, intoCfg interface{}) error {
+		return componentViperSection.UnmarshalExact(intoCfg)
+	}
+}
+
 // CreateTraceExporter creates a trace exporter based on this config.
 func (f *ExampleExporterFactory) CreateTraceExporter(_ *zap.Logger, _ configmodels.Exporter) (component.TraceExporterOld, error) {
 	return &ExampleExporterConsumer{}, nil

component/receiver.go

@@ -17,7 +17,6 @@ package component
 import (
 	"context"
 
-	"github.com/spf13/viper"
 	"go.uber.org/zap"
 
 	"go.opentelemetry.io/collector/config/configmodels"
@@ -68,21 +67,8 @@ type ReceiverFactoryBase interface {
 	// 'configcheck.ValidateConfig'. It is recommended to have such check in the
 	// tests of any implementation of the Factory interface.
 	CreateDefaultConfig() configmodels.Receiver
-
-	// CustomUnmarshaler returns a custom unmarshaler for the configuration or nil if
-	// there is no need for custom unmarshaling. This is typically used if viper.UnmarshalExact()
-	// is not sufficient to unmarshal correctly.
-	CustomUnmarshaler() CustomUnmarshaler
 }
 
-// CustomUnmarshaler is a function that un-marshals a viper data into a config struct
-// in a custom way.
-// componentViperSection *viper.Viper
-//   The config for this specific component. May be nil or empty if no config available.
-// intoCfg interface{}
-//   An empty interface wrapping a pointer to the config struct to unmarshal into.
-type CustomUnmarshaler func(componentViperSection *viper.Viper, intoCfg interface{}) error
-
 // ReceiverFactoryOld can create TraceReceiver and MetricsReceiver.
 type ReceiverFactoryOld interface {
 	ReceiverFactoryBase

component/receiver_test.go

@@ -34,11 +34,6 @@ func (f *TestReceiverFactory) Type() configmodels.Type {
 	return f.name
 }
 
-// CustomUnmarshaler returns nil because we don't need custom unmarshaling for this factory.
-func (f *TestReceiverFactory) CustomUnmarshaler() CustomUnmarshaler {
-	return nil
-}
-
 // CreateDefaultConfig creates the default configuration for the Receiver.
 func (f *TestReceiverFactory) CreateDefaultConfig() configmodels.Receiver {
 	return nil

config/config.go

@@ -83,6 +83,13 @@ const (
 	pipelinesKeyName = "pipelines"
 )
 
+type DeprecatedUnmarshaler interface {
+	// CustomUnmarshaler returns a custom unmarshaler for the configuration or nil if
+	// there is no need for custom unmarshaling. This is typically used if viper.UnmarshalExact()
+	// is not sufficient to unmarshal correctly.
+	CustomUnmarshaler() component.CustomUnmarshaler
+}
+
 // typeAndNameSeparator is the separator that is used between type and name in type/name composite keys.
 const typeAndNameSeparator = "/"
 
@@ -259,7 +266,7 @@ func loadExtensions(v *viper.Viper, factories map[configmodels.Type]component.Ex
 
 		// Now that the default config struct is created we can Unmarshal into it
 		// and it will apply user-defined config on top of the default.
-		if err := componentConfig.UnmarshalExact(extensionCfg); err != nil {
+		if err := unmarshal(factory, componentConfig, extensionCfg); err != nil {
 			return nil, errorUnmarshalError(extensionsKeyName, fullName, err)
 		}
 
@@ -309,16 +316,7 @@ func LoadReceiver(componentConfig *viper.Viper, typeStr configmodels.Type, fullN
 
 	// Now that the default config struct is created we can Unmarshal into it
 	// and it will apply user-defined config on top of the default.
-	customUnmarshaler := factory.CustomUnmarshaler()
-	var err error
-	if customUnmarshaler != nil {
-		// This configuration requires a custom unmarshaler, use it.
-		err = customUnmarshaler(componentConfig, receiverCfg)
-	} else {
-		err = componentConfig.UnmarshalExact(receiverCfg)
-	}
-
-	if err != nil {
+	if err := unmarshal(factory, componentConfig, receiverCfg); err != nil {
 		return nil, errorUnmarshalError(receiversKeyName, fullName, err)
 	}
 
@@ -401,7 +399,7 @@ func loadExporters(v *viper.Viper, factories map[configmodels.Type]component.Exp
 
 		// Now that the default config struct is created we can Unmarshal into it
 		// and it will apply user-defined config on top of the default.
-		if err := componentConfig.UnmarshalExact(exporterCfg); err != nil {
+		if err := unmarshal(factory, componentConfig, exporterCfg); err != nil {
 			return nil, errorUnmarshalError(exportersKeyName, fullName, err)
 		}
 
@@ -450,7 +448,7 @@ func loadProcessors(v *viper.Viper, factories map[configmodels.Type]component.Pr
 
 		// Now that the default config struct is created we can Unmarshal into it
 		// and it will apply user-defined config on top of the default.
-		if err := componentConfig.UnmarshalExact(processorCfg); err != nil {
+		if err := unmarshal(factory, componentConfig, processorCfg); err != nil {
 			return nil, errorUnmarshalError(processorsKeyName, fullName, err)
 		}
 
@@ -722,6 +720,22 @@ func expandEnv(s string) string {
 	})
 }
 
+func unmarshal(factory component.Factory, componentViperSection *viper.Viper, intoCfg interface{}) error {
+	customUnmarshaler := func(componentViperSection *viper.Viper, intoCfg interface{}) error {
+		return componentViperSection.UnmarshalExact(intoCfg)
+	}
+
+	if du, ok := factory.(DeprecatedUnmarshaler); ok && du.CustomUnmarshaler() != nil {
+		customUnmarshaler = du.CustomUnmarshaler()
+	}
+
+	if fu, ok := factory.(component.FactoryUnmarshaler); ok {
+		customUnmarshaler = fu.Unmarshal
+	}
+
+	return customUnmarshaler(componentViperSection, intoCfg)
+}
+
 // Copied from the Viper but changed to use the same delimiter.
 // See https://github.com/spf13/viper/issues/871
 func ViperSub(v *viper.Viper, key string) *viper.Viper {

config/config_test.go

@@ -421,8 +421,10 @@ func TestDecodeConfig_MultiProto(t *testing.T) {
 
 	assert.Equal(t,
 		&componenttest.MultiProtoReceiver{
-			TypeVal: "multireceiver",
-			NameVal: "multireceiver",
+			ReceiverSettings: configmodels.ReceiverSettings{
+				TypeVal: "multireceiver",
+				NameVal: "multireceiver",
+			},
 			Protocols: map[string]componenttest.MultiProtoReceiverOneCfg{
 				"http": {
 					Endpoint:     "example.com:8888",
@@ -439,8 +441,10 @@ func TestDecodeConfig_MultiProto(t *testing.T) {
 
 	assert.Equal(t,
 		&componenttest.MultiProtoReceiver{
-			TypeVal: "multireceiver",
-			NameVal: "multireceiver/myreceiver",
+			ReceiverSettings: configmodels.ReceiverSettings{
+				TypeVal: "multireceiver",
+				NameVal: "multireceiver/myreceiver",
+			},
 			Protocols: map[string]componenttest.MultiProtoReceiverOneCfg{
 				"http": {
 					Endpoint:     "localhost:12345",

exporter/exporterhelper/factory.go

@@ -17,6 +17,8 @@ package exporterhelper
 import (
 	"context"
 
+	"github.com/spf13/viper"
+
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/configerror"
 	"go.opentelemetry.io/collector/config/configmodels"
@@ -40,6 +42,7 @@ type CreateLogsExporter func(context.Context, component.ExporterCreateParams, co
 // factory is the factory for Jaeger gRPC exporter.
 type factory struct {
 	cfgType               configmodels.Type
+	customUnmarshaler     component.CustomUnmarshaler
 	createDefaultConfig   CreateDefaultConfig
 	createTraceExporter   CreateTraceExporter
 	createMetricsExporter CreateMetricsExporter
@@ -69,6 +72,13 @@ func WithLogs(createLogsExporter CreateLogsExporter) FactoryOption {
 	}
 }
 
+// WithCustomUnmarshaler overrides the default "not available" CustomUnmarshaler.
+func WithCustomUnmarshaler(customUnmarshaler component.CustomUnmarshaler) FactoryOption {
+	return func(o *factory) {
+		o.customUnmarshaler = customUnmarshaler
+	}
+}
+
 // NewFactory returns a component.ExporterFactory that only supports all types.
 func NewFactory(
 	cfgType configmodels.Type,
@@ -81,7 +91,13 @@ func NewFactory(
 	for _, opt := range options {
 		opt(f)
 	}
-	return f
+	var ret component.ExporterFactory
+	if f.customUnmarshaler != nil {
+		ret = &factoryWithUnmarshaler{f}
+	} else {
+		ret = f
+	}
+	return ret
 }
 
 // Type gets the type of the Exporter config created by this factory.
@@ -127,3 +143,15 @@ func (f *factory) CreateLogsExporter(
 	}
 	return nil, configerror.ErrDataTypeIsNotSupported
 }
+
+var _ component.FactoryUnmarshaler = (*factoryWithUnmarshaler)(nil)
+
+type factoryWithUnmarshaler struct {
+	*factory
+}
+
+// CustomUnmarshaler returns a custom unmarshaler for the configuration or nil if
+// there is no need for custom unmarshaling.
+func (f *factoryWithUnmarshaler) Unmarshal(componentViperSection *viper.Viper, intoCfg interface{}) error {
+	return f.customUnmarshaler(componentViperSection, intoCfg)
+}

exporter/exporterhelper/factory_test.go

@@ -16,8 +16,10 @@ package exporterhelper
 
 import (
 	"context"
+	"errors"
 	"testing"
 
+	"github.com/spf13/viper"
 	"github.com/stretchr/testify/assert"
 
 	"go.opentelemetry.io/collector/component"
@@ -44,6 +46,8 @@ func TestNewFactory(t *testing.T) {
 		defaultConfig)
 	assert.EqualValues(t, typeStr, factory.Type())
 	assert.EqualValues(t, defaultCfg, factory.CreateDefaultConfig())
+	_, ok := factory.(component.FactoryUnmarshaler)
+	assert.False(t, ok)
 	_, err := factory.CreateTraceExporter(context.Background(), component.ExporterCreateParams{}, defaultCfg)
 	assert.Equal(t, configerror.ErrDataTypeIsNotSupported, err)
 	_, err = factory.CreateMetricsExporter(context.Background(), component.ExporterCreateParams{}, defaultCfg)
@@ -59,10 +63,15 @@ func TestNewFactory_WithConstructors(t *testing.T) {
 		defaultConfig,
 		WithTraces(createTraceExporter),
 		WithMetrics(createMetricsExporter),
-		WithLogs(createLogsExporter))
+		WithLogs(createLogsExporter),
+		WithCustomUnmarshaler(customUnmarshaler))
 	assert.EqualValues(t, typeStr, factory.Type())
 	assert.EqualValues(t, defaultCfg, factory.CreateDefaultConfig())
 
+	fu, ok := factory.(component.FactoryUnmarshaler)
+	assert.True(t, ok)
+	assert.Equal(t, errors.New("my error"), fu.Unmarshal(nil, nil))
+
 	te, err := factory.CreateTraceExporter(context.Background(), component.ExporterCreateParams{}, defaultCfg)
 	assert.NoError(t, err)
 	assert.Same(t, nopTracesExporter, te)
@@ -92,3 +101,7 @@ func createMetricsExporter(context.Context, component.ExporterCreateParams, conf
 func createLogsExporter(context.Context, component.ExporterCreateParams, configmodels.Exporter) (component.LogsExporter, error) {
 	return nopLogsExporter, nil
 }
+
+func customUnmarshaler(*viper.Viper, interface{}) error {
+	return errors.New("my error")
+}