Create configload.Parser struct to abstract away from Viper

component/component.go

@@ -18,7 +18,7 @@ import (
 	"context"
 
 	"github.com/spf13/viper"
-
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 )
 
@@ -67,18 +67,25 @@ type Factory interface {
 // ConfigUnmarshaler interface is an optional interface that if implemented by a Factory,
 // the configuration loading system will use to unmarshal the config.
 type ConfigUnmarshaler 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.
+	// Unmarshal is a function that loads data into a config struct in a custom way.
+	// componentSection *configload.Loader
+	//   The loader 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
+	Unmarshal(componentSection *configload.Loader, intoCfg interface{}) error
 }
 
-// CustomUnmarshaler is a function that un-marshals a viper data into a config struct
+// CustomUnmarshaler is a function that loads 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.
+// componentSection *configload.Loader
+//   The loader 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
+type CustomUnmarshaler func(componentSection *configload.Loader, intoCfg interface{}) error
+
+// ToCustomUnmarshaler creates a custom unmarshaler from a Viper unmarshaler.
+func ToCustomUnmarshaler(viperUnmarshaler func(*viper.Viper, interface{}) error) CustomUnmarshaler {
+	return func(componentSection *configload.Loader, intoCfg interface{}) error {
+		return viperUnmarshaler(componentSection.Viper(), intoCfg)
+	}
+}

config/config.go

@@ -28,6 +28,7 @@ import (
 	"github.com/spf13/viper"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 )
 
@@ -44,11 +45,6 @@ const (
 	errUnmarshalTopLevelStructureError
 )
 
-const (
-	// ViperDelimiter is used as the default key delimiter in the default viper instance
-	ViperDelimiter = "::"
-)
-
 type configError struct {
 	msg  string          // human readable error message.
 	code configErrorCode // internal error code.
@@ -98,12 +94,6 @@ type pipelineSettings struct {
 // typeAndNameSeparator is the separator that is used between type and name in type/name composite keys.
 const typeAndNameSeparator = "/"
 
-// Creates a new Viper instance with a different key-delimitor "::" instead of the
-// default ".". This way configs can have keys that contain ".".
-func NewViper() *viper.Viper {
-	return viper.NewWithOptions(viper.KeyDelimiter(ViperDelimiter))
-}
-
 // Load loads a Config from Viper.
 // After loading the config, need to check if it is valid by calling `ValidateConfig`.
 func Load(
@@ -262,7 +252,7 @@ func loadExtensions(exts map[string]interface{}, factories map[configmodels.Type
 		// 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.
 		unm := unmarshaler(factory)
-		if err := unm(componentConfig, extensionCfg); err != nil {
+		if err := unm(configload.FromViper(componentConfig), extensionCfg); err != nil {
 			return nil, errorUnmarshalError(extensionsKeyName, fullName, err)
 		}
 
@@ -298,7 +288,7 @@ 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.
 	unm := unmarshaler(factory)
-	if err := unm(componentConfig, receiverCfg); err != nil {
+	if err := unm(configload.FromViper(componentConfig), receiverCfg); err != nil {
 		return nil, errorUnmarshalError(receiversKeyName, fullName, err)
 	}
 
@@ -371,7 +361,7 @@ func loadExporters(exps map[string]interface{}, factories map[configmodels.Type]
 		// 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.
 		unm := unmarshaler(factory)
-		if err := unm(componentConfig, exporterCfg); err != nil {
+		if err := unm(configload.FromViper(componentConfig), exporterCfg); err != nil {
 			return nil, errorUnmarshalError(exportersKeyName, fullName, err)
 		}
 
@@ -414,7 +404,7 @@ func loadProcessors(procs map[string]interface{}, factories map[configmodels.Typ
 		// 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.
 		unm := unmarshaler(factory)
-		if err := unm(componentConfig, processorCfg); err != nil {
+		if err := unm(configload.FromViper(componentConfig), processorCfg); err != nil {
 			return nil, errorUnmarshalError(processorsKeyName, fullName, err)
 		}
 
@@ -556,8 +546,8 @@ func unmarshaler(factory component.Factory) component.CustomUnmarshaler {
 	return defaultUnmarshaler
 }
 
-func defaultUnmarshaler(componentViperSection *viper.Viper, intoCfg interface{}) error {
-	return componentViperSection.UnmarshalExact(intoCfg)
+func defaultUnmarshaler(componentSection *configload.Loader, intoCfg interface{}) error {
+	return componentSection.UnmarshalExact(intoCfg)
 }
 
 // Copied from the Viper but changed to use the same delimiter
@@ -566,11 +556,11 @@ func defaultUnmarshaler(componentViperSection *viper.Viper, intoCfg interface{})
 func ViperSubExact(v *viper.Viper, key string) (*viper.Viper, error) {
 	data := v.Get(key)
 	if data == nil {
-		return NewViper(), nil
+		return configload.NewViper(), nil
 	}
 
 	if reflect.TypeOf(data).Kind() == reflect.Map {
-		subv := NewViper()
+		subv := configload.NewViper()
 		// Cannot return error because the subv is empty.
 		_ = subv.MergeConfigMap(cast.ToStringMap(data))
 		return subv, nil
@@ -582,7 +572,7 @@ func ViperSubExact(v *viper.Viper, key string) (*viper.Viper, error) {
 }
 
 func viperFromStringMap(data map[string]interface{}) *viper.Viper {
-	v := NewViper()
+	v := configload.NewViper()
 	// Cannot return error because the subv is empty.
 	_ = v.MergeConfigMap(cast.ToStringMap(data))
 	return v

config/config_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 	"go.opentelemetry.io/collector/config/confignet"
 	"go.opentelemetry.io/collector/internal/testcomponents"
@@ -495,7 +496,7 @@ func TestLoadEmptyAllSections(t *testing.T) {
 
 func loadConfigFile(t *testing.T, fileName string, factories component.Factories) (*configmodels.Config, error) {
 	// Read yaml config from file
-	v := NewViper()
+	v := configload.NewViper()
 	v.SetConfigFile(fileName)
 	require.NoErrorf(t, v.ReadInConfig(), "unable to read the file %v", fileName)
 

config/configload/configload.go

@@ -0,0 +1,64 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//       http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// package configload implements the configuration Loader struct.
+package configload
+
+import (
+	"github.com/spf13/cast"
+	"github.com/spf13/viper"
+)
+
+const (
+	// ViperDelimiter is used as the default key delimiter in the default viper instance
+	ViperDelimiter = "::"
+)
+
+// Creates a new Viper instance with a different key-delimitor "::" instead of the
+// default ".". This way configs can have keys that contain ".".
+func NewViper() *viper.Viper {
+	return viper.NewWithOptions(viper.KeyDelimiter(ViperDelimiter))
+}
+
+// NewLoader creates a new Loader instanceg
+func NewLoader() *Loader {
+	return &Loader{
+		v: NewViper(),
+	}
+}
+
+// FromViper creates a Loader from a Viper instance
+func FromViper(v *viper.Viper) *Loader {
+	return &Loader{v: v}
+}
+
+// Loader loads configuration
+type Loader struct {
+	v *viper.Viper
+}
+
+// Viper returns the underlying Viper instance
+func (l *Loader) Viper() *viper.Viper {
+	return l.v
+}
+
+// UnmarshalExact unmarshals the config into a struct, erroring if a field is nonexistent
+func (l *Loader) UnmarshalExact(intoCfg interface{}) error {
+	return l.v.UnmarshalExact(intoCfg)
+}
+
+// ToStringMap creates a map[string]interface{} from a ConfigLoader
+func (l *Loader) ToStringMap() map[string]interface{} {
+	return cast.ToStringMap(l.v)
+}

config/configtest/configtest.go

@@ -22,6 +22,7 @@ import (
 
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 )
 
@@ -30,7 +31,7 @@ import (
 // Example usage for testing can be found in configtest_test.go
 func NewViperFromYamlFile(t *testing.T, fileName string) *viper.Viper {
 	// Read yaml config from file
-	v := config.NewViper()
+	v := configload.NewViper()
 	v.SetConfigFile(fileName)
 	require.NoErrorf(t, v.ReadInConfig(), "unable to read the file %v", fileName)
 

exporter/exporterhelper/factory.go

@@ -17,10 +17,9 @@ package exporterhelper
 import (
 	"context"
 
-	"github.com/spf13/viper"
-
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/configerror"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 )
 
@@ -148,6 +147,6 @@ type factoryWithUnmarshaler struct {
 }
 
 // Unmarshal un-marshals the config using the provided custom unmarshaler.
-func (f *factoryWithUnmarshaler) Unmarshal(componentViperSection *viper.Viper, intoCfg interface{}) error {
-	return f.customUnmarshaler(componentViperSection, intoCfg)
+func (f *factoryWithUnmarshaler) Unmarshal(componentSection *configload.Loader, intoCfg interface{}) error {
+	return f.customUnmarshaler(componentSection, intoCfg)
 }

exporter/exporterhelper/factory_test.go

@@ -19,12 +19,12 @@ import (
 	"errors"
 	"testing"
 
-	"github.com/spf13/viper"
 	"github.com/stretchr/testify/assert"
 	"go.uber.org/zap"
 
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/configerror"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 	"go.opentelemetry.io/collector/consumer/pdata"
 )
@@ -107,6 +107,6 @@ func createLogsExporter(context.Context, component.ExporterCreateParams, configm
 	return nopLogsExporter, nil
 }
 
-func customUnmarshaler(*viper.Viper, interface{}) error {
+func customUnmarshaler(*configload.Loader, interface{}) error {
 	return errors.New("my error")
 }

extension/extensionhelper/factory.go

@@ -17,9 +17,8 @@ package extensionhelper
 import (
 	"context"
 
-	"github.com/spf13/viper"
-
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 )
 
@@ -94,6 +93,6 @@ type factoryWithUnmarshaler struct {
 }
 
 // Unmarshal un-marshals the config using the provided custom unmarshaler.
-func (f *factoryWithUnmarshaler) Unmarshal(componentViperSection *viper.Viper, intoCfg interface{}) error {
-	return f.customUnmarshaler(componentViperSection, intoCfg)
+func (f *factoryWithUnmarshaler) Unmarshal(componentSection *configload.Loader, intoCfg interface{}) error {
+	return f.customUnmarshaler(componentSection, intoCfg)
 }

extension/extensionhelper/factory_test.go

@@ -19,10 +19,10 @@ import (
 	"errors"
 	"testing"
 
-	"github.com/spf13/viper"
 	"github.com/stretchr/testify/assert"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 )
 
@@ -74,7 +74,7 @@ func createExtension(context.Context, component.ExtensionCreateParams, configmod
 	return nopExtensionInstance, nil
 }
 
-func customUnmarshaler(*viper.Viper, interface{}) error {
+func customUnmarshaler(*configload.Loader, interface{}) error {
 	return errors.New("my error")
 }
 

internal/testcomponents/example_exporter.go

@@ -17,9 +17,8 @@ package testcomponents
 import (
 	"context"
 
-	"github.com/spf13/viper"
-
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 	"go.opentelemetry.io/collector/consumer/pdata"
 	"go.opentelemetry.io/collector/exporter/exporterhelper"
@@ -59,8 +58,8 @@ func createExporterDefaultConfig() configmodels.Exporter {
 	}
 }
 
-func customUnmarshal(componentViperSection *viper.Viper, intoCfg interface{}) error {
-	return componentViperSection.UnmarshalExact(intoCfg)
+func customUnmarshal(componentSection *configload.Loader, intoCfg interface{}) error {
+	return componentSection.UnmarshalExact(intoCfg)
 }
 
 func createTracesExporter(

processor/processorhelper/factory.go

@@ -17,10 +17,9 @@ package processorhelper
 import (
 	"context"
 
-	"github.com/spf13/viper"
-
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/configerror"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 	"go.opentelemetry.io/collector/consumer"
 )
@@ -144,6 +143,6 @@ type factoryWithUnmarshaler struct {
 }
 
 // Unmarshal un-marshals the config using the provided custom unmarshaler.
-func (f *factoryWithUnmarshaler) Unmarshal(componentViperSection *viper.Viper, intoCfg interface{}) error {
-	return f.customUnmarshaler(componentViperSection, intoCfg)
+func (f *factoryWithUnmarshaler) Unmarshal(componentSection *configload.Loader, intoCfg interface{}) error {
+	return f.customUnmarshaler(componentSection, intoCfg)
 }

processor/processorhelper/factory_test.go

@@ -19,10 +19,10 @@ import (
 	"errors"
 	"testing"
 
-	"github.com/spf13/viper"
 	"github.com/stretchr/testify/assert"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configload"
 	"go.opentelemetry.io/collector/config/configmodels"
 	"go.opentelemetry.io/collector/consumer"
 )
@@ -91,6 +91,6 @@ func createLogsProcessor(context.Context, component.ProcessorCreateParams, confi
 	return nil, nil
 }
 
-func customUnmarshaler(*viper.Viper, interface{}) error {
+func customUnmarshaler(*configload.Loader, interface{}) error {
 	return errors.New("my error")
 }