opentelemetry-collector/component/extension.go

131 lines
5.0 KiB
Go

// 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 component // import "go.opentelemetry.io/collector/component"
import (
"context"
"go.opentelemetry.io/collector/confmap"
)
// ExtensionConfig is the configuration of a component.Extension. Specific extensions must implement
// this interface and must embed config.ExtensionSettings struct or a struct that extends it.
type ExtensionConfig interface {
identifiable
validatable
privateConfigExtension()
}
// UnmarshalExtensionConfig helper function to unmarshal an ExtensionConfig.
// It checks if the config implements confmap.Unmarshaler and uses that if available,
// otherwise uses Map.UnmarshalExact, erroring if a field is nonexistent.
func UnmarshalExtensionConfig(conf *confmap.Conf, cfg ExtensionConfig) error {
return unmarshal(conf, cfg)
}
// Extension is the interface for objects hosted by the OpenTelemetry Collector that
// don't participate directly on data pipelines but provide some functionality
// to the service, examples: health check endpoint, z-pages, etc.
type Extension interface {
Component
}
// PipelineWatcher is an extra interface for Extension hosted by the OpenTelemetry
// Collector that is to be implemented by extensions interested in changes to pipeline
// states. Typically this will be used by extensions that change their behavior if data is
// being ingested or not, e.g.: a k8s readiness probe.
type PipelineWatcher interface {
// Ready notifies the Extension that all pipelines were built and the
// receivers were started, i.e.: the service is ready to receive data
// (note that it may already have received data when this method is called).
Ready() error
// NotReady notifies the Extension that all receivers are about to be stopped,
// i.e.: pipeline receivers will not accept new data.
// This is sent before receivers are stopped, so the Extension can take any
// appropriate actions before that happens.
NotReady() error
}
// ExtensionCreateSettings is passed to ExtensionFactory.Create* functions.
type ExtensionCreateSettings struct {
TelemetrySettings
// BuildInfo can be used by components for informational purposes
BuildInfo BuildInfo
}
// ExtensionCreateDefaultConfigFunc is the equivalent of ExtensionFactory.CreateDefaultConfig()
type ExtensionCreateDefaultConfigFunc func() ExtensionConfig
// CreateDefaultConfig implements ExtensionFactory.CreateDefaultConfig()
func (f ExtensionCreateDefaultConfigFunc) CreateDefaultConfig() ExtensionConfig {
return f()
}
// CreateExtensionFunc is the equivalent of ExtensionFactory.CreateExtension()
type CreateExtensionFunc func(context.Context, ExtensionCreateSettings, ExtensionConfig) (Extension, error)
// CreateExtension implements ExtensionFactory.CreateExtension.
func (f CreateExtensionFunc) CreateExtension(ctx context.Context, set ExtensionCreateSettings, cfg ExtensionConfig) (Extension, error) {
return f(ctx, set, cfg)
}
// ExtensionFactory is a factory for extensions to the service.
type ExtensionFactory interface {
Factory
// CreateDefaultConfig creates the default configuration for the Extension.
// This method can be called multiple times depending on the pipeline
// configuration and should not cause side-effects that prevent the creation
// of multiple instances of the Extension.
// The object returned by this method needs to pass the checks implemented by
// 'componenttest.CheckConfigStruct'. It is recommended to have these checks in the
// tests of any implementation of the Factory interface.
CreateDefaultConfig() ExtensionConfig
// CreateExtension creates an extension based on the given config.
CreateExtension(ctx context.Context, set ExtensionCreateSettings, cfg ExtensionConfig) (Extension, error)
// ExtensionStability gets the stability level of the Extension.
ExtensionStability() StabilityLevel
}
type extensionFactory struct {
baseFactory
ExtensionCreateDefaultConfigFunc
CreateExtensionFunc
extensionStability StabilityLevel
}
func (ef *extensionFactory) ExtensionStability() StabilityLevel {
return ef.extensionStability
}
// NewExtensionFactory returns a new ExtensionFactory based on this configuration.
func NewExtensionFactory(
cfgType Type,
createDefaultConfig ExtensionCreateDefaultConfigFunc,
createServiceExtension CreateExtensionFunc,
sl StabilityLevel) ExtensionFactory {
return &extensionFactory{
baseFactory: baseFactory{cfgType: cfgType},
ExtensionCreateDefaultConfigFunc: createDefaultConfig,
CreateExtensionFunc: createServiceExtension,
extensionStability: sl,
}
}