opentelemetry-collector/scraper/factory.go

119 lines
3.4 KiB
Go

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0
package scraper // import "go.opentelemetry.io/collector/scraper"
import (
"context"
"fmt"
"go.opentelemetry.io/collector/component"
"go.opentelemetry.io/collector/pipeline"
)
// Settings configures scraper creators.
type Settings struct {
// ID returns the ID of the component that will be created.
ID component.ID
component.TelemetrySettings
// BuildInfo can be used by components for informational purposes.
BuildInfo component.BuildInfo
}
// Factory is factory interface for scrapers.
//
// This interface cannot be directly implemented. Implementations must
// use the NewFactory to implement it.
type Factory interface {
component.Factory
// CreateMetrics creates a Metrics scraper based on this config.
// If the scraper type does not support metrics,
// this function returns the error [pipeline.ErrSignalNotSupported].
// Implementers can assume `next` is never nil.
CreateMetrics(ctx context.Context, set Settings, cfg component.Config) (Metrics, error)
// MetricsStability gets the stability level of the Metrics scraper.
MetricsStability() component.StabilityLevel
unexportedFactoryFunc()
}
// FactoryOption apply changes to Options.
type FactoryOption interface {
// applyOption applies the option.
applyOption(o *factory)
}
var _ FactoryOption = (*factoryOptionFunc)(nil)
// factoryOptionFunc is a FactoryOption created through a function.
type factoryOptionFunc func(*factory)
func (f factoryOptionFunc) applyOption(o *factory) {
f(o)
}
type factory struct {
cfgType component.Type
component.CreateDefaultConfigFunc
CreateMetricsFunc
metricsStabilityLevel component.StabilityLevel
}
func (f *factory) Type() component.Type {
return f.cfgType
}
func (f *factory) unexportedFactoryFunc() {}
func (f *factory) MetricsStability() component.StabilityLevel {
return f.metricsStabilityLevel
}
// CreateMetricsFunc is the equivalent of Factory.CreateMetrics().
type CreateMetricsFunc func(context.Context, Settings, component.Config) (Metrics, error)
// CreateMetrics implements Factory.CreateMetrics.
func (f CreateMetricsFunc) CreateMetrics(ctx context.Context, set Settings, cfg component.Config) (Metrics, error) {
if f == nil {
return nil, pipeline.ErrSignalNotSupported
}
return f(ctx, set, cfg)
}
// WithMetrics overrides the default "error not supported" implementation for CreateMetrics and the default "undefined" stability level.
func WithMetrics(createMetrics CreateMetricsFunc, sl component.StabilityLevel) FactoryOption {
return factoryOptionFunc(func(o *factory) {
o.metricsStabilityLevel = sl
o.CreateMetricsFunc = createMetrics
})
}
// NewFactory returns a Factory.
func NewFactory(cfgType component.Type, createDefaultConfig component.CreateDefaultConfigFunc, options ...FactoryOption) Factory {
f := &factory{
cfgType: cfgType,
CreateDefaultConfigFunc: createDefaultConfig,
}
for _, opt := range options {
opt.applyOption(f)
}
return f
}
// MakeFactoryMap takes a list of receiver factories and returns a map with factory type as keys.
// It returns a non-nil error when there are factories with duplicate type.
func MakeFactoryMap(factories ...Factory) (map[component.Type]Factory, error) {
fMap := map[component.Type]Factory{}
for _, f := range factories {
if _, ok := fMap[f.Type()]; ok {
return fMap, fmt.Errorf("duplicate scraper factory %q", f.Type())
}
fMap[f.Type()] = f
}
return fMap, nil
}