opentelemetry-collector/otelcol/configprovider.go

96 lines
3.1 KiB
Go

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0
package otelcol // import "go.opentelemetry.io/collector/otelcol"
import (
"context"
"fmt"
"go.opentelemetry.io/collector/confmap"
)
// ConfigProvider provides the service configuration.
//
// The typical usage is the following:
//
// cfgProvider.Get(...)
// cfgProvider.Watch() // wait for an event.
// cfgProvider.Get(...)
// cfgProvider.Watch() // wait for an event.
// // repeat Get/Watch cycle until it is time to shut down the Collector process.
// cfgProvider.Shutdown()
type ConfigProvider struct {
mapResolver *confmap.Resolver
}
// ConfigProviderSettings are the settings to configure the behavior of the ConfigProvider.
type ConfigProviderSettings struct {
// ResolverSettings are the settings to configure the behavior of the confmap.Resolver.
ResolverSettings confmap.ResolverSettings
// prevent unkeyed literal initialization
_ struct{}
}
// NewConfigProvider returns a new ConfigProvider that provides the service configuration:
// * Initially it resolves the "configuration map":
// - Retrieve the confmap.Conf by merging all retrieved maps from the given `locations` in order.
// - Then applies all the confmap.Converter in the given order.
//
// * Then unmarshalls the confmap.Conf into the service Config.
func NewConfigProvider(set ConfigProviderSettings) (*ConfigProvider, error) {
mr, err := confmap.NewResolver(set.ResolverSettings)
if err != nil {
return nil, err
}
return &ConfigProvider{
mapResolver: mr,
}, nil
}
// Get returns the service configuration, or error otherwise.
//
// Should never be called concurrently with itself, Watch or Shutdown.
func (cm *ConfigProvider) Get(ctx context.Context, factories Factories) (*Config, error) {
conf, err := cm.mapResolver.Resolve(ctx)
if err != nil {
return nil, fmt.Errorf("cannot resolve the configuration: %w", err)
}
var cfg *configSettings
if cfg, err = unmarshal(conf, factories); err != nil {
return nil, fmt.Errorf("cannot unmarshal the configuration: %w", err)
}
return &Config{
Receivers: cfg.Receivers.Configs(),
Processors: cfg.Processors.Configs(),
Exporters: cfg.Exporters.Configs(),
Connectors: cfg.Connectors.Configs(),
Extensions: cfg.Extensions.Configs(),
Service: cfg.Service,
}, nil
}
// Watch blocks until any configuration change was detected or an unrecoverable error
// happened during monitoring the configuration changes.
//
// Error is nil if the configuration is changed and needs to be re-fetched. Any non-nil
// error indicates that there was a problem with watching the config changes.
//
// Should never be called concurrently with itself or Get.
func (cm *ConfigProvider) Watch() <-chan error {
return cm.mapResolver.Watch()
}
// Shutdown signals that the provider is no longer in use and the that should close
// and release any resources that it may have created.
//
// This function must terminate the Watch channel.
//
// Should never be called concurrently with itself or Get.
func (cm *ConfigProvider) Shutdown(ctx context.Context) error {
return cm.mapResolver.Shutdown(ctx)
}