OpenTelemetry Collector を開発する
メトリクスを設計する
レシーバーによってキャプチャされるメトリクスを定義し、エクスポートするために、コレクターのために開発された mdatagen を使って、yaml で定義したメトリクスをコードに変換していきます。
---
# Type defines the name to reference the component
# in the configuration file
type: jenkins
# Status defines the component type and the stability level
status:
class: receiver
stability:
development: [metrics]
# Attributes are the expected fields reported
# with the exported values.
attributes:
job.name:
description: The name of the associated Jenkins job
type: string
job.status:
description: Shows if the job had passed, or failed
type: string
enum:
- failed
- success
- unknown
# Metrics defines all the pontentially exported values from this receiver.
metrics:
jenkins.jobs.count:
enabled: true
description: Provides a count of the total number of configured jobs
unit: "{Count}"
gauge:
value_type: int
jenkins.job.duration:
enabled: true
description: Show the duration of the job
unit: "s"
gauge:
value_type: int
attributes:
- job.name
- job.status
jenkins.job.commit_delta:
enabled: true
description: The calculation difference of the time job was finished minus commit timestamp
unit: "s"
gauge:
value_type: int
attributes:
- job.name
- job.status// To generate the additional code needed to capture metrics,
// the following command to be run from the shell:
// go generate -x ./...
//go:generate go run github.com/open-telemetry/opentelemetry-collector-contrib/cmd/mdatagen@v0.80.0 metadata.yaml
package jenkinscireceiver
// There is no code defined within this file.
次のセクションに進む前に、これらのファイルをプロジェクトフォルダ内に作成してください。
Factory の構築
Factory はソフトウェアデザインパターンの一種で、提供された Configuration を使って、動的にオブジェクト（この場合は jenkinscireceiver）を作成するものです。現実的な例では、携帯電話店に行って、あなたの正確な説明に合った携帯電話を求め、それを提供されるようなものです。
コマンド go generate -x ./... を実行すると、定義されたメトリクスをエクスポートするために必要なすべてのコードを含む新しいフォルダ jenkinscireceiver/internal/metadata が作成されます。生成されるコードは以下の通りです：
package jenkinscireceiver
import (
"errors"
"go.opentelemetry.io/collector/component"
"go.opentelemetry.io/collector/config/confighttp"
"go.opentelemetry.io/collector/receiver"
"go.opentelemetry.io/collector/receiver/scraperhelper"
"splunk.conf/workshop/example/jenkinscireceiver/internal/metadata"
)
func NewFactory() receiver.Factory {
return receiver.NewFactory(
metadata.Type,
newDefaultConfig,
receiver.WithMetrics(newMetricsReceiver, metadata.MetricsStability),
)
}
func newMetricsReceiver(_ context.Context, set receiver.CreateSettings, cfg component.Config, consumer consumer.Metrics) (receiver.Metrics, error) {
// Convert the configuration into the expected type
conf, ok := cfg.(*Config)
if !ok {
return nil, errors.New("can not convert config")
}
sc, err := newScraper(conf, set)
if err != nil {
return nil, err
}
return scraperhelper.NewScraperControllerReceiver(
&conf.ScraperControllerSettings,
set,
consumer,
scraperhelper.AddScraper(sc),
)
}package jenkinscireceiver
import (
"go.opentelemetry.io/collector/config/confighttp"
"go.opentelemetry.io/collector/receiver/scraperhelper"
"splunk.conf/workshop/example/jenkinscireceiver/internal/metadata"
)
type Config struct {
// HTTPClientSettings contains all the values
// that are commonly shared across all HTTP interactions
// performed by the collector.
confighttp.HTTPClientSettings `mapstructure:",squash"`
// ScraperControllerSettings will allow us to schedule
// how often to check for updates to builds.
scraperhelper.ScraperControllerSettings `mapstructure:",squash"`
// MetricsBuilderConfig contains all the metrics
// that can be configured.
metadata.MetricsBuilderConfig `mapstructure:",squash"`
}
func newDefaultConfig() component.Config {
return &Config{
ScraperControllerSettings: scraperhelper.NewDefaultScraperControllerSettings(metadata.Type),
HTTPClientSettings: confighttp.NewDefaultHTTPClientSettings(),
MetricsBuilderConfig: metadata.DefaultMetricsBuilderConfig(),
}
}package jenkinscireceiver
type scraper struct {}
func newScraper(cfg *Config, set receiver.CreateSettings) (scraperhelper.Scraper, error) {
// Create a our scraper with our values
s := scraper{
// To be filled in later
}
return scraperhelper.NewScraper(metadata.Type, s.scrape)
}
func (scraper) scrape(ctx context.Context) (pmetric.Metrics, error) {
// To be filled in
return pmetrics.NewMetrics(), nil
}---
dist:
name: otelcol
description: "Conf workshop collector"
output_path: ./dist
version: v0.0.0-experimental
extensions:
- gomod: github.com/open-telemetry/opentelemetry-collector-contrib/extension/basicauthextension v0.80.0
- gomod: github.com/open-telemetry/opentelemetry-collector-contrib/extension/healthcheckextension v0.80.0
receivers:
- gomod: go.opentelemetry.io/collector/receiver/otlpreceiver v0.80.0
- gomod: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/jaegerreceiver v0.80.0
- gomod: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/prometheusreceiver v0.80.0
- gomod: splunk.conf/workshop/example/jenkinscireceiver v0.0.0
path: ./jenkinscireceiver
processors:
- gomod: go.opentelemetry.io/collector/processor/batchprocessor v0.80.0
exporters:
- gomod: go.opentelemetry.io/collector/exporter/loggingexporter v0.80.0
- gomod: go.opentelemetry.io/collector/exporter/otlpexporter v0.80.0
- gomod: go.opentelemetry.io/collector/exporter/otlphttpexporter v0.80.0
# This replace is a go directive that allows for redefine
# where to fetch the code to use since the default would be from a remote project.
replaces:
- splunk.conf/workshop/example/jenkinscireceiver => ./jenkinscireceiver├── build-config.yaml
└── jenkinscireceiver
├── go.mod
├── config.go
├── factory.go
├── scraper.go
└── internal
└── metadataこれらのファイルがプロジェクトに作成されたら、go mod tidy を実行します。すると、すべての依存ライブラリが取得され、go.mod が更新されます。