Change scraperhelper to follow the recommended append model for pdata (…

…#4202) Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>
open-telemetry · Oct 15, 2021 · bd87fb6 · bd87fb6
1 parent 028fc46
commit bd87fb6
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Showing 3 changed files with 58 additions and 209 deletions.
diff --git a/receiver/scraperhelper/scraper.go b/receiver/scraperhelper/scraper.go
@@ -16,45 +16,38 @@ package scraperhelper // import "go.opentelemetry.io/collector/receiver/scraperh
 
 import (
 	"context"
+	"errors"
 
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/component/componenthelper"
 	"go.opentelemetry.io/collector/config"
 	"go.opentelemetry.io/collector/model/pdata"
-	"go.opentelemetry.io/collector/obsreport"
-	"go.opentelemetry.io/collector/receiver/scrapererror"
 )
 
-// ScrapeMetrics scrapes metrics.
-type ScrapeMetrics func(context.Context) (pdata.MetricSlice, error)
+var errNilFunc = errors.New("nil scrape func")
 
-// ScrapeResourceMetrics scrapes resource metrics.
-type ScrapeResourceMetrics func(context.Context) (pdata.ResourceMetricsSlice, error)
+// ScrapeFunc scrapes metrics.
+type ScrapeFunc func(context.Context) (pdata.Metrics, error)
 
-type baseSettings struct {
-	componentOptions []componenthelper.Option
+func (sf ScrapeFunc) Scrape(ctx context.Context) (pdata.Metrics, error) {
+	return sf(ctx)
 }
 
-// ScraperOption apply changes to internal options.
-type ScraperOption func(*baseSettings)
-
 // Scraper is the base interface for scrapers.
 type Scraper interface {
 	component.Component
 
 	// ID returns the scraper id.
 	ID() config.ComponentID
-	Scrape(context.Context, config.ComponentID, component.ReceiverCreateSettings) (pdata.Metrics, error)
+	Scrape(context.Context) (pdata.Metrics, error)
 }
 
-type baseScraper struct {
-	component.Component
-	id config.ComponentID
+type baseSettings struct {
+	componentOptions []componenthelper.Option
 }
 
-func (b baseScraper) ID() config.ComponentID {
-	return b.id
-}
+// ScraperOption apply changes to internal options.
+type ScraperOption func(*baseSettings)
 
 // WithStart sets the function that will be called on startup.
 func WithStart(start componenthelper.StartFunc) ScraperOption {
@@ -70,104 +63,34 @@ func WithShutdown(shutdown componenthelper.ShutdownFunc) ScraperOption {
 	}
 }
 
-type metricsScraper struct {
-	baseScraper
-	ScrapeMetrics
-}
-
-var _ Scraper = (*metricsScraper)(nil)
-
-// NewMetricsScraper creates a Scraper that calls Scrape at the specified
-// collection interval, reports observability information, and passes the
-// scraped metrics to the next consumer.
-func NewMetricsScraper(
-	name string,
-	scrape ScrapeMetrics,
-	options ...ScraperOption,
-) Scraper {
-	set := &baseSettings{}
-	for _, op := range options {
-		op(set)
-	}
-
-	ms := &metricsScraper{
-		baseScraper: baseScraper{
-			Component: componenthelper.New(set.componentOptions...),
-			id:        config.NewComponentID(config.Type(name)),
-		},
-		ScrapeMetrics: scrape,
-	}
+var _ Scraper = (*baseScraper)(nil)
 
-	return ms
-}
-
-func (ms metricsScraper) Scrape(ctx context.Context, receiverID config.ComponentID, set component.ReceiverCreateSettings) (pdata.Metrics, error) {
-	scrp := obsreport.NewScraper(obsreport.ScraperSettings{
-		ReceiverID:             receiverID,
-		Scraper:                ms.ID(),
-		ReceiverCreateSettings: set,
-	})
-	ctx = scrp.StartMetricsOp(ctx)
-	metrics, err := ms.ScrapeMetrics(ctx)
-	count := 0
-	md := pdata.Metrics{}
-	if err == nil || scrapererror.IsPartialScrapeError(err) {
-		md = pdata.NewMetrics()
-		metrics.MoveAndAppendTo(md.ResourceMetrics().AppendEmpty().InstrumentationLibraryMetrics().AppendEmpty().Metrics())
-		count = md.MetricCount()
-	}
-	scrp.EndMetricsOp(ctx, count, err)
-	return md, err
+type baseScraper struct {
+	component.Component
+	ScrapeFunc
+	id config.ComponentID
 }
 
-type resourceMetricsScraper struct {
-	baseScraper
-	ScrapeResourceMetrics
+func (b *baseScraper) ID() config.ComponentID {
+	return b.id
 }
 
-var _ Scraper = (*resourceMetricsScraper)(nil)
-
-// NewResourceMetricsScraper creates a Scraper that calls Scrape at the
-// specified collection interval, reports observability information, and
-// passes the scraped resource metrics to the next consumer.
-func NewResourceMetricsScraper(
-	id config.ComponentID,
-	scrape ScrapeResourceMetrics,
-	options ...ScraperOption,
-) Scraper {
+// NewScraper creates a Scraper that calls Scrape at the specified collection interval,
+// reports observability information, and passes the scraped metrics to the next consumer.
+func NewScraper(name string, scrape ScrapeFunc, options ...ScraperOption) (Scraper, error) {
+	if scrape == nil {
+		return nil, errNilFunc
+	}
 	set := &baseSettings{}
 	for _, op := range options {
 		op(set)
 	}
 
-	rms := &resourceMetricsScraper{
-		baseScraper: baseScraper{
-			Component: componenthelper.New(set.componentOptions...),
-			id:        id,
-		},
-		ScrapeResourceMetrics: scrape,
-	}
-
-	return rms
-}
-
-func (rms resourceMetricsScraper) Scrape(ctx context.Context, receiverID config.ComponentID, set component.ReceiverCreateSettings) (pdata.Metrics, error) {
-	scrp := obsreport.NewScraper(obsreport.ScraperSettings{
-		ReceiverID:             receiverID,
-		Scraper:                rms.ID(),
-		ReceiverCreateSettings: set,
-	})
-	ctx = scrp.StartMetricsOp(ctx)
-	resourceMetrics, err := rms.ScrapeResourceMetrics(ctx)
-
-	count := 0
-	md := pdata.Metrics{}
-	if err == nil || scrapererror.IsPartialScrapeError(err) {
-		md = pdata.NewMetrics()
-		resourceMetrics.MoveAndAppendTo(md.ResourceMetrics())
-		count = md.MetricCount()
+	ms := &baseScraper{
+		Component:  componenthelper.New(set.componentOptions...),
+		ScrapeFunc: scrape,
+		id:         config.NewComponentID(config.Type(name)),
 	}
 
-	scrp.EndMetricsOp(ctx, count, err)
-	return md, err
+	return ms, nil
 }
diff --git a/receiver/scraperhelper/scrapercontroller.go b/receiver/scraperhelper/scrapercontroller.go
@@ -186,14 +186,22 @@ func (sc *controller) scrapeMetricsAndReport(ctx context.Context) {
 	metrics := pdata.NewMetrics()
 
 	for _, scraper := range sc.scrapers {
-		md, err := scraper.Scrape(ctx, sc.id, sc.recvSettings)
+		scrp := obsreport.NewScraper(obsreport.ScraperSettings{
+			ReceiverID:             sc.id,
+			Scraper:                scraper.ID(),
+			ReceiverCreateSettings: sc.recvSettings,
+		})
+		ctx = scrp.StartMetricsOp(ctx)
+		md, err := scraper.Scrape(ctx)
+
 		if err != nil {
 			sc.logger.Error("Error scraping metrics", zap.Error(err), zap.Stringer("scraper", scraper.ID()))
-
 			if !scrapererror.IsPartialScrapeError(err) {
+				scrp.EndMetricsOp(ctx, 0, err)
 				continue
 			}
 		}
+		scrp.EndMetricsOp(ctx, md.MetricCount(), err)
 		md.ResourceMetrics().MoveAndAppendTo(metrics.ResourceMetrics())
 	}