[receiver/hostmetrics] Migrate memory scraper to the new metrics builder

CHANGELOG.md

@@ -25,6 +25,7 @@
 - `postgresreceiver`: Update to mdatagen v2 (#7503)
 - `nginxreceiver`: Update to mdatagen v2 (#7549)
 - `datadogexporter`: Fix traces exporter's initialization log (#7564)
+- `hostreceiver/memoryscraper`: Migrate the scraper to the mdatagen metrics builder (#7421)
 - `tailsamplingprocessor`: Add And sampling policy (#6910)
 
 ## 🛑 Breaking changes 🛑

receiver/hostmetricsreceiver/config_test.go

@@ -75,7 +75,7 @@ func TestLoadConfig(t *testing.T) {
 				return cfg
 			})(),
 			filesystemscraper.TypeStr: &filesystemscraper.Config{},
-			memoryscraper.TypeStr:     &memoryscraper.Config{},
+			memoryscraper.TypeStr:     (&memoryscraper.Factory{}).CreateDefaultConfig(),
 			networkscraper.TypeStr: (func() internal.Config {
 				cfg := (&networkscraper.Factory{}).CreateDefaultConfig()
 				cfg.(*networkscraper.Config).Include = networkscraper.MatchConfig{

receiver/hostmetricsreceiver/hostmetrics_receiver_test.go

@@ -109,7 +109,7 @@ func TestGatherMetrics_EndToEnd(t *testing.T) {
 			diskscraper.TypeStr:       scraperFactories[diskscraper.TypeStr].CreateDefaultConfig(),
 			filesystemscraper.TypeStr: &filesystemscraper.Config{},
 			loadscraper.TypeStr:       scraperFactories[loadscraper.TypeStr].CreateDefaultConfig(),
-			memoryscraper.TypeStr:     &memoryscraper.Config{},
+			memoryscraper.TypeStr:     scraperFactories[memoryscraper.TypeStr].CreateDefaultConfig(),
 			networkscraper.TypeStr:    scraperFactories[networkscraper.TypeStr].CreateDefaultConfig(),
 			pagingscraper.TypeStr:     &pagingscraper.Config{},
 			processesscraper.TypeStr:  &processesscraper.Config{},

receiver/hostmetricsreceiver/internal/scraper/memoryscraper/config.go

@@ -14,9 +14,15 @@
 
 package memoryscraper // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/hostmetricsreceiver/internal/scraper/memoryscraper"
 
-import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/hostmetricsreceiver/internal"
+import (
+	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/hostmetricsreceiver/internal"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/hostmetricsreceiver/internal/scraper/memoryscraper/internal/metadata"
+)
 
 // Config relating to Memory Metric Scraper.
 type Config struct {
 	internal.ConfigSettings `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct
+
+	// Metrics allows to customize scraped metrics representation.
+	Metrics metadata.MetricsSettings `mapstructure:"metrics"`
 }

receiver/hostmetricsreceiver/internal/scraper/memoryscraper/doc.go

@@ -15,6 +15,6 @@
 //go:build !windows
 // +build !windows
 
-//go:generate mdatagen metadata.yaml
+//go:generate mdatagen --experimental-gen metadata.yaml
 
 package memoryscraper // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/hostmetricsreceiver/internal/scraper/memoryscraper"

receiver/hostmetricsreceiver/internal/scraper/memoryscraper/factory.go

@@ -21,6 +21,7 @@ import (
 	"go.uber.org/zap"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/hostmetricsreceiver/internal"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/hostmetricsreceiver/internal/scraper/memoryscraper/internal/metadata"
 )
 
 // This file implements Factory for Memory scraper.
@@ -36,7 +37,9 @@ type Factory struct {
 
 // CreateDefaultConfig creates the default configuration for the Scraper.
 func (f *Factory) CreateDefaultConfig() internal.Config {
-	return &Config{}
+	return &Config{
+		Metrics: metadata.DefaultMetricsSettings(),
+	}
 }
 
 // CreateMetricsScraper creates a scraper based on provided config.
@@ -48,5 +51,8 @@ func (f *Factory) CreateMetricsScraper(
 	cfg := config.(*Config)
 	s := newMemoryScraper(ctx, cfg)
 
-	return scraperhelper.NewScraper(TypeStr, s.Scrape)
+	return scraperhelper.NewScraper(TypeStr,
+		s.scrape,
+		scraperhelper.WithStart(s.start),
+	)
 }