hostmetricsreceiver: refactor load metrics to use metadata generated …

…metrics

cmd/mdatagen/metrics.tmpl

@@ -24,7 +24,7 @@ import (
 // Type is the component type name.
 const Type configmodels.Type = "{{ .Name }}"
 
-type metricIntf interface {
+type Metric interface {
 	Name() string
 	New() pdata.Metric
 	Init(metric pdata.Metric)
@@ -55,7 +55,7 @@ func (m *metricImpl) Init(metric pdata.Metric) {
 
 type metricStruct struct {
 	{{- range $name, $metric := .Metrics }}
-	{{ $name.Render }} metricIntf
+	{{ $name.Render }} Metric
 	{{- end }}
 }
 
@@ -68,13 +68,13 @@ func (m *metricStruct) Names() []string {
     }
 }
 
-var metricsByName = map[string]metricIntf {
+var metricsByName = map[string]Metric {
 {{- range $name, $metric := .Metrics }}
   "{{ $name }}": Metrics.{{ $name.Render }},
 {{- end }}
 }
 
-func (m *metricStruct) ByName(n string) metricIntf {
+func (m *metricStruct) ByName(n string) Metric {
     return metricsByName[n]
 }
 

receiver/hostmetricsreceiver/internal/metadata/.nocover

@@ -0,0 +1 @@
+We test the generated code in the package it is used.

receiver/hostmetricsreceiver/internal/scraper/loadscraper/load_scraper.go

@@ -25,6 +25,7 @@ import (
 	"go.opentelemetry.io/collector/consumer/consumererror"
 	"go.opentelemetry.io/collector/consumer/pdata"
 	"go.opentelemetry.io/collector/receiver/hostmetricsreceiver/internal"
+	"go.opentelemetry.io/collector/receiver/hostmetricsreceiver/internal/metadata"
 )
 
 const metricsLen = 3
@@ -64,15 +65,15 @@ func (s *scraper) scrape(_ context.Context) (pdata.MetricSlice, error) {
 	}
 
 	metrics.Resize(metricsLen)
-	initializeLoadMetric(metrics.At(0), loadAvg1MDescriptor, now, avgLoadValues.Load1)
-	initializeLoadMetric(metrics.At(1), loadAvg5mDescriptor, now, avgLoadValues.Load5)
-	initializeLoadMetric(metrics.At(2), loadAvg15mDescriptor, now, avgLoadValues.Load15)
+
+	initializeLoadMetric(metrics.At(0), metadata.Metrics.SystemCPULoadAverage1m, now, avgLoadValues.Load1)
+	initializeLoadMetric(metrics.At(1), metadata.Metrics.SystemCPULoadAverage5m, now, avgLoadValues.Load5)
+	initializeLoadMetric(metrics.At(2), metadata.Metrics.SystemCPULoadAverage15m, now, avgLoadValues.Load15)
 	return metrics, nil
 }
 
-func initializeLoadMetric(metric pdata.Metric, metricDescriptor pdata.Metric, now pdata.TimestampUnixNano, value float64) {
-	metricDescriptor.CopyTo(metric)
-
+func initializeLoadMetric(metric pdata.Metric, metricDescriptor metadata.Metric, now pdata.TimestampUnixNano, value float64) {
+	metricDescriptor.Init(metric)
 	idps := metric.DoubleGauge().DataPoints()
 	idps.Resize(1)
 	dp := idps.At(0)

receiver/hostmetricsreceiver/internal/scraper/loadscraper/load_scraper_test.go

@@ -28,6 +28,7 @@ import (
 	"go.opentelemetry.io/collector/consumer/consumererror"
 	"go.opentelemetry.io/collector/consumer/pdata"
 	"go.opentelemetry.io/collector/receiver/hostmetricsreceiver/internal"
+	"go.opentelemetry.io/collector/receiver/hostmetricsreceiver/internal/metadata"
 )
 
 func TestScrape(t *testing.T) {
@@ -77,9 +78,9 @@ func TestScrape(t *testing.T) {
 			assert.Equal(t, 3, metrics.Len())
 
 			// expect a single datapoint for 1m, 5m & 15m load metrics
-			assertMetricHasSingleDatapoint(t, metrics.At(0), loadAvg1MDescriptor)
-			assertMetricHasSingleDatapoint(t, metrics.At(1), loadAvg5mDescriptor)
-			assertMetricHasSingleDatapoint(t, metrics.At(2), loadAvg15mDescriptor)
+			assertMetricHasSingleDatapoint(t, metrics.At(0), metadata.Metrics.SystemCPULoadAverage1m.New())
+			assertMetricHasSingleDatapoint(t, metrics.At(1), metadata.Metrics.SystemCPULoadAverage5m.New())
+			assertMetricHasSingleDatapoint(t, metrics.At(2), metadata.Metrics.SystemCPULoadAverage15m.New())
 
 			internal.AssertSameTimeStampForAllMetrics(t, metrics)
 		})

receiver/hostmetricsreceiver/metadata.yaml

@@ -32,3 +32,21 @@ metrics:
       type: int sum
       aggregation: cumulative
       monotonic: false
+
+  system.cpu.load_average.1m:
+    description: Average CPU Load over 1 minute.
+    unit: 1
+    data:
+      type: double gauge
+
+  system.cpu.load_average.5m:
+    description: Average CPU Load over 5 minutes.
+    unit: 1
+    data:
+      type: double gauge
+
+  system.cpu.load_average.15m:
+    description: Average CPU Load over 15 minutes.
+    unit: 1
+    data:
+      type: double gauge