add resource to vmreceiver. (#31)

* add resource to vmreceiver.

* add panic if resource detection fails.

* add sync.Once around resource detection.

go.mod

@@ -6,6 +6,7 @@ require (
 	contrib.go.opencensus.io/exporter/ocagent v0.5.0
 	contrib.go.opencensus.io/exporter/prometheus v0.1.0
 	contrib.go.opencensus.io/exporter/zipkin v0.1.1
+	contrib.go.opencensus.io/resource v0.1.1
 	github.com/VividCortex/gohistogram v1.0.0 // indirect
 	github.com/apache/thrift v0.0.0-20161221203622-b2a4d4ae21c7
 	github.com/aws/aws-sdk-go v1.19.18 // indirect

go.sum

@@ -11,6 +11,8 @@ contrib.go.opencensus.io/exporter/prometheus v0.1.0 h1:SByaIoWwNgMdPSgl5sMqM2KDE
 contrib.go.opencensus.io/exporter/prometheus v0.1.0/go.mod h1:cGFniUXGZlKRjzOyuZJ6mgB+PgBcCIa79kEKR8YCW+A=
 contrib.go.opencensus.io/exporter/zipkin v0.1.1 h1:PR+1zWqY8ceXs1qDQQIlgXe+sdiwCf0n32bH4+Epk8g=
 contrib.go.opencensus.io/exporter/zipkin v0.1.1/go.mod h1:GMvdSl3eJ2gapOaLKzTKE3qDgUkJ86k9k3yY2eqwkzc=
+contrib.go.opencensus.io/resource v0.1.1 h1:4r2CANuYhKGmYWP02+5E94rLRcS/YeD+KlxSrOsMxk0=
+contrib.go.opencensus.io/resource v0.1.1/go.mod h1:F361eGI91LCmW1I/Saf+rX0+OFcigGlFvXwEGEnkRLA=
 github.com/Azure/azure-sdk-for-go v0.0.0-20161028183111-bd73d950fa44 h1:L4fLiifszjLnCRGi6Xhp0MgUwjIMbVXKbayoRiVxkU8=
 github.com/Azure/azure-sdk-for-go v0.0.0-20161028183111-bd73d950fa44/go.mod h1:9XXNKU+eRnpl9moKnB4QOLf1HestfXbmab5FXxiDBjc=
 github.com/Azure/go-autorest v10.8.1+incompatible h1:u0jVQf+a6k6x8A+sT60l6EY9XZu+kHdnZVPAYqpVRo0=

receiver/vmmetricsreceiver/vm_metrics_collector.go

@@ -19,6 +19,7 @@ import (
 	"fmt"
 	"os"
 	"runtime"
+	"sync"
 	"time"
 
 	"github.com/prometheus/procfs"
@@ -28,7 +29,9 @@ import (
 	"github.com/open-telemetry/opentelemetry-service/data"
 	"github.com/open-telemetry/opentelemetry-service/internal"
 
+	"contrib.go.opencensus.io/resource/auto"
 	metricspb "github.com/census-instrumentation/opencensus-proto/gen-go/metrics/v1"
+	resourcepb "github.com/census-instrumentation/opencensus-proto/gen-go/resource/v1"
 )
 
 // VMMetricsCollector is a struct that collects and reports VM and process metrics (cpu, mem, etc).
@@ -51,6 +54,9 @@ const (
 	defaultScrapeInterval = 10 * time.Second
 )
 
+var rsc *resourcepb.Resource
+var resourceDetectionSync sync.Once
+
 // NewVMMetricsCollector creates a new set of VM and Process Metrics (mem, cpu).
 func NewVMMetricsCollector(si time.Duration, mountPoint, processMountPoint, prefix string, consumer consumer.MetricsConsumer) (*VMMetricsCollector, error) {
 	if mountPoint == "" {
@@ -84,8 +90,28 @@ func NewVMMetricsCollector(si time.Duration, mountPoint, processMountPoint, pref
 	return vmc, nil
 }
 
+func detectResource() {
+	resourceDetectionSync.Do(func() {
+		res, err := auto.Detect(context.Background())
+		if err != nil {
+			panic(fmt.Sprintf("Resource detection failed, err:%v", err))
+		}
+		if res != nil {
+			rsc = &resourcepb.Resource{
+				Type:   res.Type,
+				Labels: make(map[string]string, len(res.Labels)),
+			}
+			for k, v := range res.Labels {
+				rsc.Labels[k] = v
+			}
+		}
+	})
+}
+
 // StartCollection starts a ticker'd goroutine that will scrape and export vm metrics periodically.
 func (vmc *VMMetricsCollector) StartCollection() {
+	detectResource()
+
 	go func() {
 		ticker := time.NewTicker(vmc.scrapeInterval)
 		for {
@@ -118,14 +144,17 @@ func (vmc *VMMetricsCollector) scrapeAndExport() {
 		metrics,
 		&metricspb.Metric{
 			MetricDescriptor: metricAllocMem,
+			Resource:         rsc,
 			Timeseries:       []*metricspb.TimeSeries{vmc.getInt64TimeSeries(ms.Alloc)},
 		},
 		&metricspb.Metric{
 			MetricDescriptor: metricTotalAllocMem,
+			Resource:         rsc,
 			Timeseries:       []*metricspb.TimeSeries{vmc.getInt64TimeSeries(ms.TotalAlloc)},
 		},
 		&metricspb.Metric{
 			MetricDescriptor: metricSysMem,
+			Resource:         rsc,
 			Timeseries:       []*metricspb.TimeSeries{vmc.getInt64TimeSeries(ms.Sys)},
 		},
 	)
@@ -140,6 +169,7 @@ func (vmc *VMMetricsCollector) scrapeAndExport() {
 				metrics,
 				&metricspb.Metric{
 					MetricDescriptor: metricProcessCPUSeconds,
+					Resource:         rsc,
 					Timeseries:       []*metricspb.TimeSeries{vmc.getDoubleTimeSeries(procStat.CPUTime(), nil)},
 				},
 			)
@@ -156,18 +186,22 @@ func (vmc *VMMetricsCollector) scrapeAndExport() {
 			metrics,
 			&metricspb.Metric{
 				MetricDescriptor: metricProcessesRunning,
+				Resource:         rsc,
 				Timeseries:       []*metricspb.TimeSeries{vmc.getInt64TimeSeries(stat.ProcessesRunning)},
 			},
 			&metricspb.Metric{
 				MetricDescriptor: metricProcessesBlocked,
+				Resource:         rsc,
 				Timeseries:       []*metricspb.TimeSeries{vmc.getInt64TimeSeries(stat.ProcessesBlocked)},
 			},
 			&metricspb.Metric{
 				MetricDescriptor: metricProcessesCreated,
+				Resource:         rsc,
 				Timeseries:       []*metricspb.TimeSeries{vmc.getInt64TimeSeries(stat.ProcessCreated)},
 			},
 			&metricspb.Metric{
 				MetricDescriptor: metricCPUSeconds,
+				Resource:         rsc,
 				Timeseries: []*metricspb.TimeSeries{
 					vmc.getDoubleTimeSeries(cpuStat.User, labelValueCPUUser),
 					vmc.getDoubleTimeSeries(cpuStat.System, labelValueCPUSystem),