prometheusreceiver: use gopsutil to gather collector start time on component initialization

Author: ridwanmsharif

receiver/prometheusreceiver/go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/prometheus/client_golang v1.20.5
 	github.com/prometheus/common v0.61.0
 	github.com/prometheus/prometheus v0.54.1
+	github.com/shirou/gopsutil/v4 v4.24.12
 	github.com/stretchr/testify v1.10.0
 	go.opentelemetry.io/collector/component v0.117.1-0.20250119231113-f07ebc3afb51
 	go.opentelemetry.io/collector/component/componentstatus v0.117.1-0.20250119231113-f07ebc3afb51
@@ -156,7 +157,6 @@ require (
 	github.com/prometheus/procfs v0.15.1 // indirect
 	github.com/rs/cors v1.11.1 // indirect
 	github.com/scaleway/scaleway-sdk-go v1.0.0-beta.29 // indirect
-	github.com/shirou/gopsutil/v4 v4.24.12 // indirect
 	github.com/spf13/cobra v1.8.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/tidwall/gjson v1.10.2 // indirect

receiver/prometheusreceiver/internal/starttimemetricadjuster.go

@@ -5,9 +5,11 @@ package internal // import "github.com/open-telemetry/opentelemetry-collector-co
 
 import (
 	"errors"
+	"os"
 	"regexp"
 	"time"
 
+	"github.com/shirou/gopsutil/v4/process"
 	"go.opentelemetry.io/collector/pdata/pmetric"
 	"go.uber.org/zap"
 )
@@ -17,15 +19,25 @@ var (
 	errNoDataPointsStartTimeMetric    = errors.New("start time metric with no data points")
 	errUnsupportedTypeStartTimeMetric = errors.New("unsupported data type for start time metric")
 
-	// approximateCollectorStartTime is the approximate start time of the collector. Used
+	// collectorStartTime is the approximate start time of the collector. Used
 	// as a fallback start time for metrics that don't have a start time set.
 	// Set when the component is initialized.
-	approximateCollectorStartTime *time.Time
+	collectorStartTime *time.Time
 )
 
 func init() {
-	now := time.Now()
-	approximateCollectorStartTime = &now
+	p, err := process.NewProcess(int32(os.Getpid()))
+	if err != nil {
+		panic("Unable to find current process" + err.Error())
+	}
+
+	ct, err := p.CreateTime()
+	if err != nil {
+		panic("Unable to find process start time" + err.Error())
+	}
+
+	startTime := time.Unix(ct/1000, 0) // Convert milliseconds to seconds
+	collectorStartTime = &startTime
 }
 
 type startTimeMetricAdjuster struct {
@@ -38,7 +50,7 @@ type startTimeMetricAdjuster struct {
 func NewStartTimeMetricAdjuster(logger *zap.Logger, startTimeMetricRegex *regexp.Regexp, useCollectorStartTimeFallback bool) MetricsAdjuster {
 	var fallbackStartTime *time.Time
 	if useCollectorStartTimeFallback {
-		fallbackStartTime = approximateCollectorStartTime
+		fallbackStartTime = collectorStartTime
 	}
 	return &startTimeMetricAdjuster{
 		startTimeMetricRegex: startTimeMetricRegex,