fix: Count the number of vCPUs instead of the number of CPU cores

Based on the available documents, the client should collect and export "a single
metric that counts the number of VCPUs on the system". Let's use a value that
can be calculated as: `cat /proc/cpuinfo | grep processor | wc -l`

There are several alternative options and methods to consider, but let's start
with the easist one that doesn't require any additional dependencies.

Use the metric name `system_cpu_logical_count` that follows semantic conventions
for OTEL: open-telemetry/semantic-conventions#99

hostinfo/cpu.go

@@ -19,11 +19,6 @@ func GetCPUCount() (uint, error) {
 		return 0, fmt.Errorf("GetCPUCount: failed to load CPUInfo: %w", err)
 	}
 
-	if len(info) == 0 {
-		return 0, fmt.Errorf("GetCPUCount: no value in CPUInfo")
-	}
-
-	cpuCores := info[0].CPUCores
-
-	return cpuCores, nil
+	cpuCount := uint(len(info))
+	return cpuCount, nil
 }

hostinfo/info.go

@@ -7,15 +7,15 @@ import (
 )
 
 type HostInfo struct {
-	CpuCoreCount uint
-	HostId       string
-	CertPath     string
-	CertKeyPath  string
+	CpuCount    uint
+	HostId      string
+	CertPath    string
+	CertKeyPath string
 }
 
 func LoadHostInfo(c *config.Config) (*HostInfo, error) {
 
-	cpuCoreCount, err := GetCPUCount()
+	cpuCount, err := GetCPUCount()
 	if err != nil {
 		return nil, err
 	}
@@ -26,16 +26,16 @@ func LoadHostInfo(c *config.Config) (*HostInfo, error) {
 	}
 
 	return &HostInfo{
-		CpuCoreCount: cpuCoreCount,
-		HostId:       hostId,
-		CertPath:     GetCertPath(c),
-		CertKeyPath:  GetCertKeyPath(c),
+		CpuCount:    cpuCount,
+		HostId:      hostId,
+		CertPath:    GetCertPath(c),
+		CertKeyPath: GetCertKeyPath(c),
 	}, nil
 }
 
 func (hi *HostInfo) Print() {
 	fmt.Println("HostInfo:")
-	fmt.Println("  CpuCoreCount: ", hi.CpuCoreCount)
+	fmt.Println("  CpuCount: ", hi.CpuCount)
 	fmt.Println("  HostId: ", hi.HostId)
 	fmt.Println("  CertPath: ", hi.CertPath)
 	fmt.Println("  CertKeyPath: ", hi.CertKeyPath)

notify/prometheus.go

@@ -91,7 +91,7 @@ func hostInfo2WriteRequest(hostinfo *hostinfo.HostInfo) *prompb.WriteRequest {
 	labels := []prompb.Label{
 		{
 			Name:  "__name__",
-			Value: "cpu_core_count",
+			Value: "system_cpu_logical_count",
 		},
 		{
 			Name:  "hostId",
@@ -101,7 +101,7 @@ func hostInfo2WriteRequest(hostinfo *hostinfo.HostInfo) *prompb.WriteRequest {
 
 	samples := []prompb.Sample{
 		{
-			Value:     float64(hostinfo.CpuCoreCount),
+			Value:     float64(hostinfo.CpuCount),
 			Timestamp: timestamp,
 		},
 	}