agent: add system-info endpoint

internal/metrics/system_info.go

@@ -0,0 +1,62 @@
+package metrics
+
+import (
+	"context"
+	"encoding/json"
+	"time"
+
+	"github.com/shirou/gopsutil/v4/cpu"
+	"github.com/shirou/gopsutil/v4/disk"
+	"github.com/shirou/gopsutil/v4/mem"
+	"github.com/yusing/go-proxy/internal/utils/strutils"
+)
+
+type (
+	SystemInfo struct {
+		CPUAverage float64
+		Memory     *mem.VirtualMemoryStat
+		Disk       *disk.UsageStat
+	}
+)
+
+func GetSystemInfo(ctx context.Context) (*SystemInfo, error) {
+	memoryInfo, err := mem.VirtualMemory()
+	if err != nil {
+		return nil, err
+	}
+	cpuAverage, err := cpu.PercentWithContext(ctx, time.Second, false)
+	if err != nil {
+		return nil, err
+	}
+
+	diskInfo, err := disk.Usage("/")
+	if err != nil {
+		return nil, err
+	}
+
+	return &SystemInfo{
+		CPUAverage: cpuAverage[0],
+		Memory:     memoryInfo,
+		Disk:       diskInfo,
+	}, nil
+}
+
+func (info *SystemInfo) MarshalJSON() ([]byte, error) {
+	return json.Marshal(map[string]interface{}{
+		"cpu_average": info.CPUAverage,
+		"memory": map[string]interface{}{
+			"total":        strutils.FormatByteSize(info.Memory.Total),
+			"available":    strutils.FormatByteSize(info.Memory.Available),
+			"used":         strutils.FormatByteSize(info.Memory.Used),
+			"used_percent": info.Memory.UsedPercent,
+			"free":         strutils.FormatByteSize(info.Memory.Free),
+		},
+		"disk": map[string]interface{}{
+			"total":        strutils.FormatByteSize(info.Disk.Total),
+			"used":         strutils.FormatByteSize(info.Disk.Used),
+			"used_percent": info.Disk.UsedPercent,
+			"free":         strutils.FormatByteSize(info.Disk.Free),
+			"fs_type":      info.Disk.Fstype,
+		},
+	})
+}