agent: add system-info endpoint

internal/utils/strutils/format.go

@@ -2,6 +2,7 @@ package strutils
 
 import (
 	"fmt"
+	"math"
 	"strconv"
 	"strings"
 	"time"
@@ -65,6 +66,39 @@ func ParseBool(s string) bool {
 	}
 }
 
+func formatFloat(f float64) string {
+	f = math.Round(f*100) / 100
+	if f == 0 {
+		return "0"
+	}
+	return strconv.FormatFloat(f, 'f', -1, 64)
+}
+
+func FormatByteSize[T ~uint64](size T) string {
+	const (
+		_ = (1 << (10 * iota))
+		kb
+		mb
+		gb
+		tb
+		pb
+	)
+	switch {
+	case size < kb:
+		return fmt.Sprintf("%d B", size)
+	case size < mb:
+		return formatFloat(float64(size)/kb) + "KiB"
+	case size < gb:
+		return formatFloat(float64(size)/mb) + "MiB"
+	case size < tb:
+		return formatFloat(float64(size)/gb) + "GiB"
+	case size < pb:
+		return formatFloat(float64(size/gb)/kb) + "TiB" // prevent overflow
+	default:
+		return formatFloat(float64(size/tb)/kb) + "PiB" // prevent overflow
+	}
+}
+
 func PortString(port uint16) string {
 	return strconv.FormatUint(uint64(port), 10)
 }