add disk usage

component/session/utils.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	C "github.com/shirou/gopsutil/cpu"
+	D "github.com/shirou/gopsutil/disk"
 	M "github.com/shirou/gopsutil/mem"
 )
 
@@ -23,6 +24,14 @@ func cpu() string {
 	return fmt.Sprintf("%.1f%%", c[0])
 }
 
+func disk() string {
+	d, err := D.Usage("/")
+	if err != nil {
+		return "N/A"
+	}
+	return fmt.Sprintf("%.1f%%", d.UsedPercent)
+}
+
 func mem() string {
 	m, err := M.VirtualMemory()
 	if err != nil {