add SerialNumber to DiskIOCounterStat.

disk.go

@@ -32,6 +32,7 @@ type DiskIOCountersStat struct {
 	WriteTime    uint64 `json:"writeTime"`
 	Name         string `json:"name"`
 	IoTime       uint64 `json:"ioTime"`
+	SerialNumber string `json:"serialNumber"`
 }
 
 func (d DiskUsageStat) String() string {

disk_linux.go

@@ -3,6 +3,8 @@
 package gopsutil
 
 import (
+	"fmt"
+	"os/exec"
 	"strconv"
 	"strings"
 )
@@ -91,7 +93,28 @@ func DiskIOCounters() (map[string]DiskIOCountersStat, error) {
 		}
 		d.Name = name
 
+		d.SerialNumber = GetDiskSerialNumber(name)
 		ret[name] = d
 	}
 	return ret, nil
 }
+
+func GetDiskSerialNumber(name string) (string, error) {
+	n := fmt.Sprintf("--name=%s", name)
+	out, err := exec.Command("/sbin/udevadm", "info", "--query=property", n).Output()
+
+	// does not return error, just an empty string
+	if err != nil {
+		return "", nil
+	}
+	lines := strings.Split(string(out), "\n")
+	for _, line := range lines {
+		values := strings.Split(line, "=")
+		if len(values) < 2 || values[0] != "ID_SERIAL" {
+			// only get ID_SERIAL, not ID_SERIAL_SHORT
+			continue
+		}
+		return values[1], nil
+	}
+	return "", nil
+}

disk_test.go

@@ -84,8 +84,9 @@ func TestDiskIOCountersStat_String(t *testing.T) {
 		WriteCount:   200,
 		ReadBytes:    300,
 		WriteBytes:   400,
+		SerialNumber: "SERIAL",
 	}
-	e := `{"readCount":100,"writeCount":200,"readBytes":300,"writeBytes":400,"readTime":0,"writeTime":0,"name":"sd01","ioTime":0}`
+	e := `{"readCount":100,"writeCount":200,"readBytes":300,"writeBytes":400,"readTime":0,"writeTime":0,"name":"sd01","ioTime":0,"serialNumber":"SERIAL"}`
 	if e != fmt.Sprintf("%v", v) {
 		t.Errorf("DiskUsageStat string is invalid: %v", v)
 	}