From 9dbd4898b2ac91fa4a261cf75c9b55f2cf2f8e5d Mon Sep 17 00:00:00 2001
From: Shirou WAKAYAMA <shirou.faw@gmail.com>
Date: Mon, 22 Sep 2014 16:35:47 +0900
Subject: [PATCH] add SerialNumber to DiskIOCounterStat.

---
 disk.go       | 17 +++++++++--------
 disk_linux.go | 23 +++++++++++++++++++++++
 disk_test.go  | 13 +++++++------
 3 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/disk.go b/disk.go
index a76771e..d94caf7 100644
--- a/disk.go
+++ b/disk.go
@@ -24,14 +24,15 @@ type DiskPartitionStat struct {
 }
 
 type DiskIOCountersStat struct {
-	ReadCount  uint64 `json:"readCount"`
-	WriteCount uint64 `json:"writeCount"`
-	ReadBytes  uint64 `json:"readBytes"`
-	WriteBytes uint64 `json:"writeBytes"`
-	ReadTime   uint64 `json:"readTime"`
-	WriteTime  uint64 `json:"writeTime"`
-	Name       string `json:"name"`
-	IoTime     uint64 `json:"ioTime"`
+	ReadCount    uint64 `json:"readCount"`
+	WriteCount   uint64 `json:"writeCount"`
+	ReadBytes    uint64 `json:"readBytes"`
+	WriteBytes   uint64 `json:"writeBytes"`
+	ReadTime     uint64 `json:"readTime"`
+	WriteTime    uint64 `json:"writeTime"`
+	Name         string `json:"name"`
+	IoTime       uint64 `json:"ioTime"`
+	SerialNumber string `json:"serialNumber"`
 }
 
 func (d DiskUsageStat) String() string {
diff --git a/disk_linux.go b/disk_linux.go
index bfcc9f1..25a5ad1 100644
--- a/disk_linux.go
+++ b/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
+}
diff --git a/disk_test.go b/disk_test.go
index 2ced8b7..0f20030 100644
--- a/disk_test.go
+++ b/disk_test.go
@@ -79,13 +79,14 @@ func TestDiskPartitionStat_String(t *testing.T) {
 
 func TestDiskIOCountersStat_String(t *testing.T) {
 	v := DiskIOCountersStat{
-		Name:       "sd01",
-		ReadCount:  100,
-		WriteCount: 200,
-		ReadBytes:  300,
-		WriteBytes: 400,
+		Name:         "sd01",
+		ReadCount:    100,
+		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)
 	}