Add device name as a tag in disk stats (#1807)

* return partition stat alongside disk stat from disk usage method, and report device name (minus /dev/) as a tag in disk stats

* update system/disk tests to include new partition stat return value from disk usage method calls

* update changelog for #1807 (use device name instead of path to report disk stats)

CHANGELOG.md

@@ -9,6 +9,7 @@
 - [#1997](https://github.com/influxdata/telegraf/issues/1997): Non-default HTTP timeouts for RabbitMQ plugin.
 - [#2074](https://github.com/influxdata/telegraf/pull/2074): "discard" output plugin added, primarily for testing purposes.
 - [#1965](https://github.com/influxdata/telegraf/pull/1965): The JSON parser can now parse an array of objects using the same configuration.
+- [#1807](https://github.com/influxdata/telegraf/pull/1807): Option to use device name rather than path for reporting disk stats.
 
 ### Bugfixes
 

plugins/inputs/system/disk.go

@@ -2,6 +2,7 @@ package system
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
@@ -41,18 +42,19 @@ func (s *DiskStats) Gather(acc telegraf.Accumulator) error {
 		s.MountPoints = s.Mountpoints
 	}
 
-	disks, err := s.ps.DiskUsage(s.MountPoints, s.IgnoreFS)
+	disks, partitions, err := s.ps.DiskUsage(s.MountPoints, s.IgnoreFS)
 	if err != nil {
 		return fmt.Errorf("error getting disk usage info: %s", err)
 	}
 
-	for _, du := range disks {
+	for i, du := range disks {
 		if du.Total == 0 {
 			// Skip dummy filesystem (procfs, cgroupfs, ...)
 			continue
 		}
 		tags := map[string]string{
 			"path":   du.Path,
+			"device": strings.Replace(partitions[i].Device, "/dev/", "", -1),
 			"fstype": du.Fstype,
 		}
 		var used_percent float64

plugins/inputs/system/disk_test.go

@@ -50,9 +50,33 @@ func TestDiskStats(t *testing.T) {
 		},
 	}
 
-	mps.On("DiskUsage", []string(nil), []string(nil)).Return(duAll, nil)
+	psAll := []*disk.PartitionStat{
-	mps.On("DiskUsage", []string{"/", "/dev"}, []string(nil)).Return(duFiltered, nil)
+		{
-	mps.On("DiskUsage", []string{"/", "/home"}, []string(nil)).Return(duAll, nil)
+			Device:     "/dev/sda",
+			Mountpoint: "/",
+			Fstype:     "ext4",
+			Opts:       "",
+		},
+		{
+			Device:     "/dev/sdb",
+			Mountpoint: "/home",
+			Fstype:     "ext4",
+			Opts:       "",
+		},
+	}
+
+	psFiltered := []*disk.PartitionStat{
+		{
+			Device:     "/dev/sda",
+			Mountpoint: "/",
+			Fstype:     "ext4",
+			Opts:       "",
+		},
+	}
+
+	mps.On("DiskUsage", []string(nil), []string(nil)).Return(duAll, psAll, nil)
+	mps.On("DiskUsage", []string{"/", "/dev"}, []string(nil)).Return(duFiltered, psFiltered, nil)
+	mps.On("DiskUsage", []string{"/", "/home"}, []string(nil)).Return(duAll, psAll, nil)
 
 	err = (&DiskStats{ps: &mps}).Gather(&acc)
 	require.NoError(t, err)
@@ -64,10 +88,12 @@ func TestDiskStats(t *testing.T) {
 	tags1 := map[string]string{
 		"path":   "/",
 		"fstype": "ext4",
+		"device": "sda",
 	}
 	tags2 := map[string]string{
 		"path":   "/home",
 		"fstype": "ext4",
+		"device": "sdb",
 	}
 
 	fields1 := map[string]interface{}{

plugins/inputs/system/mock_PS.go

@@ -33,13 +33,14 @@ func (m *MockPS) CPUTimes(perCPU, totalCPU bool) ([]cpu.TimesStat, error) {
 	return r0, r1
 }
 
-func (m *MockPS) DiskUsage(mountPointFilter []string, fstypeExclude []string) ([]*disk.UsageStat, error) {
+func (m *MockPS) DiskUsage(mountPointFilter []string, fstypeExclude []string) ([]*disk.UsageStat, []*disk.PartitionStat, error) {
 	ret := m.Called(mountPointFilter, fstypeExclude)
 
 	r0 := ret.Get(0).([]*disk.UsageStat)
-	r1 := ret.Error(1)
+	r1 := ret.Get(1).([]*disk.PartitionStat)
+	r2 := ret.Error(2)
 
-	return r0, r1
+	return r0, r1, r2
 }
 
 func (m *MockPS) NetIO() ([]net.IOCountersStat, error) {

plugins/inputs/system/ps.go

@@ -14,7 +14,7 @@ import (
 
 type PS interface {
 	CPUTimes(perCPU, totalCPU bool) ([]cpu.TimesStat, error)
-	DiskUsage(mountPointFilter []string, fstypeExclude []string) ([]*disk.UsageStat, error)
+	DiskUsage(mountPointFilter []string, fstypeExclude []string) ([]*disk.UsageStat, []*disk.PartitionStat, error)
 	NetIO() ([]net.IOCountersStat, error)
 	NetProto() ([]net.ProtoCountersStat, error)
 	DiskIO() (map[string]disk.IOCountersStat, error)
@@ -54,10 +54,10 @@ func (s *systemPS) CPUTimes(perCPU, totalCPU bool) ([]cpu.TimesStat, error) {
 func (s *systemPS) DiskUsage(
 	mountPointFilter []string,
 	fstypeExclude []string,
-) ([]*disk.UsageStat, error) {
+) ([]*disk.UsageStat, []*disk.PartitionStat, error) {
 	parts, err := disk.Partitions(true)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// Make a "set" out of the filter slice
@@ -71,6 +71,7 @@ func (s *systemPS) DiskUsage(
 	}
 
 	var usage []*disk.UsageStat
+	var partitions []*disk.PartitionStat
 
 	for _, p := range parts {
 		if len(mountPointFilter) > 0 {
@@ -85,9 +86,10 @@ func (s *systemPS) DiskUsage(
 		if _, err := os.Stat(mountpoint); err == nil {
 			du, err := disk.Usage(mountpoint)
 			if err != nil {
-				return nil, err
+				return nil, nil, err
 			}
 			du.Path = p.Mountpoint
+
 			// If the mount point is a member of the exclude set,
 			// don't gather info on it.
 			_, ok := fstypeExcludeSet[p.Fstype]
@@ -96,10 +98,11 @@ func (s *systemPS) DiskUsage(
 			}
 			du.Fstype = p.Fstype
 			usage = append(usage, du)
+			partitions = append(partitions, &p)
 		}
 	}
 
-	return usage, nil
+	return usage, partitions, nil
 }
 
 func (s *systemPS) NetProto() ([]net.ProtoCountersStat, error) {