From 67952f17f51b166b420b078fc9384e45b39f5c67 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Wed, 24 Aug 2016 22:41:53 +0300
Subject: [PATCH 01/18] Add dmcache input plugin

---
 plugins/inputs/all/all.go                  |   1 +
 plugins/inputs/dmcache/README.md           |  11 ++
 plugins/inputs/dmcache/dmcache.go          |  49 ++++++++
 plugins/inputs/dmcache/dmcache_linux.go    | 131 +++++++++++++++++++++
 plugins/inputs/dmcache/dmcache_notlinux.go |  11 ++
 plugins/inputs/dmcache/dmcache_test.go     |  94 +++++++++++++++
 6 files changed, 297 insertions(+)
 create mode 100644 plugins/inputs/dmcache/README.md
 create mode 100644 plugins/inputs/dmcache/dmcache.go
 create mode 100644 plugins/inputs/dmcache/dmcache_linux.go
 create mode 100644 plugins/inputs/dmcache/dmcache_notlinux.go
 create mode 100644 plugins/inputs/dmcache/dmcache_test.go

diff --git a/plugins/inputs/all/all.go b/plugins/inputs/all/all.go
index af759aac8ba4e..c7ac4762b476d 100644
--- a/plugins/inputs/all/all.go
+++ b/plugins/inputs/all/all.go
@@ -14,6 +14,7 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/inputs/couchbase"
 	_ "github.com/influxdata/telegraf/plugins/inputs/couchdb"
 	_ "github.com/influxdata/telegraf/plugins/inputs/disque"
+	_ "github.com/influxdata/telegraf/plugins/inputs/dmcache"
 	_ "github.com/influxdata/telegraf/plugins/inputs/dns_query"
 	_ "github.com/influxdata/telegraf/plugins/inputs/docker"
 	_ "github.com/influxdata/telegraf/plugins/inputs/dovecot"
diff --git a/plugins/inputs/dmcache/README.md b/plugins/inputs/dmcache/README.md
new file mode 100644
index 0000000000000..87931376e0e18
--- /dev/null
+++ b/plugins/inputs/dmcache/README.md
@@ -0,0 +1,11 @@
+# DMCache Input Plugin
+
+This plugin provide a native collection for dmsetup based statistics for dm-cache
+
+## Configuration
+
+```
+[[inputs.dmcache]]
+## Whether to report per-device stats or not
+	per_device = true
+```
diff --git a/plugins/inputs/dmcache/dmcache.go b/plugins/inputs/dmcache/dmcache.go
new file mode 100644
index 0000000000000..bfcb6dadcb751
--- /dev/null
+++ b/plugins/inputs/dmcache/dmcache.go
@@ -0,0 +1,49 @@
+package dmcache
+
+import (
+	"os/exec"
+	"strings"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+type DMCache struct {
+	PerDevice bool `toml:"per_device"`
+	rawStatus func() ([]string, error)
+}
+
+var sampleConfig = `
+	## Whether to report per-device stats or not
+	per_device = true
+`
+
+func (c *DMCache) SampleConfig() string {
+	return sampleConfig
+}
+
+func (c *DMCache) Description() string {
+	return "Provide a native collection for dmsetup based statistics for dm-cache"
+}
+
+func init() {
+	inputs.Add("dmcache", func() telegraf.Input {
+		return &DMCache{
+			PerDevice: true,
+			rawStatus: func() ([]string, error) {
+				out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
+				if err != nil {
+					return nil, err
+				}
+				if string(out) == "No devices found\n" {
+					return nil, nil
+				}
+
+				status := strings.Split(string(out), "\n")
+				status = status[:len(status)-1] // removing last empty line
+
+				return status, nil
+			},
+		}
+	})
+}
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
new file mode 100644
index 0000000000000..ed8b88c6809d3
--- /dev/null
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -0,0 +1,131 @@
+// +build linux
+
+package dmcache
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/influxdata/telegraf"
+)
+
+const metricName = "dmcache"
+
+var fieldNames = [...]string{
+	"metadata_used",
+	"metadata_free",
+	"cache_used",
+	"cache_free",
+	"read_hits",
+	"read_misses",
+	"write_hits",
+	"write_misses",
+	"demotions",
+	"promotions",
+	"dirty",
+}
+
+func (c *DMCache) Gather(acc telegraf.Accumulator) error {
+	outputLines, err := c.rawStatus()
+	if err != nil {
+		return err
+	}
+
+	var total map[string]interface{}
+	if !c.PerDevice {
+		total = make(map[string]interface{})
+	}
+
+	for _, s := range outputLines {
+		fields := make(map[string]interface{})
+		data, err := parseDMSetupStatus(s)
+		if err != nil {
+			return err
+		}
+
+		for _, f := range fieldNames {
+			fields[f] = calculateSize(data, f)
+		}
+
+		if c.PerDevice {
+			tags := map[string]string{"device": data["device"].(string)}
+			acc.AddFields(metricName, fields, tags)
+		} else {
+			aggregateStats(total, fields)
+		}
+	}
+
+	if !c.PerDevice {
+		acc.AddFields(metricName, total, nil)
+	}
+
+	return nil
+}
+
+func parseDMSetupStatus(line string) (status map[string]interface{}, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			status = nil
+			err = r.(error)
+		}
+	}()
+
+	values := strings.Split(line, " ")
+	status = make(map[string]interface{})
+
+	status["device"] = values[0][:len(values[0])-1]
+	status["length"] = toInt(values[2])
+	status["target"] = values[3]
+	status["metadata_blocksize"] = toInt(values[4])
+	status["metadata_used"] = toInt(strings.Split(values[5], "/")[0])
+	status["metadata_total"] = toInt(strings.Split(values[5], "/")[1])
+	status["cache_blocksize"] = toInt(values[6])
+	status["cache_used"] = toInt(strings.Split(values[7], "/")[0])
+	status["cache_total"] = toInt(strings.Split(values[7], "/")[1])
+	status["read_hits"] = toInt(values[8])
+	status["read_misses"] = toInt(values[9])
+	status["write_hits"] = toInt(values[10])
+	status["write_misses"] = toInt(values[11])
+	status["demotions"] = toInt(values[12])
+	status["promotions"] = toInt(values[13])
+	status["dirty"] = toInt(values[14])
+	status["blocksize"] = 512
+
+	return status, nil
+}
+
+func toInt(s string) int {
+	i, err := strconv.Atoi(s)
+	if err != nil {
+		panic(err)
+	}
+	return i
+}
+
+func calculateSize(data map[string]interface{}, key string) (value int) {
+	if key == "metadata_free" {
+		value = data["metadata_total"].(int) - data["metadata_used"].(int)
+	} else if key == "cache_free" {
+		value = data["cache_total"].(int) - data["cache_used"].(int) - data["dirty"].(int)
+	} else {
+		value = data[key].(int)
+	}
+
+	if key == "metadata_free" || key == "metadata_used" {
+		value = value * data["blocksize"].(int) * data["metadata_blocksize"].(int)
+	} else {
+		value = value * data["blocksize"].(int) * data["cache_blocksize"].(int)
+	}
+
+	return
+}
+
+func aggregateStats(total, fields map[string]interface{}) {
+	for key, value := range fields {
+		if _, ok := total[key]; ok {
+			total[key] = total[key].(int) + value.(int)
+		} else {
+			total[key] = value.(int)
+		}
+	}
+}
diff --git a/plugins/inputs/dmcache/dmcache_notlinux.go b/plugins/inputs/dmcache/dmcache_notlinux.go
new file mode 100644
index 0000000000000..478c2f163e4dc
--- /dev/null
+++ b/plugins/inputs/dmcache/dmcache_notlinux.go
@@ -0,0 +1,11 @@
+// +build !linux
+
+package dmcache
+
+import (
+	"github.com/influxdata/telegraf"
+)
+
+func (c *DMCache) Gather(acc telegraf.Accumulator) error {
+	return nil
+}
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
new file mode 100644
index 0000000000000..42d5072990802
--- /dev/null
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -0,0 +1,94 @@
+// +build linux
+
+package dmcache
+
+import (
+	"testing"
+
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/require"
+)
+
+func output2Devices() ([]string, error) {
+	return []string{
+		"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 15 46 0 7 0 1 writeback 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
+		"cs-2: 0 4294967296 cache 8 72352/1310720 128 26/24327168 2409 286 265 524682 0 0 0 1 writethrough 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
+	}, nil
+}
+
+var dmc1 = &DMCache{
+	PerDevice: true,
+	rawStatus: output2Devices,
+}
+
+func TestDMCacheStats_1(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc1.Gather(&acc)
+	require.NoError(t, err)
+
+	tags1 := map[string]string{
+		"device": "cs-1",
+	}
+	fields1 := map[string]interface{}{
+		"metadata_used": 4169728,
+		"metadata_free": 6144425984,
+		"cache_used":    1835008,
+		"cache_free":    121885163520,
+		"read_hits":     36438016,
+		"read_misses":   92443246592,
+		"write_hits":    3932160,
+		"write_misses":  12058624,
+		"demotions":     0,
+		"promotions":    1835008,
+		"dirty":         0,
+	}
+	acc.AssertContainsTaggedFields(t, "dmcache", fields1, tags1)
+
+	tags2 := map[string]string{
+		"device": "cs-2",
+	}
+	fields2 := map[string]interface{}{
+		"metadata_used": 296353792,
+		"metadata_free": 5072355328,
+		"cache_used":    1703936,
+		"cache_free":    1594303578112,
+		"read_hits":     157876224,
+		"read_misses":   18743296,
+		"write_hits":    17367040,
+		"write_misses":  34385559552,
+		"demotions":     0,
+		"promotions":    0,
+		"dirty":         0,
+	}
+	acc.AssertContainsTaggedFields(t, "dmcache", fields2, tags2)
+}
+
+var dmc2 = &DMCache{
+	PerDevice: false,
+	rawStatus: output2Devices,
+}
+
+func TestDMCacheStats_2(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc2.Gather(&acc)
+	require.NoError(t, err)
+
+	tags := map[string]string{}
+
+	fields := map[string]interface{}{
+		"metadata_used": 300523520,
+		"metadata_free": 11216781312,
+		"cache_used":    3538944,
+		"cache_free":    1716188741632,
+		"read_hits":     194314240,
+		"read_misses":   92461989888,
+		"write_hits":    21299200,
+		"write_misses":  34397618176,
+		"demotions":     0,
+		"promotions":    1835008,
+		"dirty":         0,
+	}
+	acc.AssertContainsTaggedFields(t, "dmcache", fields, tags)
+}

From 7143b600c8f70c729007659fe01381075783126e Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Wed, 29 Mar 2017 12:19:25 +0300
Subject: [PATCH 02/18] dmcache refactoring

---
 plugins/inputs/dmcache/README.md        |  10 ++-
 plugins/inputs/dmcache/dmcache.go       |   4 +-
 plugins/inputs/dmcache/dmcache_linux.go | 109 +++++++++++++++---------
 plugins/inputs/dmcache/dmcache_test.go  |  25 +++++-
 4 files changed, 99 insertions(+), 49 deletions(-)

diff --git a/plugins/inputs/dmcache/README.md b/plugins/inputs/dmcache/README.md
index 87931376e0e18..ae4142e9aa2fa 100644
--- a/plugins/inputs/dmcache/README.md
+++ b/plugins/inputs/dmcache/README.md
@@ -1,11 +1,15 @@
 # DMCache Input Plugin
 
-This plugin provide a native collection for dmsetup based statistics for dm-cache
+This plugin provide a native collection for dmsetup based statistics for dm-cache.
+
+This plugin requires sudo, that is why you should setup and be sure that the telegraf is able to execute sudo without a password.
+
+`sudo /sbin/dmsetup status --target cache` is the full command that telegraf will run for debugging purposes.
 
 ## Configuration
 
 ```
 [[inputs.dmcache]]
-## Whether to report per-device stats or not
-	per_device = true
+  ## Whether to report per-device stats or not
+  per_device = true
 ```
diff --git a/plugins/inputs/dmcache/dmcache.go b/plugins/inputs/dmcache/dmcache.go
index bfcb6dadcb751..c36eed636af77 100644
--- a/plugins/inputs/dmcache/dmcache.go
+++ b/plugins/inputs/dmcache/dmcache.go
@@ -14,8 +14,8 @@ type DMCache struct {
 }
 
 var sampleConfig = `
-	## Whether to report per-device stats or not
-	per_device = true
+  ## Whether to report per-device stats or not
+  per_device = true
 `
 
 func (c *DMCache) SampleConfig() string {
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index ed8b88c6809d3..b64b19056a4fd 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -6,6 +6,8 @@ import (
 	"strconv"
 	"strings"
 
+	"errors"
+
 	"github.com/influxdata/telegraf"
 )
 
@@ -31,10 +33,7 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 		return err
 	}
 
-	var total map[string]interface{}
-	if !c.PerDevice {
-		total = make(map[string]interface{})
-	}
+	total := make(map[string]interface{})
 
 	for _, s := range outputLines {
 		fields := make(map[string]interface{})
@@ -50,58 +49,86 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 		if c.PerDevice {
 			tags := map[string]string{"device": data["device"].(string)}
 			acc.AddFields(metricName, fields, tags)
-		} else {
-			aggregateStats(total, fields)
 		}
+		aggregateStats(total, fields)
 	}
 
-	if !c.PerDevice {
-		acc.AddFields(metricName, total, nil)
-	}
+	acc.AddFields(metricName, total, map[string]string{"device": "all"})
 
 	return nil
 }
 
-func parseDMSetupStatus(line string) (status map[string]interface{}, err error) {
-	defer func() {
-		if r := recover(); r != nil {
-			status = nil
-			err = r.(error)
-		}
-	}()
-
-	values := strings.Split(line, " ")
-	status = make(map[string]interface{})
+func parseDMSetupStatus(line string) (map[string]interface{}, error) {
+	var err error
+	status := make(map[string]interface{})
+	values := strings.Fields(line)
+	if len(values) < 15 {
+		return nil, errors.New("dmsetup status data have invalid format")
+	}
 
 	status["device"] = values[0][:len(values[0])-1]
-	status["length"] = toInt(values[2])
+	status["length"], err = strconv.Atoi(values[2])
+	if err != nil {
+		return nil, err
+	}
 	status["target"] = values[3]
-	status["metadata_blocksize"] = toInt(values[4])
-	status["metadata_used"] = toInt(strings.Split(values[5], "/")[0])
-	status["metadata_total"] = toInt(strings.Split(values[5], "/")[1])
-	status["cache_blocksize"] = toInt(values[6])
-	status["cache_used"] = toInt(strings.Split(values[7], "/")[0])
-	status["cache_total"] = toInt(strings.Split(values[7], "/")[1])
-	status["read_hits"] = toInt(values[8])
-	status["read_misses"] = toInt(values[9])
-	status["write_hits"] = toInt(values[10])
-	status["write_misses"] = toInt(values[11])
-	status["demotions"] = toInt(values[12])
-	status["promotions"] = toInt(values[13])
-	status["dirty"] = toInt(values[14])
+	status["metadata_blocksize"], err = strconv.Atoi(values[4])
+	if err != nil {
+		return nil, err
+	}
+	status["metadata_used"], err = strconv.Atoi(strings.Split(values[5], "/")[0])
+	if err != nil {
+		return nil, err
+	}
+	status["metadata_total"], err = strconv.Atoi(strings.Split(values[5], "/")[1])
+	if err != nil {
+		return nil, err
+	}
+	status["cache_blocksize"], err = strconv.Atoi(values[6])
+	if err != nil {
+		return nil, err
+	}
+	status["cache_used"], err = strconv.Atoi(strings.Split(values[7], "/")[0])
+	if err != nil {
+		return nil, err
+	}
+	status["cache_total"], err = strconv.Atoi(strings.Split(values[7], "/")[1])
+	if err != nil {
+		return nil, err
+	}
+	status["read_hits"], err = strconv.Atoi(values[8])
+	if err != nil {
+		return nil, err
+	}
+	status["read_misses"], err = strconv.Atoi(values[9])
+	if err != nil {
+		return nil, err
+	}
+	status["write_hits"], err = strconv.Atoi(values[10])
+	if err != nil {
+		return nil, err
+	}
+	status["write_misses"], err = strconv.Atoi(values[11])
+	if err != nil {
+		return nil, err
+	}
+	status["demotions"], err = strconv.Atoi(values[12])
+	if err != nil {
+		return nil, err
+	}
+	status["promotions"], err = strconv.Atoi(values[13])
+	if err != nil {
+		return nil, err
+	}
+	status["dirty"], err = strconv.Atoi(values[14])
+	if err != nil {
+		return nil, err
+	}
 	status["blocksize"] = 512
 
 	return status, nil
 }
 
-func toInt(s string) int {
-	i, err := strconv.Atoi(s)
-	if err != nil {
-		panic(err)
-	}
-	return i
-}
-
 func calculateSize(data map[string]interface{}, key string) (value int) {
 	if key == "metadata_free" {
 		value = data["metadata_total"].(int) - data["metadata_used"].(int)
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index 42d5072990802..d4295b38b268b 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -1,5 +1,3 @@
-// +build linux
-
 package dmcache
 
 import (
@@ -62,6 +60,25 @@ func TestDMCacheStats_1(t *testing.T) {
 		"dirty":         0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields2, tags2)
+
+	tags3 := map[string]string{
+		"device": "all",
+	}
+
+	fields3 := map[string]interface{}{
+		"metadata_used": 300523520,
+		"metadata_free": 11216781312,
+		"cache_used":    3538944,
+		"cache_free":    1716188741632,
+		"read_hits":     194314240,
+		"read_misses":   92461989888,
+		"write_hits":    21299200,
+		"write_misses":  34397618176,
+		"demotions":     0,
+		"promotions":    1835008,
+		"dirty":         0,
+	}
+	acc.AssertContainsTaggedFields(t, "dmcache", fields3, tags3)
 }
 
 var dmc2 = &DMCache{
@@ -75,7 +92,9 @@ func TestDMCacheStats_2(t *testing.T) {
 	err := dmc2.Gather(&acc)
 	require.NoError(t, err)
 
-	tags := map[string]string{}
+	tags := map[string]string{
+		"device": "all",
+	}
 
 	fields := map[string]interface{}{
 		"metadata_used": 300523520,

From f5e762f17115c2ec5f8fc943dd915ccfb8f87e22 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Mon, 3 Apr 2017 16:02:59 +0300
Subject: [PATCH 03/18] refactoring and new tests

---
 plugins/inputs/dmcache/dmcache.go       | 36 ++++++++-------
 plugins/inputs/dmcache/dmcache_linux.go | 23 +++++++---
 plugins/inputs/dmcache/dmcache_test.go  | 59 +++++++++++++++++++++++--
 3 files changed, 90 insertions(+), 28 deletions(-)

diff --git a/plugins/inputs/dmcache/dmcache.go b/plugins/inputs/dmcache/dmcache.go
index c36eed636af77..b933cc098b10a 100644
--- a/plugins/inputs/dmcache/dmcache.go
+++ b/plugins/inputs/dmcache/dmcache.go
@@ -9,8 +9,8 @@ import (
 )
 
 type DMCache struct {
-	PerDevice bool `toml:"per_device"`
-	rawStatus func() ([]string, error)
+	PerDevice        bool `toml:"per_device"`
+	getCurrentStatus func() ([]string, error)
 }
 
 var sampleConfig = `
@@ -26,24 +26,26 @@ func (c *DMCache) Description() string {
 	return "Provide a native collection for dmsetup based statistics for dm-cache"
 }
 
+func dmSetupStatus() ([]string, error) {
+	out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
+	if err != nil {
+		return nil, err
+	}
+	if string(out) == "No devices found\n" {
+		return []string{}, nil
+	}
+
+	outString := strings.TrimRight(string(out), "\n")
+	status := strings.Split(outString, "\n")
+
+	return status, nil
+}
+
 func init() {
 	inputs.Add("dmcache", func() telegraf.Input {
 		return &DMCache{
-			PerDevice: true,
-			rawStatus: func() ([]string, error) {
-				out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
-				if err != nil {
-					return nil, err
-				}
-				if string(out) == "No devices found\n" {
-					return nil, nil
-				}
-
-				status := strings.Split(string(out), "\n")
-				status = status[:len(status)-1] // removing last empty line
-
-				return status, nil
-			},
+			PerDevice:        true,
+			getCurrentStatus: dmSetupStatus,
 		}
 	})
 }
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index b64b19056a4fd..12fc2a0919401 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -28,7 +28,7 @@ var fieldNames = [...]string{
 }
 
 func (c *DMCache) Gather(acc telegraf.Accumulator) error {
-	outputLines, err := c.rawStatus()
+	outputLines, err := c.getCurrentStatus()
 	if err != nil {
 		return err
 	}
@@ -60,13 +60,14 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 
 func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 	var err error
+	parseError := errors.New("Output from dmsetup could not be parsed")
 	status := make(map[string]interface{})
 	values := strings.Fields(line)
 	if len(values) < 15 {
-		return nil, errors.New("dmsetup status data have invalid format")
+		return nil, parseError
 	}
 
-	status["device"] = values[0][:len(values[0])-1]
+	status["device"] = strings.TrimRight(values[0], ":")
 	status["length"], err = strconv.Atoi(values[2])
 	if err != nil {
 		return nil, err
@@ -76,11 +77,15 @@ func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 	if err != nil {
 		return nil, err
 	}
-	status["metadata_used"], err = strconv.Atoi(strings.Split(values[5], "/")[0])
+	metadata := strings.Split(values[5], "/")
+	if len(metadata) != 2 {
+		return nil, parseError
+	}
+	status["metadata_used"], err = strconv.Atoi(metadata[0])
 	if err != nil {
 		return nil, err
 	}
-	status["metadata_total"], err = strconv.Atoi(strings.Split(values[5], "/")[1])
+	status["metadata_total"], err = strconv.Atoi(metadata[1])
 	if err != nil {
 		return nil, err
 	}
@@ -88,11 +93,15 @@ func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 	if err != nil {
 		return nil, err
 	}
-	status["cache_used"], err = strconv.Atoi(strings.Split(values[7], "/")[0])
+	cache := strings.Split(values[7], "/")
+	if len(cache) != 2 {
+		return nil, parseError
+	}
+	status["cache_used"], err = strconv.Atoi(cache[0])
 	if err != nil {
 		return nil, err
 	}
-	status["cache_total"], err = strconv.Atoi(strings.Split(values[7], "/")[1])
+	status["cache_total"], err = strconv.Atoi(cache[1])
 	if err != nil {
 		return nil, err
 	}
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index d4295b38b268b..b35dc0eede9f3 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -1,6 +1,7 @@
 package dmcache
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/influxdata/telegraf/testutil"
@@ -15,8 +16,8 @@ func output2Devices() ([]string, error) {
 }
 
 var dmc1 = &DMCache{
-	PerDevice: true,
-	rawStatus: output2Devices,
+	PerDevice:        true,
+	getCurrentStatus: output2Devices,
 }
 
 func TestDMCacheStats_1(t *testing.T) {
@@ -82,8 +83,8 @@ func TestDMCacheStats_1(t *testing.T) {
 }
 
 var dmc2 = &DMCache{
-	PerDevice: false,
-	rawStatus: output2Devices,
+	PerDevice:        false,
+	getCurrentStatus: output2Devices,
 }
 
 func TestDMCacheStats_2(t *testing.T) {
@@ -111,3 +112,53 @@ func TestDMCacheStats_2(t *testing.T) {
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields, tags)
 }
+
+func outputNoDevices() ([]string, error) {
+	return []string{}, nil
+}
+
+var dmc3 = &DMCache{
+	PerDevice:        true,
+	getCurrentStatus: outputNoDevices,
+}
+
+func TestDMCacheStats_3(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc3.Gather(&acc)
+	require.NoError(t, err)
+}
+
+func noDMSetup() ([]string, error) {
+	return []string{}, errors.New("dmsetup doesn't exist")
+}
+
+var dmc4 = &DMCache{
+	PerDevice:        true,
+	getCurrentStatus: noDMSetup,
+}
+
+func TestDMCacheStats_4(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc4.Gather(&acc)
+	require.Error(t, err)
+}
+
+func badFormat() ([]string, error) {
+	return []string{
+		"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 ",
+	}, nil
+}
+
+var dmc5 = &DMCache{
+	PerDevice:        true,
+	getCurrentStatus: badFormat,
+}
+
+func TestDMCacheStats_5(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc5.Gather(&acc)
+	require.Error(t, err)
+}

From e5943bbc1f89a1cc4515e15222df3d99ece29aee Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Tue, 4 Apr 2017 17:40:52 +0300
Subject: [PATCH 04/18] removed synthesized values

---
 plugins/inputs/dmcache/dmcache_linux.go |  52 ++----------
 plugins/inputs/dmcache/dmcache_test.go  | 104 ++++++++++++++----------
 2 files changed, 68 insertions(+), 88 deletions(-)

diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index 12fc2a0919401..84cece5684ab7 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -13,20 +13,6 @@ import (
 
 const metricName = "dmcache"
 
-var fieldNames = [...]string{
-	"metadata_used",
-	"metadata_free",
-	"cache_used",
-	"cache_free",
-	"read_hits",
-	"read_misses",
-	"write_hits",
-	"write_misses",
-	"demotions",
-	"promotions",
-	"dirty",
-}
-
 func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	outputLines, err := c.getCurrentStatus()
 	if err != nil {
@@ -36,18 +22,13 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	total := make(map[string]interface{})
 
 	for _, s := range outputLines {
-		fields := make(map[string]interface{})
-		data, err := parseDMSetupStatus(s)
+		fields, err := parseDMSetupStatus(s)
 		if err != nil {
 			return err
 		}
 
-		for _, f := range fieldNames {
-			fields[f] = calculateSize(data, f)
-		}
-
 		if c.PerDevice {
-			tags := map[string]string{"device": data["device"].(string)}
+			tags := map[string]string{"device": fields["device"].(string)}
 			acc.AddFields(metricName, fields, tags)
 		}
 		aggregateStats(total, fields)
@@ -133,35 +114,18 @@ func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 	if err != nil {
 		return nil, err
 	}
-	status["blocksize"] = 512
 
 	return status, nil
 }
 
-func calculateSize(data map[string]interface{}, key string) (value int) {
-	if key == "metadata_free" {
-		value = data["metadata_total"].(int) - data["metadata_used"].(int)
-	} else if key == "cache_free" {
-		value = data["cache_total"].(int) - data["cache_used"].(int) - data["dirty"].(int)
-	} else {
-		value = data[key].(int)
-	}
-
-	if key == "metadata_free" || key == "metadata_used" {
-		value = value * data["blocksize"].(int) * data["metadata_blocksize"].(int)
-	} else {
-		value = value * data["blocksize"].(int) * data["cache_blocksize"].(int)
-	}
-
-	return
-}
-
 func aggregateStats(total, fields map[string]interface{}) {
 	for key, value := range fields {
-		if _, ok := total[key]; ok {
-			total[key] = total[key].(int) + value.(int)
-		} else {
-			total[key] = value.(int)
+		if _, ok := value.(int); ok {
+			if _, ok := total[key]; ok {
+				total[key] = total[key].(int) + value.(int)
+			} else {
+				total[key] = value.(int)
+			}
 		}
 	}
 }
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index b35dc0eede9f3..2c317f9da16b7 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -30,17 +30,22 @@ func TestDMCacheStats_1(t *testing.T) {
 		"device": "cs-1",
 	}
 	fields1 := map[string]interface{}{
-		"metadata_used": 4169728,
-		"metadata_free": 6144425984,
-		"cache_used":    1835008,
-		"cache_free":    121885163520,
-		"read_hits":     36438016,
-		"read_misses":   92443246592,
-		"write_hits":    3932160,
-		"write_misses":  12058624,
-		"demotions":     0,
-		"promotions":    1835008,
-		"dirty":         0,
+		"device":             "cs-1",
+		"length":             4883791872,
+		"target":             "cache",
+		"metadata_blocksize": 8,
+		"metadata_used":      1018,
+		"metadata_total":     1501122,
+		"cache_blocksize":    512,
+		"cache_used":         7,
+		"cache_total":        464962,
+		"read_hits":          139,
+		"read_misses":        352643,
+		"write_hits":         15,
+		"write_misses":       46,
+		"demotions":          0,
+		"promotions":         7,
+		"dirty":              0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields1, tags1)
 
@@ -48,17 +53,22 @@ func TestDMCacheStats_1(t *testing.T) {
 		"device": "cs-2",
 	}
 	fields2 := map[string]interface{}{
-		"metadata_used": 296353792,
-		"metadata_free": 5072355328,
-		"cache_used":    1703936,
-		"cache_free":    1594303578112,
-		"read_hits":     157876224,
-		"read_misses":   18743296,
-		"write_hits":    17367040,
-		"write_misses":  34385559552,
-		"demotions":     0,
-		"promotions":    0,
-		"dirty":         0,
+		"device":             "cs-2",
+		"length":             4294967296,
+		"target":             "cache",
+		"metadata_blocksize": 8,
+		"metadata_used":      72352,
+		"metadata_total":     1310720,
+		"cache_blocksize":    128,
+		"cache_used":         26,
+		"cache_total":        24327168,
+		"read_hits":          2409,
+		"read_misses":        286,
+		"write_hits":         265,
+		"write_misses":       524682,
+		"demotions":          0,
+		"promotions":         0,
+		"dirty":              0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields2, tags2)
 
@@ -67,17 +77,20 @@ func TestDMCacheStats_1(t *testing.T) {
 	}
 
 	fields3 := map[string]interface{}{
-		"metadata_used": 300523520,
-		"metadata_free": 11216781312,
-		"cache_used":    3538944,
-		"cache_free":    1716188741632,
-		"read_hits":     194314240,
-		"read_misses":   92461989888,
-		"write_hits":    21299200,
-		"write_misses":  34397618176,
-		"demotions":     0,
-		"promotions":    1835008,
-		"dirty":         0,
+		"length":             9178759168,
+		"metadata_blocksize": 16,
+		"metadata_used":      73370,
+		"metadata_total":     2811842,
+		"cache_blocksize":    640,
+		"cache_used":         33,
+		"cache_total":        24792130,
+		"read_hits":          2548,
+		"read_misses":        352929,
+		"write_hits":         280,
+		"write_misses":       524728,
+		"demotions":          0,
+		"promotions":         7,
+		"dirty":              0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields3, tags3)
 }
@@ -98,17 +111,20 @@ func TestDMCacheStats_2(t *testing.T) {
 	}
 
 	fields := map[string]interface{}{
-		"metadata_used": 300523520,
-		"metadata_free": 11216781312,
-		"cache_used":    3538944,
-		"cache_free":    1716188741632,
-		"read_hits":     194314240,
-		"read_misses":   92461989888,
-		"write_hits":    21299200,
-		"write_misses":  34397618176,
-		"demotions":     0,
-		"promotions":    1835008,
-		"dirty":         0,
+		"length":             9178759168,
+		"metadata_blocksize": 16,
+		"metadata_used":      73370,
+		"metadata_total":     2811842,
+		"cache_blocksize":    640,
+		"cache_used":         33,
+		"cache_total":        24792130,
+		"read_hits":          2548,
+		"read_misses":        352929,
+		"write_hits":         280,
+		"write_misses":       524728,
+		"demotions":          0,
+		"promotions":         7,
+		"dirty":              0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields, tags)
 }

From 5eadca576cb97190b946d6a4a42b6ed69aa44472 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Wed, 5 Apr 2017 11:25:19 +0300
Subject: [PATCH 05/18] updated readme

---
 plugins/inputs/dmcache/README.md | 36 ++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/plugins/inputs/dmcache/README.md b/plugins/inputs/dmcache/README.md
index ae4142e9aa2fa..8e45726860dc2 100644
--- a/plugins/inputs/dmcache/README.md
+++ b/plugins/inputs/dmcache/README.md
@@ -6,10 +6,42 @@ This plugin requires sudo, that is why you should setup and be sure that the tel
 
 `sudo /sbin/dmsetup status --target cache` is the full command that telegraf will run for debugging purposes.
 
-## Configuration
+### Configuration
 
-```
+```toml
 [[inputs.dmcache]]
   ## Whether to report per-device stats or not
   per_device = true
 ```
+
+### Measurements & Fields:
+
+- dmcache
+    - length
+    - target
+    - metadata_blocksize
+    - metadata_used
+    - metadata_total
+    - cache_blocksize
+    - cache_used
+    - cache_total
+    - read_hits
+    - read_misses
+    - write_hits
+    - write_misses
+    - demotions
+    - promotions
+    - dirty
+
+### Tags:
+
+- All measurements have the following tags:
+    - device
+
+### Example Output:
+
+```
+$ ./telegraf --test --config /etc/telegraf/telegraf.conf --input-filter dmcache
+* Plugin: inputs.dmcache, Collection 1
+> dmcache,bu=linux,cls=server,dc=colo,device=vg02-splunk_data_lv,env=production,host=hostname,sr=splunk_indexer,trd=false cache_free=0i,cache_used=1099511627776i,demotions=3265223720960i,dirty=0i,metadata_free=1060880384i,metadata_used=12861440i,promotions=3265223720960i,read_hits=995134034411520i,read_misses=916807089127424i,write_hits=195107267543040i,write_misses=563725346013184i 1491362011000000000
+```
\ No newline at end of file

From dc4c41943d96bb8f3078210a2b7a1c080a7fea54 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Wed, 5 Apr 2017 12:08:41 +0300
Subject: [PATCH 06/18] refactored map to struct

---
 plugins/inputs/dmcache/dmcache.go       |  18 ----
 plugins/inputs/dmcache/dmcache_linux.go | 135 ++++++++++++++++--------
 plugins/inputs/dmcache/dmcache_test.go  |   4 -
 3 files changed, 92 insertions(+), 65 deletions(-)

diff --git a/plugins/inputs/dmcache/dmcache.go b/plugins/inputs/dmcache/dmcache.go
index b933cc098b10a..25a398194edf8 100644
--- a/plugins/inputs/dmcache/dmcache.go
+++ b/plugins/inputs/dmcache/dmcache.go
@@ -1,9 +1,6 @@
 package dmcache
 
 import (
-	"os/exec"
-	"strings"
-
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
@@ -26,21 +23,6 @@ func (c *DMCache) Description() string {
 	return "Provide a native collection for dmsetup based statistics for dm-cache"
 }
 
-func dmSetupStatus() ([]string, error) {
-	out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
-	if err != nil {
-		return nil, err
-	}
-	if string(out) == "No devices found\n" {
-		return []string{}, nil
-	}
-
-	outString := strings.TrimRight(string(out), "\n")
-	status := strings.Split(outString, "\n")
-
-	return status, nil
-}
-
 func init() {
 	inputs.Add("dmcache", func() telegraf.Input {
 		return &DMCache{
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index 84cece5684ab7..8c698834b384f 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -3,6 +3,7 @@
 package dmcache
 
 import (
+	"os/exec"
 	"strconv"
 	"strings"
 
@@ -13,6 +14,25 @@ import (
 
 const metricName = "dmcache"
 
+type cacheStatus struct {
+	device            string
+	length            int
+	target            string
+	metadataBlocksize int
+	metadataUsed      int
+	metadataTotal     int
+	cacheBlocksize    int
+	cacheUsed         int
+	cacheTotal        int
+	readHits          int
+	readMisses        int
+	writeHits         int
+	writeMisses       int
+	demotions         int
+	promotions        int
+	dirty             int
+}
+
 func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	outputLines, err := c.getCurrentStatus()
 	if err != nil {
@@ -22,13 +42,29 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	total := make(map[string]interface{})
 
 	for _, s := range outputLines {
-		fields, err := parseDMSetupStatus(s)
+		status, err := parseDMSetupStatus(s)
 		if err != nil {
 			return err
 		}
 
+		fields := make(map[string]interface{})
+		fields["length"] = status.length
+		fields["metadata_blocksize"] = status.metadataBlocksize
+		fields["metadata_used"] = status.metadataUsed
+		fields["metadata_total"] = status.metadataTotal
+		fields["cache_blocksize"] = status.cacheBlocksize
+		fields["cache_used"] = status.cacheUsed
+		fields["cache_total"] = status.cacheTotal
+		fields["read_hits"] = status.readHits
+		fields["read_misses"] = status.readMisses
+		fields["write_hits"] = status.writeHits
+		fields["write_misses"] = status.writeMisses
+		fields["demotions"] = status.demotions
+		fields["promotions"] = status.promotions
+		fields["dirty"] = status.dirty
+
 		if c.PerDevice {
-			tags := map[string]string{"device": fields["device"].(string)}
+			tags := map[string]string{"device": status.device}
 			acc.AddFields(metricName, fields, tags)
 		}
 		aggregateStats(total, fields)
@@ -39,80 +75,80 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
-func parseDMSetupStatus(line string) (map[string]interface{}, error) {
+func parseDMSetupStatus(line string) (cacheStatus, error) {
 	var err error
 	parseError := errors.New("Output from dmsetup could not be parsed")
-	status := make(map[string]interface{})
+	status := cacheStatus{}
 	values := strings.Fields(line)
 	if len(values) < 15 {
-		return nil, parseError
+		return cacheStatus{}, parseError
 	}
 
-	status["device"] = strings.TrimRight(values[0], ":")
-	status["length"], err = strconv.Atoi(values[2])
+	status.device = strings.TrimRight(values[0], ":")
+	status.length, err = strconv.Atoi(values[2])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["target"] = values[3]
-	status["metadata_blocksize"], err = strconv.Atoi(values[4])
+	status.target = values[3]
+	status.metadataBlocksize, err = strconv.Atoi(values[4])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
 	metadata := strings.Split(values[5], "/")
 	if len(metadata) != 2 {
-		return nil, parseError
+		return cacheStatus{}, parseError
 	}
-	status["metadata_used"], err = strconv.Atoi(metadata[0])
+	status.metadataUsed, err = strconv.Atoi(metadata[0])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["metadata_total"], err = strconv.Atoi(metadata[1])
+	status.metadataTotal, err = strconv.Atoi(metadata[1])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["cache_blocksize"], err = strconv.Atoi(values[6])
+	status.cacheBlocksize, err = strconv.Atoi(values[6])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
 	cache := strings.Split(values[7], "/")
 	if len(cache) != 2 {
-		return nil, parseError
+		return cacheStatus{}, parseError
 	}
-	status["cache_used"], err = strconv.Atoi(cache[0])
+	status.cacheUsed, err = strconv.Atoi(cache[0])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["cache_total"], err = strconv.Atoi(cache[1])
+	status.cacheTotal, err = strconv.Atoi(cache[1])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["read_hits"], err = strconv.Atoi(values[8])
+	status.readHits, err = strconv.Atoi(values[8])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["read_misses"], err = strconv.Atoi(values[9])
+	status.readMisses, err = strconv.Atoi(values[9])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["write_hits"], err = strconv.Atoi(values[10])
+	status.writeHits, err = strconv.Atoi(values[10])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["write_misses"], err = strconv.Atoi(values[11])
+	status.writeMisses, err = strconv.Atoi(values[11])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["demotions"], err = strconv.Atoi(values[12])
+	status.demotions, err = strconv.Atoi(values[12])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["promotions"], err = strconv.Atoi(values[13])
+	status.promotions, err = strconv.Atoi(values[13])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["dirty"], err = strconv.Atoi(values[14])
+	status.dirty, err = strconv.Atoi(values[14])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
 
 	return status, nil
@@ -120,12 +156,25 @@ func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 
 func aggregateStats(total, fields map[string]interface{}) {
 	for key, value := range fields {
-		if _, ok := value.(int); ok {
-			if _, ok := total[key]; ok {
-				total[key] = total[key].(int) + value.(int)
-			} else {
-				total[key] = value.(int)
-			}
+		if _, ok := total[key]; ok {
+			total[key] = total[key].(int) + value.(int)
+		} else {
+			total[key] = value.(int)
 		}
 	}
 }
+
+func dmSetupStatus() ([]string, error) {
+	out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
+	if err != nil {
+		return nil, err
+	}
+	if string(out) == "No devices found\n" {
+		return []string{}, nil
+	}
+
+	outString := strings.TrimRight(string(out), "\n")
+	status := strings.Split(outString, "\n")
+
+	return status, nil
+}
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index 2c317f9da16b7..e30b91e2ee6f4 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -30,9 +30,7 @@ func TestDMCacheStats_1(t *testing.T) {
 		"device": "cs-1",
 	}
 	fields1 := map[string]interface{}{
-		"device":             "cs-1",
 		"length":             4883791872,
-		"target":             "cache",
 		"metadata_blocksize": 8,
 		"metadata_used":      1018,
 		"metadata_total":     1501122,
@@ -53,9 +51,7 @@ func TestDMCacheStats_1(t *testing.T) {
 		"device": "cs-2",
 	}
 	fields2 := map[string]interface{}{
-		"device":             "cs-2",
 		"length":             4294967296,
-		"target":             "cache",
 		"metadata_blocksize": 8,
 		"metadata_used":      72352,
 		"metadata_total":     1310720,

From b8d6d960c66f423cc833b1d46ebc7b13dabfff67 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Thu, 6 Apr 2017 15:54:26 +0300
Subject: [PATCH 07/18] refactoring: switching to fields at the last moment

---
 plugins/inputs/dmcache/README.md        |  4 +-
 plugins/inputs/dmcache/dmcache_linux.go | 66 ++++++++++++++-----------
 2 files changed, 40 insertions(+), 30 deletions(-)

diff --git a/plugins/inputs/dmcache/README.md b/plugins/inputs/dmcache/README.md
index 8e45726860dc2..536d3f518bcaa 100644
--- a/plugins/inputs/dmcache/README.md
+++ b/plugins/inputs/dmcache/README.md
@@ -43,5 +43,5 @@ This plugin requires sudo, that is why you should setup and be sure that the tel
 ```
 $ ./telegraf --test --config /etc/telegraf/telegraf.conf --input-filter dmcache
 * Plugin: inputs.dmcache, Collection 1
-> dmcache,bu=linux,cls=server,dc=colo,device=vg02-splunk_data_lv,env=production,host=hostname,sr=splunk_indexer,trd=false cache_free=0i,cache_used=1099511627776i,demotions=3265223720960i,dirty=0i,metadata_free=1060880384i,metadata_used=12861440i,promotions=3265223720960i,read_hits=995134034411520i,read_misses=916807089127424i,write_hits=195107267543040i,write_misses=563725346013184i 1491362011000000000
-```
\ No newline at end of file
+> dmcache,device=example cache_blocksize=0i,read_hits=995134034411520i,read_misses=916807089127424i,write_hits=195107267543040i,metadata_used=12861440i,write_misses=563725346013184i,promotions=3265223720960i,dirty=0i,metadata_blocksize=0i,cache_used=1099511627776ii,cache_total=0i,length=0i,metadata_total=1073741824i,demotions=3265223720960i 1491482035000000000
+```
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index 8c698834b384f..7ac1c96cae0f1 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -39,7 +39,7 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 		return err
 	}
 
-	total := make(map[string]interface{})
+	totalStatus := cacheStatus{}
 
 	for _, s := range outputLines {
 		status, err := parseDMSetupStatus(s)
@@ -47,30 +47,14 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 			return err
 		}
 
-		fields := make(map[string]interface{})
-		fields["length"] = status.length
-		fields["metadata_blocksize"] = status.metadataBlocksize
-		fields["metadata_used"] = status.metadataUsed
-		fields["metadata_total"] = status.metadataTotal
-		fields["cache_blocksize"] = status.cacheBlocksize
-		fields["cache_used"] = status.cacheUsed
-		fields["cache_total"] = status.cacheTotal
-		fields["read_hits"] = status.readHits
-		fields["read_misses"] = status.readMisses
-		fields["write_hits"] = status.writeHits
-		fields["write_misses"] = status.writeMisses
-		fields["demotions"] = status.demotions
-		fields["promotions"] = status.promotions
-		fields["dirty"] = status.dirty
-
 		if c.PerDevice {
 			tags := map[string]string{"device": status.device}
-			acc.AddFields(metricName, fields, tags)
+			acc.AddFields(metricName, toFields(status), tags)
 		}
-		aggregateStats(total, fields)
+		aggregateStats(&totalStatus, status)
 	}
 
-	acc.AddFields(metricName, total, map[string]string{"device": "all"})
+	acc.AddFields(metricName, toFields(totalStatus), map[string]string{"device": "all"})
 
 	return nil
 }
@@ -154,14 +138,40 @@ func parseDMSetupStatus(line string) (cacheStatus, error) {
 	return status, nil
 }
 
-func aggregateStats(total, fields map[string]interface{}) {
-	for key, value := range fields {
-		if _, ok := total[key]; ok {
-			total[key] = total[key].(int) + value.(int)
-		} else {
-			total[key] = value.(int)
-		}
-	}
+func aggregateStats(totalStatus *cacheStatus, status cacheStatus) {
+	totalStatus.length += status.length
+	totalStatus.metadataBlocksize += status.metadataBlocksize
+	totalStatus.metadataUsed += status.metadataUsed
+	totalStatus.metadataTotal += status.metadataTotal
+	totalStatus.cacheBlocksize += status.cacheBlocksize
+	totalStatus.cacheUsed += status.cacheUsed
+	totalStatus.cacheTotal += status.cacheTotal
+	totalStatus.readHits += status.readHits
+	totalStatus.readMisses += status.readMisses
+	totalStatus.writeHits += status.writeHits
+	totalStatus.writeMisses += status.writeMisses
+	totalStatus.demotions += status.demotions
+	totalStatus.promotions += status.promotions
+	totalStatus.dirty += status.dirty
+}
+
+func toFields(status cacheStatus) map[string]interface{} {
+	fields := make(map[string]interface{})
+	fields["length"] = status.length
+	fields["metadata_blocksize"] = status.metadataBlocksize
+	fields["metadata_used"] = status.metadataUsed
+	fields["metadata_total"] = status.metadataTotal
+	fields["cache_blocksize"] = status.cacheBlocksize
+	fields["cache_used"] = status.cacheUsed
+	fields["cache_total"] = status.cacheTotal
+	fields["read_hits"] = status.readHits
+	fields["read_misses"] = status.readMisses
+	fields["write_hits"] = status.writeHits
+	fields["write_misses"] = status.writeMisses
+	fields["demotions"] = status.demotions
+	fields["promotions"] = status.promotions
+	fields["dirty"] = status.dirty
+	return fields
 }
 
 func dmSetupStatus() ([]string, error) {

From 039d55853e459249b0de3975649f70a1abd77a9e Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Fri, 7 Apr 2017 11:49:27 +0300
Subject: [PATCH 08/18] tests refactoring

---
 plugins/inputs/dmcache/dmcache_test.go | 107 ++++++++++++-------------
 1 file changed, 50 insertions(+), 57 deletions(-)

diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index e30b91e2ee6f4..c5989c413d9c0 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -8,22 +8,25 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func output2Devices() ([]string, error) {
-	return []string{
+var (
+	measurement              = "dmcache"
+	badFormatOutput          = []string{"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 "}
+	good2DevicesFormatOutput = []string{
 		"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 15 46 0 7 0 1 writeback 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
 		"cs-2: 0 4294967296 cache 8 72352/1310720 128 26/24327168 2409 286 265 524682 0 0 0 1 writethrough 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
-	}, nil
-}
-
-var dmc1 = &DMCache{
-	PerDevice:        true,
-	getCurrentStatus: output2Devices,
-}
+	}
+)
 
-func TestDMCacheStats_1(t *testing.T) {
+func TestPerDeviceGoodOutput(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: true,
+		getCurrentStatus: func() ([]string, error) {
+			return good2DevicesFormatOutput, nil
+		},
+	}
 
-	err := dmc1.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.NoError(t, err)
 
 	tags1 := map[string]string{
@@ -45,7 +48,7 @@ func TestDMCacheStats_1(t *testing.T) {
 		"promotions":         7,
 		"dirty":              0,
 	}
-	acc.AssertContainsTaggedFields(t, "dmcache", fields1, tags1)
+	acc.AssertContainsTaggedFields(t, measurement, fields1, tags1)
 
 	tags2 := map[string]string{
 		"device": "cs-2",
@@ -66,7 +69,7 @@ func TestDMCacheStats_1(t *testing.T) {
 		"promotions":         0,
 		"dirty":              0,
 	}
-	acc.AssertContainsTaggedFields(t, "dmcache", fields2, tags2)
+	acc.AssertContainsTaggedFields(t, measurement, fields2, tags2)
 
 	tags3 := map[string]string{
 		"device": "all",
@@ -88,18 +91,19 @@ func TestDMCacheStats_1(t *testing.T) {
 		"promotions":         7,
 		"dirty":              0,
 	}
-	acc.AssertContainsTaggedFields(t, "dmcache", fields3, tags3)
+	acc.AssertContainsTaggedFields(t, measurement, fields3, tags3)
 }
 
-var dmc2 = &DMCache{
-	PerDevice:        false,
-	getCurrentStatus: output2Devices,
-}
-
-func TestDMCacheStats_2(t *testing.T) {
+func TestNotPerDeviceGoodOutput(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: false,
+		getCurrentStatus: func() ([]string, error) {
+			return good2DevicesFormatOutput, nil
+		},
+	}
 
-	err := dmc2.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.NoError(t, err)
 
 	tags := map[string]string{
@@ -122,55 +126,44 @@ func TestDMCacheStats_2(t *testing.T) {
 		"promotions":         7,
 		"dirty":              0,
 	}
-	acc.AssertContainsTaggedFields(t, "dmcache", fields, tags)
-}
-
-func outputNoDevices() ([]string, error) {
-	return []string{}, nil
-}
-
-var dmc3 = &DMCache{
-	PerDevice:        true,
-	getCurrentStatus: outputNoDevices,
+	acc.AssertContainsTaggedFields(t, measurement, fields, tags)
 }
 
-func TestDMCacheStats_3(t *testing.T) {
+func TestNoDevicesOutput(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: true,
+		getCurrentStatus: func() ([]string, error) {
+			return []string{}, nil
+		},
+	}
 
-	err := dmc3.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.NoError(t, err)
 }
 
-func noDMSetup() ([]string, error) {
-	return []string{}, errors.New("dmsetup doesn't exist")
-}
-
-var dmc4 = &DMCache{
-	PerDevice:        true,
-	getCurrentStatus: noDMSetup,
-}
-
-func TestDMCacheStats_4(t *testing.T) {
+func TestErrorDuringGettingStatus(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: true,
+		getCurrentStatus: func() ([]string, error) {
+			return nil, errors.New("dmsetup doesn't exist")
+		},
+	}
 
-	err := dmc4.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.Error(t, err)
 }
 
-func badFormat() ([]string, error) {
-	return []string{
-		"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 ",
-	}, nil
-}
-
-var dmc5 = &DMCache{
-	PerDevice:        true,
-	getCurrentStatus: badFormat,
-}
-
-func TestDMCacheStats_5(t *testing.T) {
+func TestBadFormatOfStatus(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: true,
+		getCurrentStatus: func() ([]string, error) {
+			return badFormatOutput, nil
+		},
+	}
 
-	err := dmc5.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.Error(t, err)
 }

From 2091671c22ec08f2fc1f148511db9ba9c9acbb31 Mon Sep 17 00:00:00 2001
From: Vladimir S <vlasad@gmail.com>
Date: Fri, 7 Apr 2017 13:13:06 +0300
Subject: [PATCH 09/18] Update CHANGELOG.md

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 333963bd59f85..46d8b57d5b1d6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -64,6 +64,7 @@ be deprecated eventually.
 - [#2587](https://github.com/influxdata/telegraf/pull/2587): Add json timestamp units configurability
 - [#2597](https://github.com/influxdata/telegraf/issues/2597): Add support for Linux sysctl-fs metrics.
 - [#2425](https://github.com/influxdata/telegraf/pull/2425): Support to include/exclude docker container labels as tags
+- [#1667](https://github.com/influxdata/telegraf/pull/1667): dmcache input plugin
 
 ### Bugfixes
 

From edd631a585f1694ea799b84c6f3f1fd84a3e8651 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Wed, 24 Aug 2016 22:41:53 +0300
Subject: [PATCH 10/18] Add dmcache input plugin

---
 plugins/inputs/all/all.go                  |   1 +
 plugins/inputs/dmcache/README.md           |  11 ++
 plugins/inputs/dmcache/dmcache.go          |  49 ++++++++
 plugins/inputs/dmcache/dmcache_linux.go    | 131 +++++++++++++++++++++
 plugins/inputs/dmcache/dmcache_notlinux.go |  11 ++
 plugins/inputs/dmcache/dmcache_test.go     |  94 +++++++++++++++
 6 files changed, 297 insertions(+)
 create mode 100644 plugins/inputs/dmcache/README.md
 create mode 100644 plugins/inputs/dmcache/dmcache.go
 create mode 100644 plugins/inputs/dmcache/dmcache_linux.go
 create mode 100644 plugins/inputs/dmcache/dmcache_notlinux.go
 create mode 100644 plugins/inputs/dmcache/dmcache_test.go

diff --git a/plugins/inputs/all/all.go b/plugins/inputs/all/all.go
index a9147c53ed153..983179e903bdc 100644
--- a/plugins/inputs/all/all.go
+++ b/plugins/inputs/all/all.go
@@ -15,6 +15,7 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/inputs/couchbase"
 	_ "github.com/influxdata/telegraf/plugins/inputs/couchdb"
 	_ "github.com/influxdata/telegraf/plugins/inputs/disque"
+	_ "github.com/influxdata/telegraf/plugins/inputs/dmcache"
 	_ "github.com/influxdata/telegraf/plugins/inputs/dns_query"
 	_ "github.com/influxdata/telegraf/plugins/inputs/docker"
 	_ "github.com/influxdata/telegraf/plugins/inputs/dovecot"
diff --git a/plugins/inputs/dmcache/README.md b/plugins/inputs/dmcache/README.md
new file mode 100644
index 0000000000000..87931376e0e18
--- /dev/null
+++ b/plugins/inputs/dmcache/README.md
@@ -0,0 +1,11 @@
+# DMCache Input Plugin
+
+This plugin provide a native collection for dmsetup based statistics for dm-cache
+
+## Configuration
+
+```
+[[inputs.dmcache]]
+## Whether to report per-device stats or not
+	per_device = true
+```
diff --git a/plugins/inputs/dmcache/dmcache.go b/plugins/inputs/dmcache/dmcache.go
new file mode 100644
index 0000000000000..bfcb6dadcb751
--- /dev/null
+++ b/plugins/inputs/dmcache/dmcache.go
@@ -0,0 +1,49 @@
+package dmcache
+
+import (
+	"os/exec"
+	"strings"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+type DMCache struct {
+	PerDevice bool `toml:"per_device"`
+	rawStatus func() ([]string, error)
+}
+
+var sampleConfig = `
+	## Whether to report per-device stats or not
+	per_device = true
+`
+
+func (c *DMCache) SampleConfig() string {
+	return sampleConfig
+}
+
+func (c *DMCache) Description() string {
+	return "Provide a native collection for dmsetup based statistics for dm-cache"
+}
+
+func init() {
+	inputs.Add("dmcache", func() telegraf.Input {
+		return &DMCache{
+			PerDevice: true,
+			rawStatus: func() ([]string, error) {
+				out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
+				if err != nil {
+					return nil, err
+				}
+				if string(out) == "No devices found\n" {
+					return nil, nil
+				}
+
+				status := strings.Split(string(out), "\n")
+				status = status[:len(status)-1] // removing last empty line
+
+				return status, nil
+			},
+		}
+	})
+}
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
new file mode 100644
index 0000000000000..ed8b88c6809d3
--- /dev/null
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -0,0 +1,131 @@
+// +build linux
+
+package dmcache
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/influxdata/telegraf"
+)
+
+const metricName = "dmcache"
+
+var fieldNames = [...]string{
+	"metadata_used",
+	"metadata_free",
+	"cache_used",
+	"cache_free",
+	"read_hits",
+	"read_misses",
+	"write_hits",
+	"write_misses",
+	"demotions",
+	"promotions",
+	"dirty",
+}
+
+func (c *DMCache) Gather(acc telegraf.Accumulator) error {
+	outputLines, err := c.rawStatus()
+	if err != nil {
+		return err
+	}
+
+	var total map[string]interface{}
+	if !c.PerDevice {
+		total = make(map[string]interface{})
+	}
+
+	for _, s := range outputLines {
+		fields := make(map[string]interface{})
+		data, err := parseDMSetupStatus(s)
+		if err != nil {
+			return err
+		}
+
+		for _, f := range fieldNames {
+			fields[f] = calculateSize(data, f)
+		}
+
+		if c.PerDevice {
+			tags := map[string]string{"device": data["device"].(string)}
+			acc.AddFields(metricName, fields, tags)
+		} else {
+			aggregateStats(total, fields)
+		}
+	}
+
+	if !c.PerDevice {
+		acc.AddFields(metricName, total, nil)
+	}
+
+	return nil
+}
+
+func parseDMSetupStatus(line string) (status map[string]interface{}, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			status = nil
+			err = r.(error)
+		}
+	}()
+
+	values := strings.Split(line, " ")
+	status = make(map[string]interface{})
+
+	status["device"] = values[0][:len(values[0])-1]
+	status["length"] = toInt(values[2])
+	status["target"] = values[3]
+	status["metadata_blocksize"] = toInt(values[4])
+	status["metadata_used"] = toInt(strings.Split(values[5], "/")[0])
+	status["metadata_total"] = toInt(strings.Split(values[5], "/")[1])
+	status["cache_blocksize"] = toInt(values[6])
+	status["cache_used"] = toInt(strings.Split(values[7], "/")[0])
+	status["cache_total"] = toInt(strings.Split(values[7], "/")[1])
+	status["read_hits"] = toInt(values[8])
+	status["read_misses"] = toInt(values[9])
+	status["write_hits"] = toInt(values[10])
+	status["write_misses"] = toInt(values[11])
+	status["demotions"] = toInt(values[12])
+	status["promotions"] = toInt(values[13])
+	status["dirty"] = toInt(values[14])
+	status["blocksize"] = 512
+
+	return status, nil
+}
+
+func toInt(s string) int {
+	i, err := strconv.Atoi(s)
+	if err != nil {
+		panic(err)
+	}
+	return i
+}
+
+func calculateSize(data map[string]interface{}, key string) (value int) {
+	if key == "metadata_free" {
+		value = data["metadata_total"].(int) - data["metadata_used"].(int)
+	} else if key == "cache_free" {
+		value = data["cache_total"].(int) - data["cache_used"].(int) - data["dirty"].(int)
+	} else {
+		value = data[key].(int)
+	}
+
+	if key == "metadata_free" || key == "metadata_used" {
+		value = value * data["blocksize"].(int) * data["metadata_blocksize"].(int)
+	} else {
+		value = value * data["blocksize"].(int) * data["cache_blocksize"].(int)
+	}
+
+	return
+}
+
+func aggregateStats(total, fields map[string]interface{}) {
+	for key, value := range fields {
+		if _, ok := total[key]; ok {
+			total[key] = total[key].(int) + value.(int)
+		} else {
+			total[key] = value.(int)
+		}
+	}
+}
diff --git a/plugins/inputs/dmcache/dmcache_notlinux.go b/plugins/inputs/dmcache/dmcache_notlinux.go
new file mode 100644
index 0000000000000..478c2f163e4dc
--- /dev/null
+++ b/plugins/inputs/dmcache/dmcache_notlinux.go
@@ -0,0 +1,11 @@
+// +build !linux
+
+package dmcache
+
+import (
+	"github.com/influxdata/telegraf"
+)
+
+func (c *DMCache) Gather(acc telegraf.Accumulator) error {
+	return nil
+}
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
new file mode 100644
index 0000000000000..42d5072990802
--- /dev/null
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -0,0 +1,94 @@
+// +build linux
+
+package dmcache
+
+import (
+	"testing"
+
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/require"
+)
+
+func output2Devices() ([]string, error) {
+	return []string{
+		"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 15 46 0 7 0 1 writeback 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
+		"cs-2: 0 4294967296 cache 8 72352/1310720 128 26/24327168 2409 286 265 524682 0 0 0 1 writethrough 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
+	}, nil
+}
+
+var dmc1 = &DMCache{
+	PerDevice: true,
+	rawStatus: output2Devices,
+}
+
+func TestDMCacheStats_1(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc1.Gather(&acc)
+	require.NoError(t, err)
+
+	tags1 := map[string]string{
+		"device": "cs-1",
+	}
+	fields1 := map[string]interface{}{
+		"metadata_used": 4169728,
+		"metadata_free": 6144425984,
+		"cache_used":    1835008,
+		"cache_free":    121885163520,
+		"read_hits":     36438016,
+		"read_misses":   92443246592,
+		"write_hits":    3932160,
+		"write_misses":  12058624,
+		"demotions":     0,
+		"promotions":    1835008,
+		"dirty":         0,
+	}
+	acc.AssertContainsTaggedFields(t, "dmcache", fields1, tags1)
+
+	tags2 := map[string]string{
+		"device": "cs-2",
+	}
+	fields2 := map[string]interface{}{
+		"metadata_used": 296353792,
+		"metadata_free": 5072355328,
+		"cache_used":    1703936,
+		"cache_free":    1594303578112,
+		"read_hits":     157876224,
+		"read_misses":   18743296,
+		"write_hits":    17367040,
+		"write_misses":  34385559552,
+		"demotions":     0,
+		"promotions":    0,
+		"dirty":         0,
+	}
+	acc.AssertContainsTaggedFields(t, "dmcache", fields2, tags2)
+}
+
+var dmc2 = &DMCache{
+	PerDevice: false,
+	rawStatus: output2Devices,
+}
+
+func TestDMCacheStats_2(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc2.Gather(&acc)
+	require.NoError(t, err)
+
+	tags := map[string]string{}
+
+	fields := map[string]interface{}{
+		"metadata_used": 300523520,
+		"metadata_free": 11216781312,
+		"cache_used":    3538944,
+		"cache_free":    1716188741632,
+		"read_hits":     194314240,
+		"read_misses":   92461989888,
+		"write_hits":    21299200,
+		"write_misses":  34397618176,
+		"demotions":     0,
+		"promotions":    1835008,
+		"dirty":         0,
+	}
+	acc.AssertContainsTaggedFields(t, "dmcache", fields, tags)
+}

From 525fc05915918ae4edfca12c1d8225e0032a1e72 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Wed, 29 Mar 2017 12:19:25 +0300
Subject: [PATCH 11/18] dmcache refactoring

---
 plugins/inputs/dmcache/README.md        |  10 ++-
 plugins/inputs/dmcache/dmcache.go       |   4 +-
 plugins/inputs/dmcache/dmcache_linux.go | 109 +++++++++++++++---------
 plugins/inputs/dmcache/dmcache_test.go  |  25 +++++-
 4 files changed, 99 insertions(+), 49 deletions(-)

diff --git a/plugins/inputs/dmcache/README.md b/plugins/inputs/dmcache/README.md
index 87931376e0e18..ae4142e9aa2fa 100644
--- a/plugins/inputs/dmcache/README.md
+++ b/plugins/inputs/dmcache/README.md
@@ -1,11 +1,15 @@
 # DMCache Input Plugin
 
-This plugin provide a native collection for dmsetup based statistics for dm-cache
+This plugin provide a native collection for dmsetup based statistics for dm-cache.
+
+This plugin requires sudo, that is why you should setup and be sure that the telegraf is able to execute sudo without a password.
+
+`sudo /sbin/dmsetup status --target cache` is the full command that telegraf will run for debugging purposes.
 
 ## Configuration
 
 ```
 [[inputs.dmcache]]
-## Whether to report per-device stats or not
-	per_device = true
+  ## Whether to report per-device stats or not
+  per_device = true
 ```
diff --git a/plugins/inputs/dmcache/dmcache.go b/plugins/inputs/dmcache/dmcache.go
index bfcb6dadcb751..c36eed636af77 100644
--- a/plugins/inputs/dmcache/dmcache.go
+++ b/plugins/inputs/dmcache/dmcache.go
@@ -14,8 +14,8 @@ type DMCache struct {
 }
 
 var sampleConfig = `
-	## Whether to report per-device stats or not
-	per_device = true
+  ## Whether to report per-device stats or not
+  per_device = true
 `
 
 func (c *DMCache) SampleConfig() string {
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index ed8b88c6809d3..b64b19056a4fd 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -6,6 +6,8 @@ import (
 	"strconv"
 	"strings"
 
+	"errors"
+
 	"github.com/influxdata/telegraf"
 )
 
@@ -31,10 +33,7 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 		return err
 	}
 
-	var total map[string]interface{}
-	if !c.PerDevice {
-		total = make(map[string]interface{})
-	}
+	total := make(map[string]interface{})
 
 	for _, s := range outputLines {
 		fields := make(map[string]interface{})
@@ -50,58 +49,86 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 		if c.PerDevice {
 			tags := map[string]string{"device": data["device"].(string)}
 			acc.AddFields(metricName, fields, tags)
-		} else {
-			aggregateStats(total, fields)
 		}
+		aggregateStats(total, fields)
 	}
 
-	if !c.PerDevice {
-		acc.AddFields(metricName, total, nil)
-	}
+	acc.AddFields(metricName, total, map[string]string{"device": "all"})
 
 	return nil
 }
 
-func parseDMSetupStatus(line string) (status map[string]interface{}, err error) {
-	defer func() {
-		if r := recover(); r != nil {
-			status = nil
-			err = r.(error)
-		}
-	}()
-
-	values := strings.Split(line, " ")
-	status = make(map[string]interface{})
+func parseDMSetupStatus(line string) (map[string]interface{}, error) {
+	var err error
+	status := make(map[string]interface{})
+	values := strings.Fields(line)
+	if len(values) < 15 {
+		return nil, errors.New("dmsetup status data have invalid format")
+	}
 
 	status["device"] = values[0][:len(values[0])-1]
-	status["length"] = toInt(values[2])
+	status["length"], err = strconv.Atoi(values[2])
+	if err != nil {
+		return nil, err
+	}
 	status["target"] = values[3]
-	status["metadata_blocksize"] = toInt(values[4])
-	status["metadata_used"] = toInt(strings.Split(values[5], "/")[0])
-	status["metadata_total"] = toInt(strings.Split(values[5], "/")[1])
-	status["cache_blocksize"] = toInt(values[6])
-	status["cache_used"] = toInt(strings.Split(values[7], "/")[0])
-	status["cache_total"] = toInt(strings.Split(values[7], "/")[1])
-	status["read_hits"] = toInt(values[8])
-	status["read_misses"] = toInt(values[9])
-	status["write_hits"] = toInt(values[10])
-	status["write_misses"] = toInt(values[11])
-	status["demotions"] = toInt(values[12])
-	status["promotions"] = toInt(values[13])
-	status["dirty"] = toInt(values[14])
+	status["metadata_blocksize"], err = strconv.Atoi(values[4])
+	if err != nil {
+		return nil, err
+	}
+	status["metadata_used"], err = strconv.Atoi(strings.Split(values[5], "/")[0])
+	if err != nil {
+		return nil, err
+	}
+	status["metadata_total"], err = strconv.Atoi(strings.Split(values[5], "/")[1])
+	if err != nil {
+		return nil, err
+	}
+	status["cache_blocksize"], err = strconv.Atoi(values[6])
+	if err != nil {
+		return nil, err
+	}
+	status["cache_used"], err = strconv.Atoi(strings.Split(values[7], "/")[0])
+	if err != nil {
+		return nil, err
+	}
+	status["cache_total"], err = strconv.Atoi(strings.Split(values[7], "/")[1])
+	if err != nil {
+		return nil, err
+	}
+	status["read_hits"], err = strconv.Atoi(values[8])
+	if err != nil {
+		return nil, err
+	}
+	status["read_misses"], err = strconv.Atoi(values[9])
+	if err != nil {
+		return nil, err
+	}
+	status["write_hits"], err = strconv.Atoi(values[10])
+	if err != nil {
+		return nil, err
+	}
+	status["write_misses"], err = strconv.Atoi(values[11])
+	if err != nil {
+		return nil, err
+	}
+	status["demotions"], err = strconv.Atoi(values[12])
+	if err != nil {
+		return nil, err
+	}
+	status["promotions"], err = strconv.Atoi(values[13])
+	if err != nil {
+		return nil, err
+	}
+	status["dirty"], err = strconv.Atoi(values[14])
+	if err != nil {
+		return nil, err
+	}
 	status["blocksize"] = 512
 
 	return status, nil
 }
 
-func toInt(s string) int {
-	i, err := strconv.Atoi(s)
-	if err != nil {
-		panic(err)
-	}
-	return i
-}
-
 func calculateSize(data map[string]interface{}, key string) (value int) {
 	if key == "metadata_free" {
 		value = data["metadata_total"].(int) - data["metadata_used"].(int)
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index 42d5072990802..d4295b38b268b 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -1,5 +1,3 @@
-// +build linux
-
 package dmcache
 
 import (
@@ -62,6 +60,25 @@ func TestDMCacheStats_1(t *testing.T) {
 		"dirty":         0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields2, tags2)
+
+	tags3 := map[string]string{
+		"device": "all",
+	}
+
+	fields3 := map[string]interface{}{
+		"metadata_used": 300523520,
+		"metadata_free": 11216781312,
+		"cache_used":    3538944,
+		"cache_free":    1716188741632,
+		"read_hits":     194314240,
+		"read_misses":   92461989888,
+		"write_hits":    21299200,
+		"write_misses":  34397618176,
+		"demotions":     0,
+		"promotions":    1835008,
+		"dirty":         0,
+	}
+	acc.AssertContainsTaggedFields(t, "dmcache", fields3, tags3)
 }
 
 var dmc2 = &DMCache{
@@ -75,7 +92,9 @@ func TestDMCacheStats_2(t *testing.T) {
 	err := dmc2.Gather(&acc)
 	require.NoError(t, err)
 
-	tags := map[string]string{}
+	tags := map[string]string{
+		"device": "all",
+	}
 
 	fields := map[string]interface{}{
 		"metadata_used": 300523520,

From c7a7ab68e25b857cf14edd706bff77edb31cb152 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Mon, 3 Apr 2017 16:02:59 +0300
Subject: [PATCH 12/18] refactoring and new tests

---
 plugins/inputs/dmcache/dmcache.go       | 36 ++++++++-------
 plugins/inputs/dmcache/dmcache_linux.go | 23 +++++++---
 plugins/inputs/dmcache/dmcache_test.go  | 59 +++++++++++++++++++++++--
 3 files changed, 90 insertions(+), 28 deletions(-)

diff --git a/plugins/inputs/dmcache/dmcache.go b/plugins/inputs/dmcache/dmcache.go
index c36eed636af77..b933cc098b10a 100644
--- a/plugins/inputs/dmcache/dmcache.go
+++ b/plugins/inputs/dmcache/dmcache.go
@@ -9,8 +9,8 @@ import (
 )
 
 type DMCache struct {
-	PerDevice bool `toml:"per_device"`
-	rawStatus func() ([]string, error)
+	PerDevice        bool `toml:"per_device"`
+	getCurrentStatus func() ([]string, error)
 }
 
 var sampleConfig = `
@@ -26,24 +26,26 @@ func (c *DMCache) Description() string {
 	return "Provide a native collection for dmsetup based statistics for dm-cache"
 }
 
+func dmSetupStatus() ([]string, error) {
+	out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
+	if err != nil {
+		return nil, err
+	}
+	if string(out) == "No devices found\n" {
+		return []string{}, nil
+	}
+
+	outString := strings.TrimRight(string(out), "\n")
+	status := strings.Split(outString, "\n")
+
+	return status, nil
+}
+
 func init() {
 	inputs.Add("dmcache", func() telegraf.Input {
 		return &DMCache{
-			PerDevice: true,
-			rawStatus: func() ([]string, error) {
-				out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
-				if err != nil {
-					return nil, err
-				}
-				if string(out) == "No devices found\n" {
-					return nil, nil
-				}
-
-				status := strings.Split(string(out), "\n")
-				status = status[:len(status)-1] // removing last empty line
-
-				return status, nil
-			},
+			PerDevice:        true,
+			getCurrentStatus: dmSetupStatus,
 		}
 	})
 }
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index b64b19056a4fd..12fc2a0919401 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -28,7 +28,7 @@ var fieldNames = [...]string{
 }
 
 func (c *DMCache) Gather(acc telegraf.Accumulator) error {
-	outputLines, err := c.rawStatus()
+	outputLines, err := c.getCurrentStatus()
 	if err != nil {
 		return err
 	}
@@ -60,13 +60,14 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 
 func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 	var err error
+	parseError := errors.New("Output from dmsetup could not be parsed")
 	status := make(map[string]interface{})
 	values := strings.Fields(line)
 	if len(values) < 15 {
-		return nil, errors.New("dmsetup status data have invalid format")
+		return nil, parseError
 	}
 
-	status["device"] = values[0][:len(values[0])-1]
+	status["device"] = strings.TrimRight(values[0], ":")
 	status["length"], err = strconv.Atoi(values[2])
 	if err != nil {
 		return nil, err
@@ -76,11 +77,15 @@ func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 	if err != nil {
 		return nil, err
 	}
-	status["metadata_used"], err = strconv.Atoi(strings.Split(values[5], "/")[0])
+	metadata := strings.Split(values[5], "/")
+	if len(metadata) != 2 {
+		return nil, parseError
+	}
+	status["metadata_used"], err = strconv.Atoi(metadata[0])
 	if err != nil {
 		return nil, err
 	}
-	status["metadata_total"], err = strconv.Atoi(strings.Split(values[5], "/")[1])
+	status["metadata_total"], err = strconv.Atoi(metadata[1])
 	if err != nil {
 		return nil, err
 	}
@@ -88,11 +93,15 @@ func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 	if err != nil {
 		return nil, err
 	}
-	status["cache_used"], err = strconv.Atoi(strings.Split(values[7], "/")[0])
+	cache := strings.Split(values[7], "/")
+	if len(cache) != 2 {
+		return nil, parseError
+	}
+	status["cache_used"], err = strconv.Atoi(cache[0])
 	if err != nil {
 		return nil, err
 	}
-	status["cache_total"], err = strconv.Atoi(strings.Split(values[7], "/")[1])
+	status["cache_total"], err = strconv.Atoi(cache[1])
 	if err != nil {
 		return nil, err
 	}
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index d4295b38b268b..b35dc0eede9f3 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -1,6 +1,7 @@
 package dmcache
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/influxdata/telegraf/testutil"
@@ -15,8 +16,8 @@ func output2Devices() ([]string, error) {
 }
 
 var dmc1 = &DMCache{
-	PerDevice: true,
-	rawStatus: output2Devices,
+	PerDevice:        true,
+	getCurrentStatus: output2Devices,
 }
 
 func TestDMCacheStats_1(t *testing.T) {
@@ -82,8 +83,8 @@ func TestDMCacheStats_1(t *testing.T) {
 }
 
 var dmc2 = &DMCache{
-	PerDevice: false,
-	rawStatus: output2Devices,
+	PerDevice:        false,
+	getCurrentStatus: output2Devices,
 }
 
 func TestDMCacheStats_2(t *testing.T) {
@@ -111,3 +112,53 @@ func TestDMCacheStats_2(t *testing.T) {
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields, tags)
 }
+
+func outputNoDevices() ([]string, error) {
+	return []string{}, nil
+}
+
+var dmc3 = &DMCache{
+	PerDevice:        true,
+	getCurrentStatus: outputNoDevices,
+}
+
+func TestDMCacheStats_3(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc3.Gather(&acc)
+	require.NoError(t, err)
+}
+
+func noDMSetup() ([]string, error) {
+	return []string{}, errors.New("dmsetup doesn't exist")
+}
+
+var dmc4 = &DMCache{
+	PerDevice:        true,
+	getCurrentStatus: noDMSetup,
+}
+
+func TestDMCacheStats_4(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc4.Gather(&acc)
+	require.Error(t, err)
+}
+
+func badFormat() ([]string, error) {
+	return []string{
+		"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 ",
+	}, nil
+}
+
+var dmc5 = &DMCache{
+	PerDevice:        true,
+	getCurrentStatus: badFormat,
+}
+
+func TestDMCacheStats_5(t *testing.T) {
+	var acc testutil.Accumulator
+
+	err := dmc5.Gather(&acc)
+	require.Error(t, err)
+}

From b696320ff0b702aeec19c55863cb5ec8daae8ad3 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Tue, 4 Apr 2017 17:40:52 +0300
Subject: [PATCH 13/18] removed synthesized values

---
 plugins/inputs/dmcache/dmcache_linux.go |  52 ++----------
 plugins/inputs/dmcache/dmcache_test.go  | 104 ++++++++++++++----------
 2 files changed, 68 insertions(+), 88 deletions(-)

diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index 12fc2a0919401..84cece5684ab7 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -13,20 +13,6 @@ import (
 
 const metricName = "dmcache"
 
-var fieldNames = [...]string{
-	"metadata_used",
-	"metadata_free",
-	"cache_used",
-	"cache_free",
-	"read_hits",
-	"read_misses",
-	"write_hits",
-	"write_misses",
-	"demotions",
-	"promotions",
-	"dirty",
-}
-
 func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	outputLines, err := c.getCurrentStatus()
 	if err != nil {
@@ -36,18 +22,13 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	total := make(map[string]interface{})
 
 	for _, s := range outputLines {
-		fields := make(map[string]interface{})
-		data, err := parseDMSetupStatus(s)
+		fields, err := parseDMSetupStatus(s)
 		if err != nil {
 			return err
 		}
 
-		for _, f := range fieldNames {
-			fields[f] = calculateSize(data, f)
-		}
-
 		if c.PerDevice {
-			tags := map[string]string{"device": data["device"].(string)}
+			tags := map[string]string{"device": fields["device"].(string)}
 			acc.AddFields(metricName, fields, tags)
 		}
 		aggregateStats(total, fields)
@@ -133,35 +114,18 @@ func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 	if err != nil {
 		return nil, err
 	}
-	status["blocksize"] = 512
 
 	return status, nil
 }
 
-func calculateSize(data map[string]interface{}, key string) (value int) {
-	if key == "metadata_free" {
-		value = data["metadata_total"].(int) - data["metadata_used"].(int)
-	} else if key == "cache_free" {
-		value = data["cache_total"].(int) - data["cache_used"].(int) - data["dirty"].(int)
-	} else {
-		value = data[key].(int)
-	}
-
-	if key == "metadata_free" || key == "metadata_used" {
-		value = value * data["blocksize"].(int) * data["metadata_blocksize"].(int)
-	} else {
-		value = value * data["blocksize"].(int) * data["cache_blocksize"].(int)
-	}
-
-	return
-}
-
 func aggregateStats(total, fields map[string]interface{}) {
 	for key, value := range fields {
-		if _, ok := total[key]; ok {
-			total[key] = total[key].(int) + value.(int)
-		} else {
-			total[key] = value.(int)
+		if _, ok := value.(int); ok {
+			if _, ok := total[key]; ok {
+				total[key] = total[key].(int) + value.(int)
+			} else {
+				total[key] = value.(int)
+			}
 		}
 	}
 }
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index b35dc0eede9f3..2c317f9da16b7 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -30,17 +30,22 @@ func TestDMCacheStats_1(t *testing.T) {
 		"device": "cs-1",
 	}
 	fields1 := map[string]interface{}{
-		"metadata_used": 4169728,
-		"metadata_free": 6144425984,
-		"cache_used":    1835008,
-		"cache_free":    121885163520,
-		"read_hits":     36438016,
-		"read_misses":   92443246592,
-		"write_hits":    3932160,
-		"write_misses":  12058624,
-		"demotions":     0,
-		"promotions":    1835008,
-		"dirty":         0,
+		"device":             "cs-1",
+		"length":             4883791872,
+		"target":             "cache",
+		"metadata_blocksize": 8,
+		"metadata_used":      1018,
+		"metadata_total":     1501122,
+		"cache_blocksize":    512,
+		"cache_used":         7,
+		"cache_total":        464962,
+		"read_hits":          139,
+		"read_misses":        352643,
+		"write_hits":         15,
+		"write_misses":       46,
+		"demotions":          0,
+		"promotions":         7,
+		"dirty":              0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields1, tags1)
 
@@ -48,17 +53,22 @@ func TestDMCacheStats_1(t *testing.T) {
 		"device": "cs-2",
 	}
 	fields2 := map[string]interface{}{
-		"metadata_used": 296353792,
-		"metadata_free": 5072355328,
-		"cache_used":    1703936,
-		"cache_free":    1594303578112,
-		"read_hits":     157876224,
-		"read_misses":   18743296,
-		"write_hits":    17367040,
-		"write_misses":  34385559552,
-		"demotions":     0,
-		"promotions":    0,
-		"dirty":         0,
+		"device":             "cs-2",
+		"length":             4294967296,
+		"target":             "cache",
+		"metadata_blocksize": 8,
+		"metadata_used":      72352,
+		"metadata_total":     1310720,
+		"cache_blocksize":    128,
+		"cache_used":         26,
+		"cache_total":        24327168,
+		"read_hits":          2409,
+		"read_misses":        286,
+		"write_hits":         265,
+		"write_misses":       524682,
+		"demotions":          0,
+		"promotions":         0,
+		"dirty":              0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields2, tags2)
 
@@ -67,17 +77,20 @@ func TestDMCacheStats_1(t *testing.T) {
 	}
 
 	fields3 := map[string]interface{}{
-		"metadata_used": 300523520,
-		"metadata_free": 11216781312,
-		"cache_used":    3538944,
-		"cache_free":    1716188741632,
-		"read_hits":     194314240,
-		"read_misses":   92461989888,
-		"write_hits":    21299200,
-		"write_misses":  34397618176,
-		"demotions":     0,
-		"promotions":    1835008,
-		"dirty":         0,
+		"length":             9178759168,
+		"metadata_blocksize": 16,
+		"metadata_used":      73370,
+		"metadata_total":     2811842,
+		"cache_blocksize":    640,
+		"cache_used":         33,
+		"cache_total":        24792130,
+		"read_hits":          2548,
+		"read_misses":        352929,
+		"write_hits":         280,
+		"write_misses":       524728,
+		"demotions":          0,
+		"promotions":         7,
+		"dirty":              0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields3, tags3)
 }
@@ -98,17 +111,20 @@ func TestDMCacheStats_2(t *testing.T) {
 	}
 
 	fields := map[string]interface{}{
-		"metadata_used": 300523520,
-		"metadata_free": 11216781312,
-		"cache_used":    3538944,
-		"cache_free":    1716188741632,
-		"read_hits":     194314240,
-		"read_misses":   92461989888,
-		"write_hits":    21299200,
-		"write_misses":  34397618176,
-		"demotions":     0,
-		"promotions":    1835008,
-		"dirty":         0,
+		"length":             9178759168,
+		"metadata_blocksize": 16,
+		"metadata_used":      73370,
+		"metadata_total":     2811842,
+		"cache_blocksize":    640,
+		"cache_used":         33,
+		"cache_total":        24792130,
+		"read_hits":          2548,
+		"read_misses":        352929,
+		"write_hits":         280,
+		"write_misses":       524728,
+		"demotions":          0,
+		"promotions":         7,
+		"dirty":              0,
 	}
 	acc.AssertContainsTaggedFields(t, "dmcache", fields, tags)
 }

From 9044638fdb2daf5be1f2094836b7d0b0c2d66ef3 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Wed, 5 Apr 2017 11:25:19 +0300
Subject: [PATCH 14/18] updated readme

---
 plugins/inputs/dmcache/README.md | 36 ++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/plugins/inputs/dmcache/README.md b/plugins/inputs/dmcache/README.md
index ae4142e9aa2fa..8e45726860dc2 100644
--- a/plugins/inputs/dmcache/README.md
+++ b/plugins/inputs/dmcache/README.md
@@ -6,10 +6,42 @@ This plugin requires sudo, that is why you should setup and be sure that the tel
 
 `sudo /sbin/dmsetup status --target cache` is the full command that telegraf will run for debugging purposes.
 
-## Configuration
+### Configuration
 
-```
+```toml
 [[inputs.dmcache]]
   ## Whether to report per-device stats or not
   per_device = true
 ```
+
+### Measurements & Fields:
+
+- dmcache
+    - length
+    - target
+    - metadata_blocksize
+    - metadata_used
+    - metadata_total
+    - cache_blocksize
+    - cache_used
+    - cache_total
+    - read_hits
+    - read_misses
+    - write_hits
+    - write_misses
+    - demotions
+    - promotions
+    - dirty
+
+### Tags:
+
+- All measurements have the following tags:
+    - device
+
+### Example Output:
+
+```
+$ ./telegraf --test --config /etc/telegraf/telegraf.conf --input-filter dmcache
+* Plugin: inputs.dmcache, Collection 1
+> dmcache,bu=linux,cls=server,dc=colo,device=vg02-splunk_data_lv,env=production,host=hostname,sr=splunk_indexer,trd=false cache_free=0i,cache_used=1099511627776i,demotions=3265223720960i,dirty=0i,metadata_free=1060880384i,metadata_used=12861440i,promotions=3265223720960i,read_hits=995134034411520i,read_misses=916807089127424i,write_hits=195107267543040i,write_misses=563725346013184i 1491362011000000000
+```
\ No newline at end of file

From 6ab3f047a7905a224cb341314e9fc8f08f8b1442 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Wed, 5 Apr 2017 12:08:41 +0300
Subject: [PATCH 15/18] refactored map to struct

---
 plugins/inputs/dmcache/dmcache.go       |  18 ----
 plugins/inputs/dmcache/dmcache_linux.go | 135 ++++++++++++++++--------
 plugins/inputs/dmcache/dmcache_test.go  |   4 -
 3 files changed, 92 insertions(+), 65 deletions(-)

diff --git a/plugins/inputs/dmcache/dmcache.go b/plugins/inputs/dmcache/dmcache.go
index b933cc098b10a..25a398194edf8 100644
--- a/plugins/inputs/dmcache/dmcache.go
+++ b/plugins/inputs/dmcache/dmcache.go
@@ -1,9 +1,6 @@
 package dmcache
 
 import (
-	"os/exec"
-	"strings"
-
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
@@ -26,21 +23,6 @@ func (c *DMCache) Description() string {
 	return "Provide a native collection for dmsetup based statistics for dm-cache"
 }
 
-func dmSetupStatus() ([]string, error) {
-	out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
-	if err != nil {
-		return nil, err
-	}
-	if string(out) == "No devices found\n" {
-		return []string{}, nil
-	}
-
-	outString := strings.TrimRight(string(out), "\n")
-	status := strings.Split(outString, "\n")
-
-	return status, nil
-}
-
 func init() {
 	inputs.Add("dmcache", func() telegraf.Input {
 		return &DMCache{
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index 84cece5684ab7..8c698834b384f 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -3,6 +3,7 @@
 package dmcache
 
 import (
+	"os/exec"
 	"strconv"
 	"strings"
 
@@ -13,6 +14,25 @@ import (
 
 const metricName = "dmcache"
 
+type cacheStatus struct {
+	device            string
+	length            int
+	target            string
+	metadataBlocksize int
+	metadataUsed      int
+	metadataTotal     int
+	cacheBlocksize    int
+	cacheUsed         int
+	cacheTotal        int
+	readHits          int
+	readMisses        int
+	writeHits         int
+	writeMisses       int
+	demotions         int
+	promotions        int
+	dirty             int
+}
+
 func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	outputLines, err := c.getCurrentStatus()
 	if err != nil {
@@ -22,13 +42,29 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	total := make(map[string]interface{})
 
 	for _, s := range outputLines {
-		fields, err := parseDMSetupStatus(s)
+		status, err := parseDMSetupStatus(s)
 		if err != nil {
 			return err
 		}
 
+		fields := make(map[string]interface{})
+		fields["length"] = status.length
+		fields["metadata_blocksize"] = status.metadataBlocksize
+		fields["metadata_used"] = status.metadataUsed
+		fields["metadata_total"] = status.metadataTotal
+		fields["cache_blocksize"] = status.cacheBlocksize
+		fields["cache_used"] = status.cacheUsed
+		fields["cache_total"] = status.cacheTotal
+		fields["read_hits"] = status.readHits
+		fields["read_misses"] = status.readMisses
+		fields["write_hits"] = status.writeHits
+		fields["write_misses"] = status.writeMisses
+		fields["demotions"] = status.demotions
+		fields["promotions"] = status.promotions
+		fields["dirty"] = status.dirty
+
 		if c.PerDevice {
-			tags := map[string]string{"device": fields["device"].(string)}
+			tags := map[string]string{"device": status.device}
 			acc.AddFields(metricName, fields, tags)
 		}
 		aggregateStats(total, fields)
@@ -39,80 +75,80 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
-func parseDMSetupStatus(line string) (map[string]interface{}, error) {
+func parseDMSetupStatus(line string) (cacheStatus, error) {
 	var err error
 	parseError := errors.New("Output from dmsetup could not be parsed")
-	status := make(map[string]interface{})
+	status := cacheStatus{}
 	values := strings.Fields(line)
 	if len(values) < 15 {
-		return nil, parseError
+		return cacheStatus{}, parseError
 	}
 
-	status["device"] = strings.TrimRight(values[0], ":")
-	status["length"], err = strconv.Atoi(values[2])
+	status.device = strings.TrimRight(values[0], ":")
+	status.length, err = strconv.Atoi(values[2])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["target"] = values[3]
-	status["metadata_blocksize"], err = strconv.Atoi(values[4])
+	status.target = values[3]
+	status.metadataBlocksize, err = strconv.Atoi(values[4])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
 	metadata := strings.Split(values[5], "/")
 	if len(metadata) != 2 {
-		return nil, parseError
+		return cacheStatus{}, parseError
 	}
-	status["metadata_used"], err = strconv.Atoi(metadata[0])
+	status.metadataUsed, err = strconv.Atoi(metadata[0])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["metadata_total"], err = strconv.Atoi(metadata[1])
+	status.metadataTotal, err = strconv.Atoi(metadata[1])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["cache_blocksize"], err = strconv.Atoi(values[6])
+	status.cacheBlocksize, err = strconv.Atoi(values[6])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
 	cache := strings.Split(values[7], "/")
 	if len(cache) != 2 {
-		return nil, parseError
+		return cacheStatus{}, parseError
 	}
-	status["cache_used"], err = strconv.Atoi(cache[0])
+	status.cacheUsed, err = strconv.Atoi(cache[0])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["cache_total"], err = strconv.Atoi(cache[1])
+	status.cacheTotal, err = strconv.Atoi(cache[1])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["read_hits"], err = strconv.Atoi(values[8])
+	status.readHits, err = strconv.Atoi(values[8])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["read_misses"], err = strconv.Atoi(values[9])
+	status.readMisses, err = strconv.Atoi(values[9])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["write_hits"], err = strconv.Atoi(values[10])
+	status.writeHits, err = strconv.Atoi(values[10])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["write_misses"], err = strconv.Atoi(values[11])
+	status.writeMisses, err = strconv.Atoi(values[11])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["demotions"], err = strconv.Atoi(values[12])
+	status.demotions, err = strconv.Atoi(values[12])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["promotions"], err = strconv.Atoi(values[13])
+	status.promotions, err = strconv.Atoi(values[13])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
-	status["dirty"], err = strconv.Atoi(values[14])
+	status.dirty, err = strconv.Atoi(values[14])
 	if err != nil {
-		return nil, err
+		return cacheStatus{}, err
 	}
 
 	return status, nil
@@ -120,12 +156,25 @@ func parseDMSetupStatus(line string) (map[string]interface{}, error) {
 
 func aggregateStats(total, fields map[string]interface{}) {
 	for key, value := range fields {
-		if _, ok := value.(int); ok {
-			if _, ok := total[key]; ok {
-				total[key] = total[key].(int) + value.(int)
-			} else {
-				total[key] = value.(int)
-			}
+		if _, ok := total[key]; ok {
+			total[key] = total[key].(int) + value.(int)
+		} else {
+			total[key] = value.(int)
 		}
 	}
 }
+
+func dmSetupStatus() ([]string, error) {
+	out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
+	if err != nil {
+		return nil, err
+	}
+	if string(out) == "No devices found\n" {
+		return []string{}, nil
+	}
+
+	outString := strings.TrimRight(string(out), "\n")
+	status := strings.Split(outString, "\n")
+
+	return status, nil
+}
diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index 2c317f9da16b7..e30b91e2ee6f4 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -30,9 +30,7 @@ func TestDMCacheStats_1(t *testing.T) {
 		"device": "cs-1",
 	}
 	fields1 := map[string]interface{}{
-		"device":             "cs-1",
 		"length":             4883791872,
-		"target":             "cache",
 		"metadata_blocksize": 8,
 		"metadata_used":      1018,
 		"metadata_total":     1501122,
@@ -53,9 +51,7 @@ func TestDMCacheStats_1(t *testing.T) {
 		"device": "cs-2",
 	}
 	fields2 := map[string]interface{}{
-		"device":             "cs-2",
 		"length":             4294967296,
-		"target":             "cache",
 		"metadata_blocksize": 8,
 		"metadata_used":      72352,
 		"metadata_total":     1310720,

From 95e01e058e8ed872e99ee5567dcbf207690d0a0e Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Thu, 6 Apr 2017 15:54:26 +0300
Subject: [PATCH 16/18] refactoring: switching to fields at the last moment

---
 plugins/inputs/dmcache/README.md        |  4 +-
 plugins/inputs/dmcache/dmcache_linux.go | 66 ++++++++++++++-----------
 2 files changed, 40 insertions(+), 30 deletions(-)

diff --git a/plugins/inputs/dmcache/README.md b/plugins/inputs/dmcache/README.md
index 8e45726860dc2..536d3f518bcaa 100644
--- a/plugins/inputs/dmcache/README.md
+++ b/plugins/inputs/dmcache/README.md
@@ -43,5 +43,5 @@ This plugin requires sudo, that is why you should setup and be sure that the tel
 ```
 $ ./telegraf --test --config /etc/telegraf/telegraf.conf --input-filter dmcache
 * Plugin: inputs.dmcache, Collection 1
-> dmcache,bu=linux,cls=server,dc=colo,device=vg02-splunk_data_lv,env=production,host=hostname,sr=splunk_indexer,trd=false cache_free=0i,cache_used=1099511627776i,demotions=3265223720960i,dirty=0i,metadata_free=1060880384i,metadata_used=12861440i,promotions=3265223720960i,read_hits=995134034411520i,read_misses=916807089127424i,write_hits=195107267543040i,write_misses=563725346013184i 1491362011000000000
-```
\ No newline at end of file
+> dmcache,device=example cache_blocksize=0i,read_hits=995134034411520i,read_misses=916807089127424i,write_hits=195107267543040i,metadata_used=12861440i,write_misses=563725346013184i,promotions=3265223720960i,dirty=0i,metadata_blocksize=0i,cache_used=1099511627776ii,cache_total=0i,length=0i,metadata_total=1073741824i,demotions=3265223720960i 1491482035000000000
+```
diff --git a/plugins/inputs/dmcache/dmcache_linux.go b/plugins/inputs/dmcache/dmcache_linux.go
index 8c698834b384f..7ac1c96cae0f1 100644
--- a/plugins/inputs/dmcache/dmcache_linux.go
+++ b/plugins/inputs/dmcache/dmcache_linux.go
@@ -39,7 +39,7 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 		return err
 	}
 
-	total := make(map[string]interface{})
+	totalStatus := cacheStatus{}
 
 	for _, s := range outputLines {
 		status, err := parseDMSetupStatus(s)
@@ -47,30 +47,14 @@ func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 			return err
 		}
 
-		fields := make(map[string]interface{})
-		fields["length"] = status.length
-		fields["metadata_blocksize"] = status.metadataBlocksize
-		fields["metadata_used"] = status.metadataUsed
-		fields["metadata_total"] = status.metadataTotal
-		fields["cache_blocksize"] = status.cacheBlocksize
-		fields["cache_used"] = status.cacheUsed
-		fields["cache_total"] = status.cacheTotal
-		fields["read_hits"] = status.readHits
-		fields["read_misses"] = status.readMisses
-		fields["write_hits"] = status.writeHits
-		fields["write_misses"] = status.writeMisses
-		fields["demotions"] = status.demotions
-		fields["promotions"] = status.promotions
-		fields["dirty"] = status.dirty
-
 		if c.PerDevice {
 			tags := map[string]string{"device": status.device}
-			acc.AddFields(metricName, fields, tags)
+			acc.AddFields(metricName, toFields(status), tags)
 		}
-		aggregateStats(total, fields)
+		aggregateStats(&totalStatus, status)
 	}
 
-	acc.AddFields(metricName, total, map[string]string{"device": "all"})
+	acc.AddFields(metricName, toFields(totalStatus), map[string]string{"device": "all"})
 
 	return nil
 }
@@ -154,14 +138,40 @@ func parseDMSetupStatus(line string) (cacheStatus, error) {
 	return status, nil
 }
 
-func aggregateStats(total, fields map[string]interface{}) {
-	for key, value := range fields {
-		if _, ok := total[key]; ok {
-			total[key] = total[key].(int) + value.(int)
-		} else {
-			total[key] = value.(int)
-		}
-	}
+func aggregateStats(totalStatus *cacheStatus, status cacheStatus) {
+	totalStatus.length += status.length
+	totalStatus.metadataBlocksize += status.metadataBlocksize
+	totalStatus.metadataUsed += status.metadataUsed
+	totalStatus.metadataTotal += status.metadataTotal
+	totalStatus.cacheBlocksize += status.cacheBlocksize
+	totalStatus.cacheUsed += status.cacheUsed
+	totalStatus.cacheTotal += status.cacheTotal
+	totalStatus.readHits += status.readHits
+	totalStatus.readMisses += status.readMisses
+	totalStatus.writeHits += status.writeHits
+	totalStatus.writeMisses += status.writeMisses
+	totalStatus.demotions += status.demotions
+	totalStatus.promotions += status.promotions
+	totalStatus.dirty += status.dirty
+}
+
+func toFields(status cacheStatus) map[string]interface{} {
+	fields := make(map[string]interface{})
+	fields["length"] = status.length
+	fields["metadata_blocksize"] = status.metadataBlocksize
+	fields["metadata_used"] = status.metadataUsed
+	fields["metadata_total"] = status.metadataTotal
+	fields["cache_blocksize"] = status.cacheBlocksize
+	fields["cache_used"] = status.cacheUsed
+	fields["cache_total"] = status.cacheTotal
+	fields["read_hits"] = status.readHits
+	fields["read_misses"] = status.readMisses
+	fields["write_hits"] = status.writeHits
+	fields["write_misses"] = status.writeMisses
+	fields["demotions"] = status.demotions
+	fields["promotions"] = status.promotions
+	fields["dirty"] = status.dirty
+	return fields
 }
 
 func dmSetupStatus() ([]string, error) {

From 798175764c822f1003133f377dc7ca96f1d9fc98 Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Fri, 7 Apr 2017 11:49:27 +0300
Subject: [PATCH 17/18] tests refactoring

---
 plugins/inputs/dmcache/dmcache_test.go | 107 ++++++++++++-------------
 1 file changed, 50 insertions(+), 57 deletions(-)

diff --git a/plugins/inputs/dmcache/dmcache_test.go b/plugins/inputs/dmcache/dmcache_test.go
index e30b91e2ee6f4..c5989c413d9c0 100644
--- a/plugins/inputs/dmcache/dmcache_test.go
+++ b/plugins/inputs/dmcache/dmcache_test.go
@@ -8,22 +8,25 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func output2Devices() ([]string, error) {
-	return []string{
+var (
+	measurement              = "dmcache"
+	badFormatOutput          = []string{"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 "}
+	good2DevicesFormatOutput = []string{
 		"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 15 46 0 7 0 1 writeback 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
 		"cs-2: 0 4294967296 cache 8 72352/1310720 128 26/24327168 2409 286 265 524682 0 0 0 1 writethrough 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
-	}, nil
-}
-
-var dmc1 = &DMCache{
-	PerDevice:        true,
-	getCurrentStatus: output2Devices,
-}
+	}
+)
 
-func TestDMCacheStats_1(t *testing.T) {
+func TestPerDeviceGoodOutput(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: true,
+		getCurrentStatus: func() ([]string, error) {
+			return good2DevicesFormatOutput, nil
+		},
+	}
 
-	err := dmc1.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.NoError(t, err)
 
 	tags1 := map[string]string{
@@ -45,7 +48,7 @@ func TestDMCacheStats_1(t *testing.T) {
 		"promotions":         7,
 		"dirty":              0,
 	}
-	acc.AssertContainsTaggedFields(t, "dmcache", fields1, tags1)
+	acc.AssertContainsTaggedFields(t, measurement, fields1, tags1)
 
 	tags2 := map[string]string{
 		"device": "cs-2",
@@ -66,7 +69,7 @@ func TestDMCacheStats_1(t *testing.T) {
 		"promotions":         0,
 		"dirty":              0,
 	}
-	acc.AssertContainsTaggedFields(t, "dmcache", fields2, tags2)
+	acc.AssertContainsTaggedFields(t, measurement, fields2, tags2)
 
 	tags3 := map[string]string{
 		"device": "all",
@@ -88,18 +91,19 @@ func TestDMCacheStats_1(t *testing.T) {
 		"promotions":         7,
 		"dirty":              0,
 	}
-	acc.AssertContainsTaggedFields(t, "dmcache", fields3, tags3)
+	acc.AssertContainsTaggedFields(t, measurement, fields3, tags3)
 }
 
-var dmc2 = &DMCache{
-	PerDevice:        false,
-	getCurrentStatus: output2Devices,
-}
-
-func TestDMCacheStats_2(t *testing.T) {
+func TestNotPerDeviceGoodOutput(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: false,
+		getCurrentStatus: func() ([]string, error) {
+			return good2DevicesFormatOutput, nil
+		},
+	}
 
-	err := dmc2.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.NoError(t, err)
 
 	tags := map[string]string{
@@ -122,55 +126,44 @@ func TestDMCacheStats_2(t *testing.T) {
 		"promotions":         7,
 		"dirty":              0,
 	}
-	acc.AssertContainsTaggedFields(t, "dmcache", fields, tags)
-}
-
-func outputNoDevices() ([]string, error) {
-	return []string{}, nil
-}
-
-var dmc3 = &DMCache{
-	PerDevice:        true,
-	getCurrentStatus: outputNoDevices,
+	acc.AssertContainsTaggedFields(t, measurement, fields, tags)
 }
 
-func TestDMCacheStats_3(t *testing.T) {
+func TestNoDevicesOutput(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: true,
+		getCurrentStatus: func() ([]string, error) {
+			return []string{}, nil
+		},
+	}
 
-	err := dmc3.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.NoError(t, err)
 }
 
-func noDMSetup() ([]string, error) {
-	return []string{}, errors.New("dmsetup doesn't exist")
-}
-
-var dmc4 = &DMCache{
-	PerDevice:        true,
-	getCurrentStatus: noDMSetup,
-}
-
-func TestDMCacheStats_4(t *testing.T) {
+func TestErrorDuringGettingStatus(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: true,
+		getCurrentStatus: func() ([]string, error) {
+			return nil, errors.New("dmsetup doesn't exist")
+		},
+	}
 
-	err := dmc4.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.Error(t, err)
 }
 
-func badFormat() ([]string, error) {
-	return []string{
-		"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 ",
-	}, nil
-}
-
-var dmc5 = &DMCache{
-	PerDevice:        true,
-	getCurrentStatus: badFormat,
-}
-
-func TestDMCacheStats_5(t *testing.T) {
+func TestBadFormatOfStatus(t *testing.T) {
 	var acc testutil.Accumulator
+	var plugin = &DMCache{
+		PerDevice: true,
+		getCurrentStatus: func() ([]string, error) {
+			return badFormatOutput, nil
+		},
+	}
 
-	err := dmc5.Gather(&acc)
+	err := plugin.Gather(&acc)
 	require.Error(t, err)
 }

From bc220fbb9b6ec502dd03fd49561d6cb6261096bd Mon Sep 17 00:00:00 2001
From: Vladimir Sagan <vlasad@gmail.com>
Date: Sat, 8 Apr 2017 00:18:04 +0300
Subject: [PATCH 18/18] added stub dmSetupStatus func for not linux build

---
 plugins/inputs/dmcache/dmcache_notlinux.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/plugins/inputs/dmcache/dmcache_notlinux.go b/plugins/inputs/dmcache/dmcache_notlinux.go
index 478c2f163e4dc..ee1065638cab7 100644
--- a/plugins/inputs/dmcache/dmcache_notlinux.go
+++ b/plugins/inputs/dmcache/dmcache_notlinux.go
@@ -9,3 +9,7 @@ import (
 func (c *DMCache) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
+
+func dmSetupStatus() ([]string, error) {
+	return []string{}, nil
+}