win_perf_counters: New option "Expand" expands wildcards in counter definitions.

plugins/inputs/win_perf_counters/README.md

@@ -121,6 +121,15 @@ It is a simple bool, if it is not set to true or included this is treaded as fal
 If this is set to true, the plugin will abort and end prematurely
 if any of the combinations of ObjectName/Instances/Counters are invalid.
 
+#### Expand
+*Optional*
+
+This key is optional, it is a simple bool.
+If it is not set to true or included it is treated as false.
+When the option is set to true Telegraf will expand wildcards "*"
+used in defintions of ObjectName/Instance/Counter.
+Read more about wildcards in https://msdn.microsoft.com/en-us/library/windows/desktop/aa372605(v=vs.85).aspx
+
 ## Examples
 
 ### Generic Queries

plugins/inputs/win_perf_counters/pdh.go

@@ -208,6 +208,7 @@ var (
 	pdh_GetFormattedCounterArrayW *syscall.Proc
 	pdh_OpenQuery                 *syscall.Proc
 	pdh_ValidatePathW             *syscall.Proc
+	pdh_ExpandWildCardPathW       *syscall.Proc
 )
 
 func init() {
@@ -223,6 +224,7 @@ func init() {
 	pdh_GetFormattedCounterArrayW = libpdhDll.MustFindProc("PdhGetFormattedCounterArrayW")
 	pdh_OpenQuery = libpdhDll.MustFindProc("PdhOpenQuery")
 	pdh_ValidatePathW = libpdhDll.MustFindProc("PdhValidatePathW")
+	pdh_ExpandWildCardPathW = libpdhDll.MustFindProc("PdhExpandWildCardPathW")
 }
 
 // Adds the specified counter to the query. This is the internationalized version. Preferably, use the
@@ -402,6 +404,19 @@ func PdhOpenQuery(szDataSource uintptr, dwUserData uintptr, phQuery *PDH_HQUERY)
 	return uint32(ret)
 }
 
+func PdhExpandWildCardPath(szWildCardPath string, mszExpandedPathList *uint16, pcchPathListLength *uint32) uint32 {
+	ptxt, _ := syscall.UTF16PtrFromString(szWildCardPath)
+	flags := uint32(0) // expand instances and counters
+	ret, _, _ := pdh_ExpandWildCardPathW.Call(
+		uintptr(unsafe.Pointer(nil)), // search counters on local computer
+		uintptr(unsafe.Pointer(ptxt)),
+		uintptr(unsafe.Pointer(mszExpandedPathList)),
+		uintptr(unsafe.Pointer(pcchPathListLength)),
+		uintptr(unsafe.Pointer(&flags)))
+
+	return uint32(ret)
+}
+
 // Validates a path. Will return ERROR_SUCCESS when ok, or PDH_CSTATUS_BAD_COUNTERNAME when the path is
 // erroneous.
 func PdhValidatePath(path string) uint32 {
@@ -417,3 +432,16 @@ func UTF16PtrToString(s *uint16) string {
 	}
 	return syscall.UTF16ToString((*[1 << 29]uint16)(unsafe.Pointer(s))[0:])
 }
+
+func UTF16ToStringArray(buf []uint16) []string {
+	var strings []string
+	nextLineStart := 0
+	stringLine := UTF16PtrToString(&buf[0])
+	for stringLine != "" {
+		strings = append(strings, stringLine)
+		nextLineStart += len(stringLine) + 1
+		remainingBuf := buf[nextLineStart:]
+		stringLine = UTF16PtrToString(&remainingBuf[0])
+	}
+	return strings
+}

plugins/inputs/win_perf_counters/win_perf_counters.go

@@ -12,7 +12,7 @@ import (
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
 
-var sampleConfig string = `
+var sampleConfig = `
   ## By default this plugin returns basic CPU and Disk statistics.
   ## See the README file for more examples.
   ## Uncomment examples below or write your own as you see fit. If the system
@@ -87,6 +87,7 @@ type perfobject struct {
 	WarnOnMissing bool
 	FailOnMissing bool
 	IncludeTotal  bool
+	Expand        bool
 }
 
 // Parsed configuration ends up here after it has been validated for valid
@@ -109,8 +110,14 @@ type item struct {
 var sanitizedChars = strings.NewReplacer("/sec", "_persec", "/Sec", "_persec",
 	" ", "_", "%", "Percent", `\`, "")
 
-func (m *Win_PerfCounters) AddItem(metrics *itemList, query string, objectName string, counter string, instance string,
-	measurement string, include_total bool) error {
+func (m *Win_PerfCounters) AddItem(
+	metrics *itemList,
+	query string,
+	objectName string,
+	counter string,
+	instance string,
+	measurement string,
+	includeTotal bool) error {
 
 	var handle PDH_HQUERY
 	var counterHandle PDH_HCOUNTER
@@ -129,7 +136,7 @@ func (m *Win_PerfCounters) AddItem(metrics *itemList, query string, objectName s
 	}
 
 	temp := &item{query, objectName, counter, instance, measurement,
-		include_total, handle, counterHandle}
+		includeTotal, handle, counterHandle}
 	index := len(gItemList)
 	gItemList[index] = temp
 
@@ -148,34 +155,69 @@ func (m *Win_PerfCounters) SampleConfig() string {
 	return sampleConfig
 }
 
-func (m *Win_PerfCounters) ParseConfig(metrics *itemList) error {
-	var query string
+func expandCounterQuery(query string) ([]string, error) {
+	var bufSize uint32
+	var buf []uint16
+	ret := PdhExpandWildCardPath(query, nil, &bufSize)
+	for ret == PDH_MORE_DATA {
+		buf = make([]uint16, bufSize)
+		ret = PdhExpandWildCardPath(query, &buf[0], &bufSize)
+	}
+	if ret == ERROR_SUCCESS {
+		return UTF16ToStringArray(buf), nil
+	}
+	return nil, fmt.Errorf("Failed to expand query: '%s', err(%d)", query, ret)
+}
+
+func formatCounterQuery(objectname string, instance string, counter string) string {
+	if instance == "------" {
+		return "\\" + objectname + "\\" + counter
+	}
+	return "\\" + objectname + "(" + instance + ")\\" + counter
+}
+
+func (m *Win_PerfCounters) ProcessQueryStatus(query string, err error, perfObject perfobject) {
+	if err == nil {
+		if m.PrintValid {
+			fmt.Printf("Valid: %s\n", query)
+		}
+	} else {
+		if perfObject.FailOnMissing || perfObject.WarnOnMissing {
+			fmt.Printf("Invalid query: %s\n", query)
+		}
+	}
+}
+
+func expandQuery(query string, expand bool) ([]string, error) {
+	if expand {
+		return expandCounterQuery(query)
+	}
+	return []string{query}, nil
+}
 
+func (m *Win_PerfCounters) ParseConfig(metrics *itemList) error {
 	configParsed = true
 
 	if len(m.Object) > 0 {
 		for _, PerfObject := range m.Object {
 			for _, counter := range PerfObject.Counters {
 				for _, instance := range PerfObject.Instances {
 					objectname := PerfObject.ObjectName
+					query := formatCounterQuery(objectname, instance, counter)
+					expandedQueries, err := expandQuery(query, PerfObject.Expand)
 
-					if instance == "------" {
-						query = "\\" + objectname + "\\" + counter
-					} else {
-						query = "\\" + objectname + "(" + instance + ")\\" + counter
+					if err != nil {
+						m.ProcessQueryStatus(query, err, PerfObject)
+						if PerfObject.FailOnMissing {
+							return err
+						}
+						continue
 					}
 
-					err := m.AddItem(metrics, query, objectname, counter, instance,
-						PerfObject.Measurement, PerfObject.IncludeTotal)
-
-					if err == nil {
-						if m.PrintValid {
-							fmt.Printf("Valid: %s\n", query)
-						}
-					} else {
-						if PerfObject.FailOnMissing || PerfObject.WarnOnMissing {
-							fmt.Printf("Invalid query: %s\n", query)
-						}
+					for _, expandedQuery := range expandedQueries {
+						err = m.AddItem(metrics, expandedQuery, objectname, counter, instance,
+							PerfObject.Measurement, PerfObject.IncludeTotal)
+						m.ProcessQueryStatus(expandedQuery, err, PerfObject)
 						if PerfObject.FailOnMissing {
 							return err
 						}
@@ -233,8 +275,8 @@ func (m *Win_PerfCounters) Gather(acc telegraf.Accumulator) error {
 
 	var bufSize uint32
 	var bufCount uint32
-	var size uint32 = uint32(unsafe.Sizeof(PDH_FMT_COUNTERVALUE_ITEM_DOUBLE{}))
 	var emptyBuf [1]PDH_FMT_COUNTERVALUE_ITEM_DOUBLE // need at least 1 addressable null ptr.
+	size := uint32(unsafe.Sizeof(PDH_FMT_COUNTERVALUE_ITEM_DOUBLE{}))
 
 	// For iterate over the known metrics and get the samples.
 	for _, metric := range gItemList {
@@ -252,7 +294,7 @@ func (m *Win_PerfCounters) Gather(acc telegraf.Accumulator) error {
 					&bufSize, &bufCount, &filledBuf[0])
 				for i := 0; i < int(bufCount); i++ {
 					c := filledBuf[i]
-					var s string = UTF16PtrToString(c.SzName)
+					s := UTF16PtrToString(c.SzName)
 
 					var add bool