Assign object name from counter path when the instance name is not de…

…fined (#11878)

* Assign object name from counter path when the instance name is not defined

Fixes #6528

* Adressed review comments

* Fix changelog entry

CHANGELOG.next.asciidoc

@@ -165,6 +165,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Allow module configurations to have variants {pull}9118[9118]
 - Add `timeseries.instance` field calculation. {pull}10293[10293]
 - Added new disk states and raid level to the system/raid metricset. {pull}11613[11613]
+- Add check on object name in the counter path if the instance name is missing {issue}6528[6528] {pull}11878[11878]
 
 *Packetbeat*
 

metricbeat/module/windows/perfmon/pdh_integration_windows_test.go

@@ -24,6 +24,8 @@ import (
 	"time"
 	"unsafe"
 
+	"github.com/elastic/beats/libbeat/common"
+
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 
@@ -72,6 +74,36 @@ func TestData(t *testing.T) {
 	mbtest.WriteEventToDataJSON(t, beatEvent, "")
 }
 
+func TestCounterWithNoInstanceName(t *testing.T) {
+	config := map[string]interface{}{
+		"module":     "windows",
+		"metricsets": []string{"perfmon"},
+		"perfmon.counters": []map[string]string{
+			{
+				"instance_label":    "processor.name",
+				"measurement_label": "processor.time.total.pct",
+				"query":             `\UDPv4\Datagrams Sent/sec`,
+			},
+		},
+	}
+
+	ms := mbtest.NewReportingMetricSetV2(t, config)
+	mbtest.ReportingFetchV2(ms)
+	time.Sleep(60 * time.Millisecond)
+
+	events, errs := mbtest.ReportingFetchV2(ms)
+	if len(errs) > 0 {
+		t.Fatal(errs)
+	}
+	if len(events) == 0 {
+		t.Fatal("no events received")
+	}
+	process := events[0].MetricSetFields["processor"].(common.MapStr)
+	// Check values
+	assert.EqualValues(t, "UDPv4", process["name"])
+
+}
+
 func TestQuery(t *testing.T) {
 	q, err := NewQuery("")
 	if err != nil {

metricbeat/module/windows/perfmon/pdh_windows.go

@@ -52,6 +52,7 @@ var (
 	sizeofPdhCounterValueItem = (int)(unsafe.Sizeof(pdhCounterValueItem{}))
 	wildcardRegexp            = regexp.MustCompile(`.*\(\*\).*`)
 	instanceNameRegexp        = regexp.MustCompile(`.*\((.*)\).*`)
+	objectNameRegexp          = regexp.MustCompile(`\\([^\\]+)\\`)
 )
 
 type PdhQueryHandle uintptr
@@ -247,13 +248,11 @@ func (q *Query) AddCounter(counterPath string, format Format, instanceName strin
 
 	// Extract the instance name from the counterPath for non-wildcard paths.
 	if !wildcard && instanceName == "" {
-		matches := instanceNameRegexp.FindStringSubmatch(counterPath)
-		if len(matches) != 2 {
-			return errors.New("query doesn't contain an instance name. In this case you have to define 'instance_name'")
+		instanceName, err = matchInstanceName(counterPath)
+		if err != nil {
+			return err
 		}
-		instanceName = matches[1]
 	}
-
 	q.counters[counterPath] = &Counter{
 		handle:       h,
 		instanceName: instanceName,
@@ -268,6 +267,18 @@ func (q *Query) AddCounter(counterPath string, format Format, instanceName strin
 	return nil
 }
 
+// matchInstanceName will check first for instance and then for any objects names
+func matchInstanceName(counterPath string) (string, error) {
+	matches := instanceNameRegexp.FindStringSubmatch(counterPath)
+	if len(matches) != 2 {
+		matches = objectNameRegexp.FindStringSubmatch(counterPath)
+	}
+	if len(matches) == 2 {
+		return matches[1], nil
+	}
+	return "", errors.New("query doesn't contain an instance name. In this case you have to define 'instance_name'")
+}
+
 func (q *Query) Execute() error {
 	return PdhCollectQueryData(q.handle)
 }