Fix memory leak by updating go-ole and adding wbem initialization (#82)

exporter.go

@@ -13,6 +13,7 @@ import (
 
 	"golang.org/x/sys/windows/svc"
 
+	"github.com/StackExchange/wmi"
 	"github.com/martinlindhe/wmi_exporter/collector"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -130,6 +131,18 @@ func init() {
 	prometheus.MustRegister(version.NewCollector("wmi_exporter"))
 }
 
+func initWbem() {
+	// This initialization prevents a memory leak on WMF 5+. See
+	// https://github.com/martinlindhe/wmi_exporter/issues/77 and linked issues
+	// for details.
+	log.Debugf("Initializing SWbemServices")
+	s, err := wmi.InitializeSWbemServices(wmi.DefaultClient)
+	if err != nil {
+		log.Fatal(err)
+	}
+	wmi.DefaultClient.SWbemServicesClient = s
+}
+
 func main() {
 	var (
 		showVersion       = flag.Bool("version", false, "Print version information.")
@@ -158,6 +171,8 @@ func main() {
 		return
 	}
 
+	initWbem()
+
 	isInteractive, err := svc.IsAnInteractiveSession()
 	if err != nil {
 		log.Fatal(err)

vendor/vendor.json

@@ -9,10 +9,10 @@
 			"revisionTime": "2016-08-29T20:23:21Z"
 		},
 		{
-			"checksumSHA1": "9NR0rrcAT5J76C5xMS4AVksS9o0=",
+			"checksumSHA1": "qtjd74+bErubh+qyv3s+lWmn9wc=",
 			"path": "github.com/StackExchange/wmi",
-			"revision": "e54cbda6595d7293a7a468ccf9525f6bc8887f99",
-			"revisionTime": "2016-08-11T21:45:55Z"
+			"revision": "ea383cf3ba6ec950874b8486cd72356d007c768f",
+			"revisionTime": "2017-04-10T19:29:09Z"
 		},
 		{
 			"checksumSHA1": "spyv5/YFBjYyZLZa1U2LBfDR8PM=",
@@ -21,10 +21,10 @@
 			"revisionTime": "2016-08-04T10:47:26Z"
 		},
 		{
-			"checksumSHA1": "wDZdTaY9JiqqqnF4c3pHP71nWmk=",
+			"checksumSHA1": "oyULO1B/l2OLy2xereo+2w3hYk4=",
 			"path": "github.com/go-ole/go-ole",
-			"revision": "7dfdcf409020452e29b4babcbb22f984d2aa308a",
-			"revisionTime": "2016-07-29T03:38:29Z"
+			"revision": "02d3668a0cf01f58411cc85cd37c174c257ec7c2",
+			"revisionTime": "2017-06-01T13:56:11Z"
 		},
 		{
 			"checksumSHA1": "qLYVTQDhgrVIeZ2KI9eZV51mmug=",