metrics: export number of open-files by mode

Provides two new metrics: number of total open-file in RO/RW modes. Uses
the detailed SMB information provided by 'open_files' section per file.

Signed-off-by: Shachar Sharon <[email protected]>

Author: synarete

internal/metrics/collectors.go

@@ -88,12 +88,14 @@ func (col *smbActivityCollector) Collect(ch chan<- prometheus.Metric) {
 	totalTreeCons := 0
 	totalConnectedUsers := 0
 	totalOpenFiles := 0
+	totalOpenFilesAccessRW := 0
 	smbInfo, err := NewUpdatedSMBInfo()
 	if err == nil {
 		totalSessions = smbInfo.TotalSessions()
 		totalTreeCons = smbInfo.TotalTreeCons()
 		totalConnectedUsers = smbInfo.TotalConnectedUsers()
 		totalOpenFiles = smbInfo.TotalOpenFiles()
+		totalOpenFilesAccessRW = smbInfo.TotalOpenFilesAccessRW()
 	}
 	ch <- prometheus.MustNewConstMetric(col.dsc[0],
 		prometheus.GaugeValue, float64(totalSessions))
@@ -106,6 +108,9 @@ func (col *smbActivityCollector) Collect(ch chan<- prometheus.Metric) {
 
 	ch <- prometheus.MustNewConstMetric(col.dsc[3],
 		prometheus.GaugeValue, float64(totalOpenFiles))
+
+	ch <- prometheus.MustNewConstMetric(col.dsc[4],
+		prometheus.GaugeValue, float64(totalOpenFilesAccessRW))
 }
 
 func (sme *smbMetricsExporter) newSMBActivityCollector() prometheus.Collector {
@@ -131,6 +136,11 @@ func (sme *smbMetricsExporter) newSMBActivityCollector() prometheus.Collector {
 			collectorName("openfiles", "total"),
 			"Number of currently open files",
 			[]string{}, nil),
+
+		prometheus.NewDesc(
+			collectorName("openfiles", "access_rw"),
+			"Number of open files with read-write access mode",
+			[]string{}, nil),
 	}
 	return col
 }

internal/metrics/smbinfo.go

@@ -2,6 +2,8 @@
 
 package metrics
 
+import "strings"
+
 // SMBInfo provides a bridge layer between raw smbstatus info and exported
 // metric counters. It also implements the more complex logic which requires in
 // memory re-mapping of the low-level information (e.g., stats by machine/user).
@@ -40,6 +42,18 @@ func (smbinfo *SMBInfo) TotalOpenFiles() int {
 	return len(smbinfo.smbstat.OpenFiles)
 }
 
+func (smbinfo *SMBInfo) TotalOpenFilesAccessRW() int {
+	total := 0
+	for _, openf := range smbinfo.smbstat.OpenFiles {
+		for _, opens := range openf.Opens {
+			if strings.Contains(opens.AccessMask.Text, "RW") {
+				total++
+			}
+		}
+	}
+	return total
+}
+
 func (smbinfo *SMBInfo) TotalConnectedUsers() int {
 	users := map[string]bool{}
 	for _, session := range smbinfo.smbstat.Sessions {