collector/mountstats: add NFS mountpoint info metric

collector/fixtures/e2e-64k-page-output.txt

@@ -2177,6 +2177,11 @@ node_mountstats_nfs_event_vfs_write_pages_total{export="192.168.1.1:/srv/test",m
 # TYPE node_mountstats_nfs_event_write_extension_total counter
 node_mountstats_nfs_event_write_extension_total{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",protocol="tcp"} 0
 node_mountstats_nfs_event_write_extension_total{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",protocol="udp"} 0
+# HELP node_mountstats_nfs_mountpoint_info Info metric for an NFS mountpoint.
+# TYPE node_mountstats_nfs_mountpoint_info gauge
+node_mountstats_nfs_mountpoint_info{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",mountpoint="/mnt/nfs/test",protocol="tcp"} 1
+node_mountstats_nfs_mountpoint_info{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",mountpoint="/mnt/nfs/test-dupe",protocol="tcp"} 1
+node_mountstats_nfs_mountpoint_info{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",mountpoint="/mnt/nfs/test-dupe",protocol="udp"} 1
 # HELP node_mountstats_nfs_operations_major_timeouts_total Number of times a request has had a major timeout for a given operation.
 # TYPE node_mountstats_nfs_operations_major_timeouts_total counter
 node_mountstats_nfs_operations_major_timeouts_total{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",operation="ACCESS",protocol="udp"} 0

collector/fixtures/e2e-output.txt

@@ -2209,6 +2209,11 @@ node_mountstats_nfs_event_vfs_write_pages_total{export="192.168.1.1:/srv/test",m
 # TYPE node_mountstats_nfs_event_write_extension_total counter
 node_mountstats_nfs_event_write_extension_total{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",protocol="tcp"} 0
 node_mountstats_nfs_event_write_extension_total{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",protocol="udp"} 0
+# HELP node_mountstats_nfs_mountpoint_info Info metric for an NFS mountpoint.
+# TYPE node_mountstats_nfs_mountpoint_info gauge
+node_mountstats_nfs_mountpoint_info{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",mountpoint="/mnt/nfs/test",protocol="tcp"} 1
+node_mountstats_nfs_mountpoint_info{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",mountpoint="/mnt/nfs/test-dupe",protocol="tcp"} 1
+node_mountstats_nfs_mountpoint_info{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",mountpoint="/mnt/nfs/test-dupe",protocol="udp"} 1
 # HELP node_mountstats_nfs_operations_major_timeouts_total Number of times a request has had a major timeout for a given operation.
 # TYPE node_mountstats_nfs_operations_major_timeouts_total counter
 node_mountstats_nfs_operations_major_timeouts_total{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",operation="ACCESS",protocol="udp"} 0

collector/fixtures/proc/10/mountinfo

@@ -3,5 +3,5 @@
 17 21 0:4 / /proc rw,nosuid,nodev,noexec,relatime shared:12 - proc proc rw
 21 0 8:1 / / rw,relatime shared:1 - ext4 /dev/sda1 rw,errors=remount-ro,data=ordered
 194 21 0:42 / /mnt/nfs/test rw shared:144 - nfs4 192.168.1.1:/srv/test rw,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,acregmin=3,acregmax=60,acdirmin=30,acdirmax=60,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.5,addr=192.168.1.1,local_lock=none
-177 21 0:42 / /mnt/nfs/test rw shared:130 - nfs4 192.168.1.1:/srv/test rw,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,acregmin=3,acregmax=60,acdirmin=30,acdirmax=60,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.5,addr=192.168.1.1,local_lock=none
-1398 798 0:44 / /mnt/nfs/test rw,relatime shared:1154 - nfs 192.168.1.1:/srv/test rw,vers=3,rsize=32768,wsize=32768,namlen=255,hard,proto=udp,timeo=11,retrans=3,sec=sys,mountaddr=192.168.1.1,mountvers=3,mountport=49602,mountproto=udp,local_lock=none,addr=192.168.1.1
+177 21 0:42 / /mnt/nfs/test-dupe rw shared:130 - nfs4 192.168.1.1:/srv/test rw,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,acregmin=3,acregmax=60,acdirmin=30,acdirmax=60,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.5,addr=192.168.1.1,local_lock=none
+1398 798 0:44 / /mnt/nfs/test-dupe rw,relatime shared:1154 - nfs 192.168.1.1:/srv/test rw,vers=3,rsize=32768,wsize=32768,namlen=255,hard,proto=udp,timeo=11,retrans=3,sec=sys,mountaddr=192.168.1.1,mountvers=3,mountport=49602,mountproto=udp,local_lock=none,addr=192.168.1.1

collector/mountstats_linux.go

@@ -32,6 +32,7 @@ var (
 type mountStatsCollector struct {
 	// General statistics
 	NFSAgeSecondsTotal *prometheus.Desc
+	NFSMountpointInfo  *prometheus.Desc
 
 	// Byte statistics
 	NFSReadBytesTotal        *prometheus.Desc
@@ -105,6 +106,13 @@ type nfsDeviceIdentifier struct {
 	MountAddress string
 }
 
+type nfsMountpointIdentifier struct {
+	Device       string
+	Protocol     string
+	MountAddress string
+	MountPoint   string
+}
+
 func init() {
 	registerCollector("mountstats", defaultDisabled, NewMountStatsCollector)
 }
@@ -127,9 +135,10 @@ func NewMountStatsCollector(logger *slog.Logger) (Collector, error) {
 	)
 
 	var (
-		labels      = []string{"export", "protocol", "mountaddr"}
-		opLabels    = []string{"export", "protocol", "mountaddr", "operation"}
-		translabels = []string{"export", "protocol", "mountaddr", "transport"}
+		labels          = []string{"export", "protocol", "mountaddr"}
+		infoLabels      = []string{"export", "protocol", "mountaddr", "mountpoint"}
+		opLabels        = []string{"export", "protocol", "mountaddr", "operation"}
+		transportLabels = []string{"export", "protocol", "mountaddr", "transport"}
 	)
 
 	return &mountStatsCollector{
@@ -140,6 +149,13 @@ func NewMountStatsCollector(logger *slog.Logger) (Collector, error) {
 			nil,
 		),
 
+		NFSMountpointInfo: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, subsystem, "mountpoint_info"),
+			"Info metric for an NFS mountpoint.",
+			infoLabels,
+			nil,
+		),
+
 		NFSReadBytesTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "read_bytes_total"),
 			"Number of bytes read using the read() syscall.",
@@ -199,70 +215,70 @@ func NewMountStatsCollector(logger *slog.Logger) (Collector, error) {
 		NFSTransportBindTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_bind_total"),
 			"Number of times the client has had to establish a connection from scratch to the NFS server.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
 		NFSTransportConnectTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_connect_total"),
 			"Number of times the client has made a TCP connection to the NFS server.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
 		NFSTransportIdleTimeSeconds: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_idle_time_seconds"),
 			"Duration since the NFS mount last saw any RPC traffic, in seconds.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
 		NFSTransportSendsTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_sends_total"),
 			"Number of RPC requests for this mount sent to the NFS server.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
 		NFSTransportReceivesTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_receives_total"),
 			"Number of RPC responses for this mount received from the NFS server.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
 		NFSTransportBadTransactionIDsTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_bad_transaction_ids_total"),
 			"Number of times the NFS server sent a response with a transaction ID unknown to this client.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
 		NFSTransportBacklogQueueTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_backlog_queue_total"),
 			"Total number of items added to the RPC backlog queue.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
 		NFSTransportMaximumRPCSlots: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_maximum_rpc_slots"),
 			"Maximum number of simultaneously active RPC requests ever used.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
 		NFSTransportSendingQueueTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_sending_queue_total"),
 			"Total number of items added to the RPC transmission sending queue.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
 		NFSTransportPendingQueueTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, subsystem, "transport_pending_queue_total"),
 			"Total number of items added to the RPC transmission pending queue.",
-			translabels,
+			transportLabels,
 			nil,
 		),
 
@@ -522,6 +538,7 @@ func (c *mountStatsCollector) Update(ch chan<- prometheus.Metric) error {
 
 	// store all seen nfsDeviceIdentifiers for deduplication
 	deviceList := make(map[nfsDeviceIdentifier]bool)
+	mountpointList := make(map[nfsMountpointIdentifier]bool)
 
 	for idx, m := range mounts {
 		// For the time being, only NFS statistics are available via this mechanism
@@ -531,6 +548,7 @@ func (c *mountStatsCollector) Update(ch chan<- prometheus.Metric) error {
 			continue
 		}
 
+		mountPoint := m.Mount
 		var mountAddress string
 		if idx < len(mountsInfo) {
 			// The mount entry order in the /proc/self/mountstats and /proc/self/mountinfo is the same.
@@ -539,6 +557,14 @@ func (c *mountStatsCollector) Update(ch chan<- prometheus.Metric) error {
 		}
 
 		for k := range stats.Transport {
+			mountpointIdentifier := nfsMountpointIdentifier{m.Device, stats.Transport[k].Protocol, mountAddress, mountPoint}
+			if mountpointList[mountpointIdentifier] {
+				c.logger.Debug("Skipping duplicate mountpoint info entry", "device", mountpointIdentifier)
+			} else {
+				mountpointList[mountpointIdentifier] = true
+				c.updateNFSMountpointInfo(ch, m.Device, stats.Transport[k].Protocol, mountAddress, mountPoint)
+			}
+
 			deviceIdentifier := nfsDeviceIdentifier{m.Device, stats.Transport[k].Protocol, mountAddress}
 			i := deviceList[deviceIdentifier]
 			if i {
@@ -553,6 +579,15 @@ func (c *mountStatsCollector) Update(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+func (c *mountStatsCollector) updateNFSMountpointInfo(ch chan<- prometheus.Metric, export, protocol, mountAddress, mountPoint string) {
+	ch <- prometheus.MustNewConstMetric(
+		c.NFSMountpointInfo,
+		prometheus.GaugeValue,
+		1,
+		export, protocol, mountAddress, mountPoint,
+	)
+}
+
 func (c *mountStatsCollector) updateNFSStats(ch chan<- prometheus.Metric, s *procfs.MountStatsNFS, export, protocol, mountAddress string) {
 	labelValues := []string{export, protocol, mountAddress}
 	ch <- prometheus.MustNewConstMetric(

collector/mountstats_linux_test.go

@@ -0,0 +1,79 @@
+// Copyright The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !nomountstats
+
+package collector
+
+import (
+	"io"
+	"log/slog"
+	"strings"
+	"testing"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/testutil"
+)
+
+type testMountStatsCollector struct {
+	c Collector
+}
+
+func (c testMountStatsCollector) Collect(ch chan<- prometheus.Metric) {
+	c.c.Update(ch)
+}
+
+func (c testMountStatsCollector) Describe(ch chan<- *prometheus.Desc) {
+	prometheus.DescribeByCollect(c, ch)
+}
+
+func NewTestMountStatsCollector(logger *slog.Logger) (prometheus.Collector, error) {
+	c, err := NewMountStatsCollector(logger)
+	if err != nil {
+		return testMountStatsCollector{}, err
+	}
+	return testMountStatsCollector{c: c}, nil
+}
+
+func TestMountStatsMountPointInfo(t *testing.T) {
+	*procPath = "fixtures/proc"
+
+	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
+	c, err := NewTestMountStatsCollector(logger)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	reg := prometheus.NewPedanticRegistry()
+	reg.MustRegister(c)
+
+	expected := `# HELP node_mountstats_nfs_age_seconds_total The age of the NFS mount in seconds.
+# TYPE node_mountstats_nfs_age_seconds_total counter
+node_mountstats_nfs_age_seconds_total{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",protocol="tcp"} 13968
+node_mountstats_nfs_age_seconds_total{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",protocol="udp"} 13968
+# HELP node_mountstats_nfs_mountpoint_info Info metric for an NFS mountpoint.
+# TYPE node_mountstats_nfs_mountpoint_info gauge
+node_mountstats_nfs_mountpoint_info{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",mountpoint="/mnt/nfs/test",protocol="tcp"} 1
+node_mountstats_nfs_mountpoint_info{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",mountpoint="/mnt/nfs/test-dupe",protocol="tcp"} 1
+node_mountstats_nfs_mountpoint_info{export="192.168.1.1:/srv/test",mountaddr="192.168.1.1",mountpoint="/mnt/nfs/test-dupe",protocol="udp"} 1
+`
+
+	if err := testutil.GatherAndCompare(
+		reg,
+		strings.NewReader(expected),
+		"node_mountstats_nfs_age_seconds_total",
+		"node_mountstats_nfs_mountpoint_info",
+	); err != nil {
+		t.Fatal(err)
+	}
+}