PT-1738 - add mongos to pt-mongodb-summary

src/go/pt-mongodb-summary/README.rst

@@ -59,6 +59,12 @@ Output example
 
 .. code-block:: none
 
+   # Mongos #################################################################################################
+   Host                              LastPing                     Version         Uptime (sec)
+   my-cluster-name-mongos-0:27017    2026-02-16T13:01:22Z         8.0.17-6        3553           
+   my-cluster-name-mongos-1:27017    2026-02-16T13:01:26Z         8.0.17-6        3543           
+   my-cluster-name-mongos-2:27017    2026-02-16T13:01:28Z         8.0.17-6        3533           
+
    # Instances ####################################################################################
    ID    Host                         Type                                 ReplSet
     0 localhost:17001                PRIMARY                                r1

src/go/pt-mongodb-summary/main.go

@@ -15,6 +15,7 @@ package main
 
 import (
 	"bytes"
+	"cmp"
 	"context"
 	"crypto/tls"
 	"crypto/x509"
@@ -26,6 +27,7 @@ import (
 	"os"
 	"os/user"
 	"path/filepath"
+	"slices"
 	"strings"
 	"time"
 
@@ -35,6 +37,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/shirou/gopsutil/process"
 	log "github.com/sirupsen/logrus"
+	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/bson/primitive"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
@@ -159,6 +162,29 @@ type clusterwideInfo struct {
 	Chunks                  []proto.ChunksByCollection
 }
 
+type mongosInstance struct {
+	Name     string    `bson:"_id"`
+	LastPing time.Time `bson:"ping"`
+	UpTime   int       `bson:"up"`
+	Version  string    `bson:"mongoVersion"`
+}
+
+type mongosInfo struct {
+	Instances []mongosInstance `bson:"instances"`
+}
+
+func (t mongosInfo) MaxNameLen() int {
+	if len(t.Instances) == 0 {
+		return 0
+	}
+
+	maxInst := slices.MaxFunc(t.Instances, func(a, b mongosInstance) int {
+		return cmp.Compare(len(a.Name), len(b.Name))
+	})
+
+	return len(maxInst.Name)
+}
+
 type cliOptions struct {
 	Host               string
 	User               string
@@ -184,6 +210,7 @@ type collectedInfo struct {
 	RunningOps       *opCounters
 	SecuritySettings *security
 	HostInfo         *hostInfo
+	MongosInfo       *mongosInfo
 	Errors           []string
 }
 
@@ -256,14 +283,19 @@ func main() {
 
 	ci := &collectedInfo{}
 
+	ci.MongosInfo, err = getMongosInfo(ctx, client)
+	if err != nil {
+		log.Warnf("[Warning] cannot get mongos info: %v\n", err)
+	}
+
 	ci.HostInfo, err = getHostInfo(ctx, client)
 	if err != nil {
 		log.Errorf("Cannot get host info for %q: %s", opts.Host, err)
 		os.Exit(cannotGetHostInfo) //nolint:gocritic
 	}
 
 	if ci.ReplicaMembers, err = util.GetReplicasetMembers(ctx, clientOptions); err != nil {
-		log.Warnf("[Error] cannot get replicaset members: %v\n", err)
+		log.Warnf("[Warning] cannot get replicaset members: %v\n", err)
 	}
 
 	log.Debugf("replicaMembers:\n%+v\n", ci.ReplicaMembers)
@@ -332,7 +364,12 @@ func formatResults(ci *collectedInfo, format string) ([]byte, error) {
 	default:
 		buf = new(bytes.Buffer)
 
-		t := template.Must(template.New("replicas").Parse(templates.Replicas))
+		t := template.Must(template.New("mongos").Parse(templates.MongosInfo))
+		if err := t.Execute(buf, ci.MongosInfo); err != nil {
+			return nil, errors.Wrap(err, "cannot parse mongos section of the output template")
+		}
+
+		t = template.Must(template.New("replicas").Parse(templates.Replicas))
 		if err := t.Execute(buf, ci.ReplicaMembers); err != nil {
 			return nil, errors.Wrap(err, "cannot parse replicas section of the output template")
 		}
@@ -454,6 +491,29 @@ func countMongodProcesses() (int, error) {
 	return count, nil
 }
 
+func getMongosInfo(ctx context.Context, client *mongo.Client) (*mongosInfo, error) {
+	threshold := time.Now().Add(-300 * time.Second)
+
+	filter := bson.M{
+		"ping": bson.M{
+			"$gt": threshold,
+		},
+	}
+
+	cursor, err := client.Database("config").Collection("mongos").Find(ctx, filter)
+	if err != nil {
+		return nil, fmt.Errorf("failed to find mongos: %w", err)
+	}
+	defer cursor.Close(ctx)
+
+	var instances []mongosInstance
+	if err := cursor.All(ctx, &instances); err != nil {
+		return nil, fmt.Errorf("failed to decode mongos: %w", err)
+	}
+
+	return &mongosInfo{Instances: instances}, nil
+}
+
 func getClusterwideInfo(ctx context.Context, client *mongo.Client) (*clusterwideInfo, error) {
 	var databases databases
 

src/go/pt-mongodb-summary/main_test.go

@@ -151,3 +151,23 @@ func TestParseArgs(t *testing.T) {
 
 	os.Stdout = old
 }
+
+func TestGetMongosInfo(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	client, err := tu.TestClient(ctx, tu.MongoDBMongosPort)
+	require.NoError(t, err)
+
+	info, err := getMongosInfo(ctx, client)
+	require.NoError(t, err)
+	require.NotNil(t, info)
+	require.NotEmpty(t, info.Instances)
+
+	for _, m := range info.Instances {
+		require.NotEmpty(t, m.Name)
+		require.NotEmpty(t, m.Version)
+		require.NotEqual(t, 0, m.UpTime)
+		require.False(t, m.LastPing.IsZero())
+	}
+}

src/go/pt-mongodb-summary/templates/mongos.go

@@ -0,0 +1,37 @@
+// This program is copyright 2016-2026 Percona LLC and/or its affiliates.
+//
+// THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
+// WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+//
+// This program is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free Software
+// Foundation, version 2.
+//
+// You should have received a copy of the GNU General Public License, version 2
+// along with this program; if not, see <https://www.gnu.org/licenses/>.
+
+package templates
+
+const MongosInfo = `
+# Mongos #################################################################################################
+{{ "" }}
+{{- $padding := "    " -}}
+{{- $timeWidth := 20 -}}
+{{- $hostWidth := .MaxNameLen -}}
+{{- $versionWidth := 15 -}}
+
+{{ printf "%-*s" $hostWidth "Host" }}{{ $padding }}
+{{- printf "%-*s" $timeWidth "LastPing" }}{{ $padding }}
+{{- printf "%-*s" $versionWidth "Version" }}{{ $padding }}Uptime (sec)
+{{ if .Instances -}}
+{{- range .Instances -}}
+{{ printf "%-*s" $hostWidth .Name }}{{ $padding }}
+{{- printf "%-*s" $timeWidth (.LastPing.Format "2006-01-02T15:04:05Z07:00") }}{{ $padding }}
+{{- printf "%-*s" $versionWidth .Version }}{{ $padding }}
+{{- printf "%-15d" .UpTime }}
+{{ end }}
+{{- else -}}
+                                        no mongos instances found
+{{- end }}
+`