log MongoDB driver version

monstache.go

@@ -11,10 +11,27 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"io/ioutil"
+	"log"
+	"math"
+	"net/http"
+	"net/http/pprof"
+	"os"
+	"os/signal"
+	"plugin"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+	"text/template"
+	"time"
+
 	"github.com/BurntSushi/toml"
 	"github.com/aws/aws-sdk-go/aws/credentials"
 	"github.com/coreos/go-systemd/daemon"
-	"github.com/evanphx/json-patch"
+	jsonpatch "github.com/evanphx/json-patch"
 	"github.com/olivere/elastic"
 	aws "github.com/olivere/elastic/aws/v4"
 	"github.com/robertkrimen/otto"
@@ -28,24 +45,9 @@ import (
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/gridfs"
 	"go.mongodb.org/mongo-driver/mongo/options"
+	mongoversion "go.mongodb.org/mongo-driver/version"
 	"gopkg.in/Graylog2/go-gelf.v2/gelf"
 	"gopkg.in/natefinch/lumberjack.v2"
-	"io/ioutil"
-	"log"
-	"math"
-	"net/http"
-	"net/http/pprof"
-	"os"
-	"os/signal"
-	"plugin"
-	"reflect"
-	"regexp"
-	"strconv"
-	"strings"
-	"sync"
-	"syscall"
-	"text/template"
-	"time"
 )
 
 var infoLog = log.New(os.Stdout, "INFO ", log.Flags())
@@ -4366,6 +4368,7 @@ func buildMongoClient(config *configOptions) *mongo.Client {
 			cleanMongoURL(config.MongoURL), err)
 	}
 	infoLog.Printf("Started monstache version %s", version)
+	infoLog.Printf("MongoDB go driver %s", mongoversion.Driver)
 	if mongoInfo, err := getBuildInfo(mongoClient); err == nil {
 		infoLog.Printf("Successfully connected to MongoDB version %s", mongoInfo.Version)
 	} else {