Mongo-Driver Should I use InsertMany or InsertOne - mongodb

Question

I am creating a Rest CRUD HTTP server written in Go. My error is I am getting this message from the database connection: "context deadline exceeded".
I have a CreateUsers() function to insert multiple users into the database. Currently, I am inserting one user at time:
func CreateUsers(users []*models.User) ([]primitive.ObjectID, error) {
client, ctx, cancel := database.GetConnection()
defer cancel()
defer client.Disconnect(ctx)
var userIds []primitive.ObjectID
if len(users) == 0 {
log.Printf("No users to create")
return userIds, errors.New("no users to create")
}
for _, user := range users {
user.ID = primitive.NewObjectID()
hashedPassword, err := utils.HashPassword(user.Password)
if err != nil {
log.Printf("Error while hashing password: %v", err)
return userIds, err
}
user.Password = hashedPassword
result, err := client.Database("users").Collection("users").InsertOne(ctx, user)
if err != nil {
log.Printf("Error while creating user: %v", err)
return userIds, err
}
oid := result.InsertedID.(primitive.ObjectID)
userIds = append(userIds, oid)
}
return userIds, nil
}
My database connection (database.GetConnection) is something like:
func GetConnection() (*mongo.Client, context.Context, context.CancelFunc) {
client, err := mongo.NewClient(options.Client().ApplyURI(connectionURI))
if err != nil {
log.Fatalf("error while creating client: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), connectionTimeout*time.Second)
err = client.Connect(ctx)
if err != nil {
log.Fatalf("cluster connection error: %v", err)
}
err = client.Ping(ctx, nil)
if err != nil {
log.Fatalf("cluster ping error")
}
log.Println("connected to mongodb")
return client, ctx, cancel
}
Note: connectionTimeout is equal to 5.
I am not sure but the time exceeded error may be related to the InsertOne() approach. So, instead of focusing in solving that error I should be asking how to parse the []models.User into bson.D{} documents to pass them as parameters to InsertMany().
I think another advantage of using InsertMany approach is the query time will be way below. Any suggestions?