Golang 无法在 MongoDB 中创建文档

我正在try 将文档插入到MongoDB中，但尽管成功连接到Mongo，我仍然收到以下错误:

http: panic serving 172.27.0.8:40176: runtime error: invalid memory address or nil pointer dereference

我的Main.Go我正在初始化一个数据库连接，如下所示

func main(){
   
      //Connect to mongo
      mongoClient,err:=connectToMongo()
      if err!=nil{
          log.Panic(err)
      }
      client=mongoClient
  
      //Create a context that mongo needs in order to disconnect
      ctx,_:=context.WithTimeout(context.Background(), 15*time.Second)
     // ctx,cancel:=context.WithTimeout(context.Background(), 15*time.Second)
      //defer cancel()
      
  
      //close connection
      defer func ()  {
          if err =client.Disconnect(ctx); err!=nil{
              panic(err)
          }
      }() 

    muxRouter := mux.NewRouter().StrictSlash(true)

    //specify who's allowed to connect
    c:=cors.New(cors.Options{ 
        AllowedOrigins: []string{"https://*", "http://*"},
        AllowedMethods: []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
        AllowedHeaders: []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
        ExposedHeaders: []string{"Link"},
        AllowCredentials: true,
        MaxAge: 300,
})
    router := AddRoutes(muxRouter)
    handler := c.Handler(router)
    log.Println("Service stratring at o  port ",webPort)

    sterr := http.ListenAndServe(":9090", handler) //Uncomment this line when using docker
    if sterr != nil {
        log.Fatal("error starting http server :: ", err)
        return
    }

    log.Println("Service started at port ",webPort)


    
  

}

func connectToMongo()(*mongo.Client,error){
    mongoUsername := os.Getenv("MONGOUSERNAME")
    mongoPassword := os.Getenv("MONGOPASSWORD")
    //create connection options
    clientOptions:=options.Client().ApplyURI(mongoURL)
    clientOptions.SetAuth(options.Credential{
        Username: mongoUsername,
        Password: mongoPassword,
    })

    //connect
    c,err:=mongo.Connect(context.TODO(),clientOptions)
    if err!=nil{
        log.Println("Error connecting to mongo",err)
        return nil,err
    }
    log.Println("Connected to mongo")
    return c,nil
}

在一个单独的文件中，Models.go是我try 将数据插入数据库的位置，如下所示:

var client *mongo.Client
func  Insert(entry LogEntry)error{
    log.Printf("Attempting to insert %s", entry)
    log.Printf("client s  %s", client)
    //db:=client.Database("logs")
    //log.Printf("database  is  %s", db)
    
   collection:=client.Database("logs").Collection("logsCollection")
    log.Printf("collection is  %s", collection)

    _,err :=collection.InsertOne(context.TODO(), LogEntry{
        Name: entry.Name,
        Data: entry.Data,
        CreatedAt: time.Now(),
        UpdatedAt: time.Now(),
    })
    if err!=nil{
        log.Println("Error inserting new record into logs collection",err)
        return err
    }
    log.Println("insert successful")
    return nil
}

有谁能发现我做错了什么吗？