Webアプリケーション（投稿フォーム）を作成するために、MongoDBからデータを取得したいのですが、できません

Question

前提・実現したいこと

Webアプリケーション（投稿フォーム）を作成するために、MongoDBからデータを取得したいのですが、できません

※使用OS：MacOS

発生している問題・エラーメッセージ

ターミナルで、node app.js と入力したところ、以下のエラーメッセージが表示されました

body-parser deprecated bodyParser: use individual json/urlencoded middlewares app.js:34:9
body-parser deprecated undefined extended: provide extended option node_modules/body-parser/index.js:105:29
{ MongoNetworkError: failed to connect to server [localhost:27017] on first connect [MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017]
    at Pool.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/topologies/server.js:503:11)
    at Pool.emit (events.js:160:13)
    at Connection.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/connection/pool.js:326:12)
    at Object.onceWrapper (events.js:255:19)
    at Connection.emit (events.js:160:13)
    at Socket.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/connection/connection.js:245:50)
    at Object.onceWrapper (events.js:255:19)
    at Socket.emit (events.js:160:13)
    at emitErrorNT (internal/streams/destroy.js:64:8)
    at process._tickCallback (internal/process/next_tick.js:152:19)
  name: 'MongoNetworkError',
  message: 'failed to connect to server [localhost:27017] on first connect [MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017]' }
(node:12546) UnhandledPromiseRejectionWarning: MongoNetworkError: failed to connect to server [localhost:27017] on first connect [MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017]
    at Pool.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/topologies/server.js:503:11)
    at Pool.emit (events.js:160:13)
    at Connection.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/connection/pool.js:326:12)
    at Object.onceWrapper (events.js:255:19)
    at Connection.emit (events.js:160:13)
    at Socket.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/connection/connection.js:245:50)
    at Object.onceWrapper (events.js:255:19)
    at Socket.emit (events.js:160:13)
    at emitErrorNT (internal/streams/destroy.js:64:8)
    at process._tickCallback (internal/process/next_tick.js:152:19)
(node:12546) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:12546) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

2018.3.7
いただいた回答の通り、mongodコマンドを入力してみましたが、未だ解決できず...

1.mongod入力

2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten] MongoDB starting : pid=663 port=27017 dbpath=/data/db 64-bit host=ICHIHANAMBA.local
2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten] db version v3.6.2
2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten] git version: 489d177dbd0f0420a8ca04d39fd78d0a2c539420
2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten] OpenSSL version: OpenSSL 1.0.2n  7 Dec 2017
2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten] allocator: system
2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten] modules: none
2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten] build environment:
2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten]     distarch: x86_64
2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten]     target_arch: x86_64
2018-03-07T04:55:34.304+0900 I CONTROL  [initandlisten] options: {}
2018-03-07T04:55:34.307+0900 I STORAGE  [initandlisten] exception in initAndListen: NonExistentPath: Data directory /data/db not found., terminating
2018-03-07T04:55:34.307+0900 I CONTROL  [initandlisten] now exiting
2018-03-07T04:55:34.307+0900 I CONTROL  [initandlisten] shutting down with code:100

2.touch app.js、node app.jsコマンド入力

body-parser deprecated bodyParser: use individual json/urlencoded middlewares app.js:34:9
body-parser deprecated undefined extended: provide extended option node_modules/body-parser/index.js:105:29
{ MongoNetworkError: failed to connect to server [localhost:27017] on first connect [MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017]
    at Pool.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/topologies/server.js:503:11)
    at Pool.emit (events.js:160:13)
    at Connection.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/connection/pool.js:326:12)
    at Object.onceWrapper (events.js:255:19)
    at Connection.emit (events.js:160:13)
    at Socket.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/connection/connection.js:245:50)
    at Object.onceWrapper (events.js:255:19)
    at Socket.emit (events.js:160:13)
    at emitErrorNT (internal/streams/destroy.js:64:8)
    at process._tickCallback (internal/process/next_tick.js:152:19)
  name: 'MongoNetworkError',
  message: 'failed to connect to server [localhost:27017] on first connect [MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017]' }
(node:666) UnhandledPromiseRejectionWarning: MongoNetworkError: failed to connect to server [localhost:27017] on first connect [MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017]
    at Pool.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/topologies/server.js:503:11)
    at Pool.emit (events.js:160:13)
    at Connection.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/connection/pool.js:326:12)
    at Object.onceWrapper (events.js:255:19)
    at Connection.emit (events.js:160:13)
    at Socket.<anonymous> (/Users/miwaichihana/hoge/node_modules/mongodb-core/lib/connection/connection.js:245:50)
    at Object.onceWrapper (events.js:255:19)
    at Socket.emit (events.js:160:13)
    at emitErrorNT (internal/streams/destroy.js:64:8)
    at process._tickCallback (internal/process/next_tick.js:152:19)
(node:666) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:666) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

該当のソースコード

■app.jsファイル

"use strict";

var http = require('http');

var express = require('express');

var path = require('path');

var bodyparser = require('body-parser');

var mongoose = require('mongoose');

var Message = require('./schema/Message');

var app = express();

mongoose.connect('mongodb://localhost:27017/chatapp', function(err){

  if(err){

    console.error(err);

  }else{

    console.log("successfully connected to MongoDB.");

  }
});

app.use(bodyparser())

app.set('views', path.join(__dirname, 'views'));

app.set('view engine', 'pug');

app.get("/", function(req, res, next){

  Message.find({}, function(err, msgs){

    if(err) throw err;

    return res.render('index', {messages : msgs});

  });

});

app.get("/update", function(req, res, next){

  return res.render('update');

});

app.post("/update", function(req, res, next){

  var newMessage = new Message({

    username : req.body.username,
    message : req.body.message

  });

  newMessage.save((err) => {

    if(err)throw err;
    return res.redirect("/");

  });
});

var server = http.createServer(app);

server.listen('3000');

■schemaフォルダ > Message.jsファイル

var mongoose = require('mongoose');

var Message = mongoose.Schema({

  username : String,
  message : String,
  date : {type : Date, default : new Date()}

});

module.exports = mongoose.model('Message', Message)

■viewsフォルダ　> index.pugファイル

<!DOCTYPE html>
<html lang="ja">
	<head>
		<meta charset="utf-8">
	</head>
	<body>
		<h1>投稿一覧</h1>
		<section>
			each msg in messages
				<div>
					<h2>#{msg.username}</h2>
					<time>#{msg.date}</time>
					<p>#{msg.message}</p>
				</div>
		</section>
	</body>
</html>

■viewsフォルダ　> update.pugファイル

<!DOCTYPE html>
<html lang="ja">
  <head>
    <meta charset="utf-8">
  </head>
  <body>
    <h1>メッセージを保存</h1>
    <form action="update" method="POST">
      <input type="text" name="username" placeholder="名前">
      <textarea placeholder="メッセージ" name="message"></textarea>
      <button type="submit">送信</button>
    </form>
  </body>
</html>

Answer 1

MongoNetworkError: failed to connect to server [localhost:27017] on first connect [MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017]

mongo database自体を起動していないのではないでしょうか？

mongodでmongo databaseは起動しましたか？

更新 - 20180307 - 17:28

2018-03-07T04:55:34.307+0900 I STORAGE  [initandlisten] exception in initAndListen: NonExistentPath: Data directory /data/db not found., terminating

mongoDBがデータを保存する場所が未作成のようです。

デフォルトでは保存先は/data/dbなので、とりあえず保存先を以下のようなかたちで作成する必要があります。

sudo mkdir -p /data/db

その後、作成したディレクトリに書き込み権限を与える必要があるので、以下を実行します。

whoami
whoamiの結果

whoamiのところにはユーザー名が表示されます。

sudo chown -Rv whoamiの結果 /data/db

whoamiで表示されたユーザーに書き込み権限を与える

とりあえず上記試してみて下さい。それでもエラーがある場合はまた他の対応がひつようになってくるとおもいます。

Comments

[Miwa_Ichihana]

ご回答ありがとうございます！
また、返信が遅くなり大変申し訳ありませんでした。
mongodコマンドを入力してみましたが、解決には至らず...でした。

2018.3.7「発生している問題・エラーメッセージ」欄に追記しました。
また、ご回答・アドバイスなどいただければ幸いです。

[Miwa_Ichihana]

教えていただいたコマンドを入力することで解決できました！
ありがとうございます！
また、機会があればよろしくお願いいたします！

[HayatoKamono]

お、よかったです！