Let’s Chat 起動できない

前提・実現したいこと

チャットツールのLet's chatをインストールしたのですが、このようなエラーが発生しました。

発生している問題・エラーメッセージ

オープンソースLet’s Chatをインストールしてみる
npm start をした後です。


(node:12359) DeprecationWarning: `open()` is deprecated in mongoose >= 4.11.0, use `openUri()` instead, or set the `useMongoClient` option if using `connect()` or `createConnection()`. See http://mongoosejs.com/docs/4.x/docs/connections.html#use-mongo-client

/root/lets-chat/node_modules/mongodb/lib/mongo_client.js:421
          throw err
          ^
MongoError: failed to connect to server [localhost:27017] on first connect [MongoError: connect ECONNREFUSED 127.0.0.1:27017]
    at Pool.<anonymous> (/root/lets-chat/node_modules/mongodb-core/lib/topologies/server.js:336:35)
    at emitOne (events.js:96:13)
    at Pool.emit (events.js:188:7)
    at Connection.<anonymous> (/root/lets-chat/node_modules/mongodb-core/lib/connection/pool.js:280:12)
    at Connection.g (events.js:292:16)
    at emitTwo (events.js:106:13)
    at Connection.emit (events.js:191:7)
    at Socket.<anonymous> (/root/lets-chat/node_modules/mongodb-core/lib/connection/connection.js:189:49)
    at Socket.g (events.js:292:16)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:188:7)
    at emitErrorNT (net.js:1290:8)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)

npm ERR! Linux 2.6.32-754.2.1.el6.x86_64
npm ERR! argv "/root/.nvm/versions/node/v6.14.4/bin/node" "/root/.nvm/versions/node/v6.14.4/bin/npm" "start"
npm ERR! node v6.14.4
npm ERR! npm  v3.10.10
npm ERR! code ELIFECYCLE
npm ERR! lets-chat@0.4.8 start: `node app.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the lets-chat@0.4.8 start script 'node app.js'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the lets-chat package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     node app.js
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs lets-chat
npm ERR! Or if that isn't available, you can get their info via:
npm ERR!     npm owner ls lets-chat
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR!     /root/lets-chat/npm-debug.log