loopback mongodb Authentication failed
<p>I have an empty loopback app,
where I added a model and a mongodb datasource.</p>

<p>When connecting, I get the following error:</p>

<pre><code>Web server listening at: http://0.0.0.0:3000
Browse your REST API at http://0.0.0.0:3000/explorer
Connection fails:  { [MongoError: Authentication failed.]
  name: 'MongoError',
  message: 'Authentication failed.',
  ok: 0,
  code: 18,
  errmsg: 'Authentication failed.' }
It will be retried for the next request.

/media/[...]/node_modules/mongodb/lib/mongo_client.js:454
              throw err
              ^
MongoError: Authentication failed.
    at Function.MongoError.create (/media/[...]/node_modules/mongodb-core/lib/error.js:31:11)
    at /media/[...]/node_modules/mongodb-core/lib/topologies/server.js:778:66
    at Callbacks.emit (/media/[...]/node_modules/mongodb-core/lib/topologies/server.js:95:3)
    at null.messageHandler (/media/[...]/node_modules/mongodb-core/lib/topologies/server.js:249:23)
    at Socket.&lt;anonymous&gt; (/media/[...]/node_modules/mongodb-core/lib/connection/connection.js:265:22)
    at emitOne (events.js:77:13)
    at Socket.emit (events.js:169:7)
    at readableAddChunk (_stream_readable.js:153:18)
    at Socket.Readable.push (_stream_readable.js:111:10)
    at TCP.onread (net.js:531:20)
</code></pre>

<p>The db runs in a docker. I can connect to it via "MongoClient"</p>

<p>datasources.js:</p>

<pre><code>{
    "mongodb_dev": {
        "name": "mongodb_dev",
        "connector": "mongodb",
        "host": "127.0.0.1",
        "database": "some-db",
        "username": "mongouser",
        "password": "pass",
        "port": 27017
    }
}
</code></pre>