CI can't connect to MongoDB

Summary

Gitlab CE's CI is not connecting to MongoDB.

Steps to reproduce

Run a Node project in CE CI with a .gitlab-ci.yml file like this:

image: node:latest

cache:
 paths:
  - node_modules/

services:
 - redis
 - mongo

before_script:
 - npm i --silent

tests:
 script:
  - npm test

What is the current bug behavior?

When testing starts and the app is loaded, connecting to the DB goes wrong: ✗ MongoDB connection error. Please make sure MongoDB is running.

What is the expected correct behavior?

It should show a successful connection message, and continue to run the tests.

Relevant logs and/or screenshots

> mocha --reporter spec --timeout 5000

  GET /
node_redis: Warning: Redis server does not require a password, but a password was supplied.
✗ MongoDB connection error. Please make sure MongoDB is running.

The Redis warning is because CI is running no passwords, while my own setup does have one. Same goes for Mongo.