无法将gitlab CI连接到mongoDB

Question

在尝试运行管道时遇到错误，连接ECONNREFUSED 127.0.0.1:27017

yml文件配置

image: node:latest

cache:
  paths:
  - server/node_modules/

services:
  - mongo

variables:
  MONGO_URI: 'mongodb://mongo/db_name'
  NODE_ENV: 'test'

testing:
  script:
   - cd server
   - npm install
   - npm test