Unable to connect to mysql

Hello, I am trying to use Gitlab CI. My .gitlab-ci.yml is as follows.

The error i keep on getting is “SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Name or service not known”

# Select image from https://hub.docker.com/_/php/
image: php:7.1.17

# Select what we should cache between builds
cache:
  paths:
  - vendor/

before_script:
- apt-get update -yqq
- apt-get install -yqq git libmcrypt-dev libpq-dev libcurl4-gnutls-dev libicu-dev libvpx-dev libjpeg-dev libpng-dev libxpm-dev zlib1g-dev libfreetype6-dev libxml2-dev libexpat1-dev libbz2-dev libgmp3-dev libldap2-dev unixodbc-dev libsqlite3-dev libaspell-dev libsnmp-dev libpcre3-dev libtidy-dev
# Install PHP extensions
- docker-php-ext-install mbstring mcrypt curl json intl gd xml zip bz2 opcache pdo_mysql
# Install & enable Xdebug for code coverage reports
- pecl install xdebug
- docker-php-ext-enable xdebug
# Install and run Composer
- curl -sS https://getcomposer.org/installer | php
- php composer.phar install

# Bring in any services we need http://docs.gitlab.com/ee/ci/docker/using_docker_images.html#what-is-a-service
# See http://docs.gitlab.com/ce/ci/services/README.html for examples.
services:
- name: mysql:latest
  alias: mysql
  command: ["mysql", "-u", "root", "-p", "mondo_unittest", "<", "./test/mondo_unittest.sql"]

# Set any variables we need
variables:
  # Configure mysql environment variables (https://hub.docker.com/r/_/mysql/)
  MYSQL_ROOT_PASSWORD: password
  MYSQL_DATABASE: mondo_unittest

# Run our tests
# If Xdebug was installed you can generate a coverage report and see code coverage metrics.
test:
  script:
   vendor/bin/phpunit --configuration phpunit.xml --coverage-text --colors=never