Gitlab services mssql microsoft express db

docker

#1
Build & Test:
  extends: .build_job
  variables:
    SA_PASSWORD: <S00p3rS3cUr3>
    ACCEPT_EULA: Y
  services:
    - microsoft/mssql-server-linux
  only:
    - master

Trying to use services to start mssql db docker. But, how to access this db ? what would be the hostname and the port

Thank you