firebase_gitlab_cicd.yml

# Note:
#
# Only hosting and functions are getting deployed in this 
# script you should only deploy whole firebase project,
# If you are maintaining local copy of indexes and rules.
# 
# Assuming that you have functions folder in your roote folder.
#
# This pipe line reads credentials from the gitlab envrioment.
# https://docs.gitlab.com/ee/ci/variables/README.html#create-a-custom-variable-in-the-ui

image: node:latest

stages:
  - release

test:
  stage: release
  before_script:
    - npm install -g firebase-tools
    - npm install ./functions
  script:
    - firebase use [your-project-name]
    - firebase deploy --only hosting 
    - firebase deploy --only functions
  environment: [envrioment from where to read the credentils]
  only:
    - [branch name which can trigger this pipeline]