regular Rails appplication pipeline with docker build

.gitlab-ci.yml

---
stages:
- ".pre"
- build
- test
- release
- ".post"
variables:
  RUBY_VERSION: 2.7.2
  POSTGRES_DB: "$CI_PROJECT_NAME"
  DATABASE_NAME: "$CI_PROJECT_NAME"
  POSTGRES_USER: postgres
  DATABASE_HOST: postgres
  POSTGRES_PASSWORD: postgres
  POSTGRES_INITDB_ARGS: "--encoding=UTF8 --data-checksums"
  POSTGRES_HOST_AUTH_METHOD: trust
.job_template:
  image: ruby:$RUBY_VERSION
  tags:
  - docker
  services:
  - postgres:12
  before_script:
  - curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add -
  - echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list
  - curl -sL https://deb.nodesource.com/setup_14.x | bash -
  - apt-get update && apt-get install -y nodejs yarn firefox-esr
  - curl -sL "https://github.com/mozilla/geckodriver/releases/download/v0.28.0/geckodriver-v0.28.0-linux64.tar.gz"
    | tar -xz -C /usr/local/bin
  - yarn install
  - bundle config set deployment 'true'
  - bundle install
  - bundle exec rails db:setup
cache:
  key: "$CI_PROJECT_NAME-$RUBY_VERSION"
  paths:
  - vendor/bundle
  - vendor/ruby
  - ".bundle"
  - node_modules
build assets:
  extends: ".job_template"
  stage: build
  script:
  - bundle exec rails assets:precompile
  artifacts:
    paths:
    - public/assets
    - public/packs
    expire_in: 1 day
rspec:
  extends: .job_template
  stage: test
  script:
  - bundle exec rspec
jest:
  extends: .job_template
  stage: test
  script:
  - yarn test
package assets:
  stage: release
  only:
  - master
  image: curlimages/curl:latest
  variables:
    PACKAGE_NAME: assets.tar.gz
  script:
  - tar -czf ./$PACKAGE_NAME public/{assets,packs}
  - curl --header "JOB-TOKEN:$CI_JOB_TOKEN" --upload-file ./$PACKAGE_NAME ${CI_API_V4_URL}/projects/${CI_PROJECT_ID}/packages/generic/$CI_PROJECT_NAME_assets/1.0.0/$PACKAGE_NAME
build image:
  stage: release
  only:
  - master
  variables:
    IMAGE_TAG: "$CI_REGISTRY_IMAGE"
  script:
  - export RELEASE_IMAGE_TAG=$IMAGE_TAG:$(date +%F)
  - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
  - docker build -t $RELEASE_IMAGE_TAG .
  - docker push $RELEASE_IMAGE_TAG
  - docker tag $RELEASE_IMAGE_TAG $IMAGE_TAG:latest
  - docker push $IMAGE_TAG:latest