MkDocs with plugins in GitLab CI (with apk and pip packages caching)

.gitlab-ci.yml

image: python:alpine
variables:
  PIP_CACHE_DIR: $CI_PROJECT_DIR/.cache/pip
  APK_CACHE_DIR: $CI_PROJECT_DIR/.cache/apk
  PIP_PACKAGES:
    mkdocs
    mkdocs-material
    mkdocs-git-revision-date-localized-plugin
cache:
  paths:
    - $PIP_CACHE_DIR
    - $APK_CACHE_DIR

update_mkdocs:
  only: [ schedules ]
  script:
    - apk update
    - apk add --no-cache gcc musl-dev
    - pip install --upgrade $PIP_PACKAGES
    - mkdir -p $APK_CACHE_DIR
    - apk add --cache-dir $APK_CACHE_DIR git

pages:
  only: [ master ]
  except: [ schedules ]
  before_script:
    - apk update --cache-dir $APK_CACHE_DIR
    - apk add --cache-dir $APK_CACHE_DIR git
    - pip install $PIP_PACKAGES
  script:
    - mkdocs build -d public
  artifacts:
    paths:
      - public