check_links.yaml

# Check links on the 21st day of the month.
# 21st as the first letter of this repo is the 21st letter in the alphabet.
on:
  push:
  pull_request:
  schedule:
  - cron: "0 0 21 * *"

name: check links

jobs:
  check-links:
    runs-on: ubuntu-latest
    env:
      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - uses: actions/checkout@v2

      # The link checker will only work if mlc_config.json is a valid JSON
      - name: Validate JSON
        uses: docker://orrosenblatt/validate-json-action:latest
        env:
          INPUT_SCHEMA: .github/workflows/valid_json_schema.json
          INPUT_JSONS: mlc_config.json

      # These are status code that cannot be ignored.
      #
      # If there is a valid external link that fails,
      # add it to mlc_config.json
      - name: External links must be checked, do not allow '0' in the 'aliveStatusCodes' of mlc_config.json
        run: if [[ $(grep --regexp "[^0-9]0[^0-9]" mlc_config.json | wc --lines) == "1" ]]; then echo "FOUND"; exit 42; fi

      - name: Internal links must checked, do not allow '400' in the 'aliveStatusCodes' of mlc_config.json
        run: if [[ $(grep --regexp "[^0-9]400[^0-9]" mlc_config.json | wc --lines) == "1" ]]; then echo "FOUND"; exit 42; fi

      - uses: gaurav-nelson/github-action-markdown-link-check@v1
        with:
          config-file: 'mlc_config.json'
          use-quiet-mode: 'yes'
          use-verbose-mode: 'no'