.github/workflows/link-schedule.yaml

name: Check links daily

on:
  workflow_dispatch:
  schedule:
    - cron: "18 0 * * *"

permissions:
  issues: write # to create an issue when link check fails

env:
  OUTPUT_FILE: lychee.md

jobs:
  build-and-check-links:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@main
      - name: Install lychee
        env:
          LYCHEEVERSION: 0.13.0
        # due to the limitation of Apache, we can't use lycheeverse/lychee-action directly,
        # so we re-use some core code from it
        run: |
          curl -sLO "https://github.com/lycheeverse/lychee/releases/download/v${{ env.LYCHEEVERSION }}/lychee-v${{ env.LYCHEEVERSION }}-x86_64-unknown-linux-gnu.tar.gz"
          tar -xvzf "lychee-v${{ env.LYCHEEVERSION }}-x86_64-unknown-linux-gnu.tar.gz"
          rm "lychee-v${{ env.LYCHEEVERSION }}-x86_64-unknown-linux-gnu.tar.gz"
          install -t "$HOME/.local/bin" -D lychee 
          rm lychee
          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
      - name: Link Checker
        env:
          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}          
          # For parameter description, see https://github.com/lycheeverse/lychee#commandline-parameters
          # -E, --exclude-all-private    Exclude all private IPs from checking.
          # -i, --insecure               Proceed for server connections considered insecure (invalid TLS)
          # -n, --no-progress            Do not show progress bar.
          # -t, --timeout <timeout>      Website timeout in seconds from connect to response finished [default:20]
          # --max-concurrency <max-concurrency>    Maximum number of concurrent network requests [default: 128]
          # -a --accept <accept>                      Comma-separated list of accepted status codes for valid links
          # -m, --max-redirects <MAX_REDIRECTS>

          # 'build': the site directory to check
          # './*.md': all markdown files in the root directory
        run: |
          # run lychee
          GITHUB_WORKFLOW_URL="https://github.com/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}?check_suite_focus=true"

          if ! lychee --output ${OUTPUT_FILE} \
            -E -i -n -t 5 --max-concurrency 64 -a 429,401,403 -m 10 -f markdown -s http -s https -X HEAD \
            '**/*.md'
          then
            echo "" >> "${OUTPUT_FILE}" # add a new line
            echo "[Full Github Actions output](${GITHUB_WORKFLOW_URL})" >> "${OUTPUT_FILE}"
            gh issue list -S "is:open Broken links found in the website"
            if ! gh issue list -S "is:open Broken links found in the website" | grep -F "Broken links found in the website"; then
              gh issue create --title "Broken links found in the website" --body-file "${OUTPUT_FILE}" --repo "${GITHUB_REPOSITORY}" --assignee "${GITHUB_ACTOR}" --label "type/bug"
            else
              echo "Broken links found in the website, but an issue already exists."
            fi
            exit 1
          fi