Change how dockerhub job sets the short-description in update GA work…

…flow

Add support for syncing the short-description with the repository
description through the GitHub API. Also, change existing steps to
validate the number of characters and report using Slack messages.

.github/workflows/update.yml

@@ -24,7 +24,42 @@ jobs:
         if: ${{ github.event_name != 'pull_request' }}
         id: slack
         with:
+          fields: |
+            {STATUS}
+            {REF}
+            Short description length: Checking...
+            Description length: Checking...
           status: in-progress
+      - name: Output additional GitHub context
+        id: github
+        run: |
+          description=$(curl -s -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
+            "https://api.github.com/repos/${{ github.repository }}" | \
+            jq -r '.description')
+          echo "description=$description" >> $GITHUB_OUTPUT
+      - name: Output lengths
+        id: lengths
+        run: |
+          description=$(cat ./DOCKERHUB.md | wc -c)
+          short_description=$(echo '${{ steps.github.outputs.description }}' | wc -c)
+
+          echo "description=$description" >> $GITHUB_OUTPUT
+          echo "short-description=$short_description" >> $GITHUB_OUTPUT
+      - name: Check results
+        run: |
+          description_length='${{ steps.lengths.outputs.description }}'
+          short_description='${{ steps.github.outputs.description }}'
+          short_description_length='${{ steps.lengths.outputs.short-description }}'
+
+          echo "Short description: $short_description"
+          echo "Short description length: $short_description_length"
+          echo "Description length: $description_length"
+
+          exit_code=1
+          if [ "$description_length" -gt 0 ] && [ "$description_length" -lt 25000 ] && [ "$short_description_length" -gt 0 ]; then
+            exit_code=0
+          fi
+          exit "$exit_code"
       - name: Update Docker Hub repository overview
         uses: peter-evans/dockerhub-description@v3
         if: ${{ !env.ACT }}
@@ -38,5 +73,10 @@ jobs:
         uses: codedsolar/slack-action@v1
         if: ${{ github.event_name != 'pull_request' && always() }}
         with:
+          fields: |
+            {STATUS}
+            {REF}
+            Short description length: ${{ steps.lengths.outputs.short-description || 'Skipped' }}
+            Description length: ${{ steps.lengths.outputs.description || 'Skipped' }}
           status: ${{ job.status }}
           timestamp: ${{ steps.slack.outputs.slack-timestamp }}