Edit Trivy workflow

.github/workflows/trivy.yaml

@@ -1,6 +1,7 @@
 name: dsp-appsec-trivy
 on: [pull_request]
-
+  schedule:
+    - cron: '0 0 * * 0'
 jobs:
   appsec-trivy:
     # Parse Dockerfile and build, scan image if a "blessed" base image is not used
@@ -14,4 +15,14 @@ jobs:
       - uses: broadinstitute/dsp-appsec-trivy-action@v1
         with:
              context: ./orchestration
-             dockerfile: Dockerfile
+             dockerfile: Dockerfile
+    name: Alert on failures
+    if: ${{failure()}}
+    id: slack
+    uses: slackapi/[email protected]
+    with:
+      channel-id: '${{ secrets.CHANNEL_ID }}'
+      # For posting a simple plain text message
+      slack-message: "Trivy weekly job failed! <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|Click here> to see the run. "
+    env:
+      SLACK_BOT_TOKEN: ${{ secrets.SLACK_KEY }}