ci: trigger webhook on nightly tests failure (#1727)

Author: Codelax

.github/workflows/nightly.yml

@@ -53,6 +53,26 @@ jobs:
           SCW_SECRET_KEY: ${{ secrets.SCW_SECRET_KEY }}
           SCW_DEFAULT_ORGANIZATION_ID: ${{ secrets.SCW_DEFAULT_ORGANIZATION_ID }}
           SCW_DEFAULT_PROJECT_ID: ${{ secrets.SCW_DEFAULT_PROJECT_ID }}
+      - name: Ping on failure
+        if: ${{ failure() }}
+        run: |
+          curl -X POST -H 'Content-type: application/json' \
+          --data '{
+          	"blocks": [
+              {
+                "type": "section",
+                "text": {
+                    "type": "mrkdwn",
+                    "text": "'"Nightly workflow failed: https://github.com/scaleway/terraform-provider-scaleway/actions/runs/${GITHUB_WORKFLOW_ID}"'"
+                  }
+              }
+            ]
+          }' \
+          ${SLACK_WEBHOOK_NIGHTLY};
+          done
+        env:
+          SLACK_WEBHOOK_NIGHTLY: ${{ secrets.SLACK_WEBHOOK_NIGHTLY }}
+          GITHUB_WORKFLOW_ID: ${{ github.workflow }}
 
   # sweeper needs to run after nightly completed
   # no matter what are the results of the jobs