CI: Add Slack alert to automatically triggered workflows

Alert on failures for automatically triggered workflows. For manually
triggered workflows we rely on GitHub emails to the individual that
triggered the workflow.

See the "Workflow builder" approach in
https://github.com/slackapi/slack-github-action/.

.github/workflows/stackhpc-build-kayobe-image.yml

@@ -98,3 +98,25 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+
+      - name: Send message to Slack via Workflow Builder
+        uses: slackapi/[email protected]
+        with:
+          payload: |
+            {
+              "channel-id": "${{ env.SLACK_CHANNEL_ID }}",
+              "inputs": "${{ env.INPUTS }}",
+              "message": "${{ env.MESSAGE }}",
+              "results-url": "${{ env.RESULTS_URL }}",
+              "workflow-url": "${{ env.WORKFLOW_URL }}"
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+          # #release-train-alerts
+          SLACK_CHANNEL_ID: C03B28HRP53
+          INPUTS: >-
+            branch: ${{ github.ref_name }}
+          MESSAGE: "SKC Build Kayobe Image workflow failed :sob:"
+          RESULTS_URL: "N/A"
+          WORKFLOW_URL: "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+        if: failure() && github.event_name == 'push'

.github/workflows/stackhpc-ci-cleanup.yml

@@ -75,3 +75,24 @@ jobs:
           OS_CLOUD: openstack
           OS_APPLICATION_CREDENTIAL_ID: ${{ secrets.OS_APPLICATION_CREDENTIAL_ID }}
           OS_APPLICATION_CREDENTIAL_SECRET: ${{ secrets.OS_APPLICATION_CREDENTIAL_SECRET }}
+
+      - name: Send message to Slack via Workflow Builder
+        uses: slackapi/[email protected]
+        with:
+          payload: |
+            {
+              "channel-id": "${{ env.SLACK_CHANNEL_ID }}",
+              "inputs": "${{ env.INPUTS }}",
+              "message": "${{ env.MESSAGE }}",
+              "results-url": "${{ env.RESULTS_URL }}",
+              "workflow-url": "${{ env.WORKFLOW_URL }}"
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+          # #release-train-alerts
+          SLACK_CHANNEL_ID: C03B28HRP53
+          INPUTS: "N/A"
+          MESSAGE: "SKC CI Cleanup workflow failed :sob:"
+          RESULTS_URL: "N/A"
+          WORKFLOW_URL: "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+        if: failure()

.github/workflows/stackhpc-promote.yml

@@ -27,3 +27,25 @@ jobs:
       - name: Display link to package repository promotion workflows
         run: |
           echo "::notice Package repository promote workflow: https://github.com/stackhpc/stackhpc-release-train/actions/workflows/package-promote.yml"
+
+      - name: Send message to Slack via Workflow Builder
+        uses: slackapi/[email protected]
+        with:
+          payload: |
+            {
+              "channel-id": "${{ env.SLACK_CHANNEL_ID }}",
+              "inputs": "${{ env.INPUTS }}",
+              "message": "${{ env.MESSAGE }}",
+              "results-url": "${{ env.RESULTS_URL }}",
+              "workflow-url": "${{ env.WORKFLOW_URL }}"
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+          # #release-train-alerts
+          SLACK_CHANNEL_ID: C03B28HRP53
+          INPUTS: >-
+            branch: ${{ github.ref_name }}
+          MESSAGE: "SKC promote workflow failed :sob:"
+          RESULTS_URL: "N/A"
+          WORKFLOW_URL: "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+        if: failure()