Alpha builds workflow: pass on more input parameters

Author: michaelklishin

.github/workflows/alpha-build.yaml

@@ -7,18 +7,34 @@ on:
     paths:
       - "deps/**"
       - ".github/workflows/**"
+env:
+  DEV_WORKFLOW_REPOSITORY: "rabbitmq/server-packages"
 jobs:
   trigger_alpha_build:
     runs-on: ubuntu-latest
     steps:
       - name: Compute prerelease identifier from commit SHA
         run: echo "PRERELEASE_IDENTIFIER=`echo ${{ github.sha }} | cut -c1-8`" >> $GITHUB_ENV
-      - name: Trigger an alpha build in rabbitmq/server-packages
+      - name: Compute event date and time
+        run: echo "PRERELEASE_TIMESTAMP=`date --rfc-3339=seconds`" >> $GITHUB_ENV
+      - name: Compute event UNIX timestamp
+        run: echo "PRERELEASE_TIMESTAMP=`date +%s`" >> $GITHUB_ENV
+      - name: Trigger an alpha build in ${{ env.DEV_WORKFLOW_REPOSITORY }}
         run: |
           curl -L \
             -X POST \
             -H "Accept: application/vnd.github+json" \
             -H "Authorization: Bearer ${{ secrets.RABBITMQCI_BOT_TOKEN }}" \
             -H "X-GitHub-Api-Version: 2022-11-28" \
-            https://api.github.com/repos/rabbitmq/server-packages/dispatches \
-            -d '{"event_type": "new_4.1.x_alpha", "client_payload": {"prerelease": true, "prerelease_kind": "alpha", "prerelease_identifier": "${{ env.PRERELEASE_IDENTIFIER }}", "base_version": "4.1.0"}}'
+            https://api.github.com/repos/rabbitmq/${{ env.DEV_WORKFLOW_REPOSITORY }}/dispatches \
+            -d '{ \
+           "event_type": "new_4.1.x_alpha", \
+           "client_payload": { \
+              "release_repository": "rabbitmq/${{ env.DEV_WORKFLOW_REPOSITORY }}", \
+              "release_description": "Built from https://github.com/rabbitmq/rabbitmq-server/commit/${{ github.sha }} at ${{ env.PRERELEASE_TIMESTAMP }}", \
+              "prerelease": true, \
+              "prerelease_kind": "alpha",\
+              "prerelease_identifier": "${{ env.PRERELEASE_IDENTIFIER }}",\
+              "prerelease_title": "RabbitMQ alpha build, timestamp: ${{ env.PRERELEASE_TIMESTAMP }}, version: 4.1.0-alpha.${{ env.PRERELEASE_IDENTIFIER }}",\
+              "base_version": "4.1.0"
+            }}'