Derive BACKWARD_INCOMPATIBILITY_IT_ENABLED and DRUID_PREVIOUS_IT_IMAG…

…E_NAME env vars

.github/workflows/unit-and-integration-tests-unified.yml

@@ -47,13 +47,28 @@ concurrency:
 env:
   MYSQL_DRIVER_CLASSNAME: com.mysql.jdbc.Driver # Used to set druid config in docker image for revised ITs
   SEGMENT_DOWNLOAD_TIMEOUT_MINS: 5
-  BACKWARD_INCOMPATIBILITY_IT_ENABLED: true
+  #BACKWARD_INCOMPATIBILITY_IT_ENABLED: true
   DRUID_PREVIOUS_VERSION: 30.0.0
   DRUID_PREVIOUS_VERSION_DOWNLOAD_URL: https://dlcdn.apache.org/druid/30.0.0/apache-druid-30.0.0-bin.tar.gz
-  DRUID_PREVIOUS_IT_IMAGE_NAME: org.apache.druid.integration-tests/test:30.0.0
+  #DRUID_PREVIOUS_IT_IMAGE_NAME: org.apache.druid.integration-tests/test:30.0.0
 
 jobs:
+  set-new-env-var:
+    name: Set new env var
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set new environment variable
+        run: |
+          if [ -n "${{ env.DRUID_PREVIOUS_VERSION }}" ]; then
+            echo "export BACKWARD_INCOMPATIBILITY_IT_ENABLED=true" >> $GITHUB_ENV
+          else
+            echo "export BACKWARD_INCOMPATIBILITY_IT_ENABLED=false" >> $GITHUB_ENV
+          fi
+          echo "export DRUID_PREVIOUS_IT_IMAGE_NAME=org.apache.druid.integration-tests/test:${{ env.DRUID_PREVIOUS_VERSION }}" >> $GITHUB_ENV
+          echo "New environment variable: $DRUID_PREVIOUS_IT_IMAGE_NAME, $BACKWARD_INCOMPATIBILITY_IT_ENABLED"
+
   build:
+    needs: set-new-env-var
     name: "build (jdk${{ matrix.jdk }})"
     strategy:
       fail-fast: false