FFU: Introduce fluentd fast-forward-upgrade tasks

bp fast-forward-upgrades

Change-Id: Icb966f0acf2ba204fe77ae3a394b27fc114d6732

docker/services/fluentd.yaml

@@ -124,4 +124,23 @@ outputs:
         - name: Stop and disable fluentd service
           when: step|int == 2
           service: name=fluentd.service state=stopped enabled=no
-
+      fast_forward_upgrade_tasks:
+        - name: Check if fluent.service is deployed
+          command: systemctl is-enabled --quiet fluentd.service
+          ignore_errors: True
+          register: fluentd_enabled_result
+          when:
+            - step|int == 0
+            - release == 'ocata'
+        - name: Set fact fluentd_enabled
+          set_fact:
+            fluentd_enabled: "{{ fluentd_enabled_result.rc == 0 }}"
+          when:
+            - step|int == 0
+            - release == 'ocata'
+        - name: Stop fluentd service
+          service: name=fluentd.service state=stopped enabled=no
+          when:
+            - step|int == 1
+            - release == 'ocata'
+            - fluentd_enabled|bool