ffu: Introduce Keystone fast-forward upgrade tasks

fast_forward_upgrade_tasks for keystone covering Ocata and Pike.
- Service status check
- Stop service when updating from Ocata to Pike
- Update keystone package
- Db sync

bp fast-forward-upgrades
Change-Id: I65b0c562c6e2545e99e9511d7b148c2130cc6b25

docker/services/keystone.yaml

@@ -227,3 +227,40 @@ outputs:
             state: absent
       metadata_settings:
         get_attr: [KeystoneBase, role_data, metadata_settings]
+      fast_forward_upgrade_tasks:
+        - name: Check for keystone running under apache
+          tags: common
+          shell: "httpd -t -D DUMP_VHOSTS | grep -q keystone_wsgi"
+          ignore_errors: true
+          register: httpd_enabled
+        - name: Check if httpd is running
+          ignore_errors: True
+          register: httpd_running
+          command: systemctl is-active --quiet httpd
+        - name: Stop and disable keystone (under httpd)
+          service: name=httpd state=stopped enabled=no
+          when:
+            - step|int == 2
+            - release == 'ocata'
+            - httpd_enabled.rc == 0
+            - httpd_running.rc == 0
+        - name: Keystone package update
+          yum:
+            name: '{{ package }}'
+            state: latest
+          when:
+            - step|int == 6
+            - is_bootstrap_node|bool
+          loop_control:
+            loop_var: package
+          with_items:
+            - openstack-keystone
+            - python2-keystoneclient
+            - python-keystone
+            - python2-keystonemiddleware
+            - python2-keystoneauth1
+        - name: keystone db sync
+          command: keystone-manage db_sync
+          when:
+            - step|int == 8
+            - is_bootstrap_node|bool