Remove keystone_admin-back load balancer manipulation

For multi-node builds, we previously shut down the keystone_admin-back
for the node being worked on when making changes to the keystone node.

This back-end no longer exists, and the second loop does not use loop
control to ensure that the common tasks 'item' and the playbook 'item'
do not clash, causing the task to enable the back-end to have no effect
and keystone remains in maintenance mode.

This patch removes the back-end from the list, and also removes the
port reservation which is no longer applicable.

Change-Id: I0d7e4804bdc92ffe7a679060a686e684c01fcd1b

playbooks/os-keystone-install.yml

@@ -48,14 +48,9 @@
     # the load balancer back end for this container.
     - include: common-tasks/haproxy-endpoint-manage.yml
       vars:
-        haproxy_backend: "{{ backend_name }}"
+        haproxy_backend: "keystone_service-back"
         haproxy_state: disabled
       when: "groups['keystone_all'] | length > 1"
-      loop_control:
-        loop_var: backend_name
-      with_items:
-        - "keystone_service-back"
-        - "keystone_admin-back"
 
     - name: Configure container
       include: "common-tasks/os-{{ container_tech | default('lxc') }}-container-setup.yml"
@@ -77,22 +72,6 @@
       when:
         - hostvars['localhost']['resolvconf_enabled'] | bool
 
-    # todo(cloudnull): this task is being run only if/when keystone is installed on a physical host.
-    #  This is not being run within a container because it is an unsupported action due to this
-    #  issue: (https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1279041)
-    #  This issue was resolved however we'll need to eval it in the next LTS release.
-    #  Related OSA Bug: https://launchpad.net/bugs/1426371
-    - name: Add keystone reserved port to physical host
-      sysctl:
-        name: "{{ item.key }}"
-        value: "{{ item.value }}"
-        sysctl_set: "{{ item.set|default('yes') }}"
-        state: "{{ item.state|default('present') }}"
-        reload: "{{ item.reload|default('yes') }}"
-      with_items:
-        - { key: "net.ipv4.ip_local_reserved_ports", value: "{{ keystone_admin_port }}"}
-      when: is_metal | bool
-
   roles:
     - role: "os_keystone"
     - role: "system_crontab_coordination"
@@ -111,12 +90,9 @@
     # to available again.
     - include: common-tasks/haproxy-endpoint-manage.yml
       vars:
-        haproxy_backend: "{{ item }}"
+        haproxy_backend: "keystone_service-back"
         haproxy_state: enabled
       when: "groups['keystone_all'] | length > 1"
-      with_items:
-        - "keystone_service-back"
-        - "keystone_admin-back"
 
 # These facts are set against the deployment host to ensure that
 # they are fast to access. This is done in preference to setting