Address Ansible bare variable usage

When executing the bootstrap-host role with Ansible 2.1, the following
deprecation warning is issued in the output for some tasks.

[DEPRECATION WARNING]: Using bare variables is deprecated.

This patch addresses the tasks to fix the behaviour appropriately.

Change-Id: I5e5dba540256935ffb03ace27c6c43abc15f52da

tasks/ceph_auth.yml

@@ -68,8 +68,8 @@
     # If I'm correct, the use case for multiple users is on the computre nodes,
     # access needed by users libvirt-qemu and nova
     mode:     0640
-  with_items:   ceph_client_keyrings.results
-  when: not item|skipped and inventory_hostname in groups[item.item.0.component]
+  with_items: "{{ ceph_client_keyrings.results }}"
+  when: not item | skipped and inventory_hostname in groups[item.item.0.component]
   notify:
   - Restart os services
   tags:

tasks/ceph_get_mon_host.yml

@@ -20,7 +20,7 @@
   # failed_when: false  is needed to not loose any hosts, as this check expects
   # some to be down.
   local_action:   command nc -w 1 {{ item }} 22
-  with_items:     '{{ ceph_mons }}'
+  with_items:     "{{ ceph_mons }}"
   changed_when:   false
   failed_when:    false
   register:       ceph_mon_upcheck
@@ -33,7 +33,7 @@
   set_fact:
                   ceph_mon_host: '{{ item.item }}'
   when:           item.rc == 0 and "OpenSSH" in item.stdout
-  with_items:     ceph_mon_upcheck.results
+  with_items:     "{{ ceph_mon_upcheck.results }}"
   tags:
   - ceph-config-create-config
   - ceph-auth-client-keyrings

tasks/ceph_preinstall_apt.yml

@@ -18,7 +18,7 @@
     id: "{{ item }}"
     state: "absent"
   register: revoke_keys
-  with_items: ceph_revoked_gpg_keys
+  with_items: "{{ ceph_revoked_gpg_keys }}"
   when: ceph_pkg_source == 'ceph'
   tags:
     - ceph-apt-keys
@@ -35,7 +35,7 @@
   ignore_errors: True
   retries: 5
   delay: 2
-  with_items: ceph_gpg_keys
+  with_items: "{{ ceph_gpg_keys }}"
   when: ceph_pkg_source == 'ceph'
   tags:
     - ceph-apt-keys
@@ -50,7 +50,7 @@
   until: add_keys_fallback|success
   retries: 5
   delay: 2
-  with_items: ceph_gpg_keys
+  with_items: "{{ ceph_gpg_keys }}"
   when: ceph_pkg_source == 'ceph' and
         add_keys|failed and
         (item.fallback_keyserver is defined or