Use slurp to collect the keystone ssh keys

Extracting the ssh public key using cat and storing the result in a
fact has resulted in periodic failures in the collection of the key,
and thereafter the failure to appropriately place that key into the
authorised_keys file.

This patch changes the collection method to use the Ansible slurp
module which has been found to be more reliable.

Change-Id: Iac61518129536ce613e91ac894883440a8704998

tasks/keystone_key_distribute.yml

@@ -16,7 +16,7 @@
 - name: Create authorized keys file from host vars
   authorized_key:
     user: "{{ keystone_system_user_name }}"
-    key: "{{ hostvars[item]['keystone_pubkey'] }}"
+    key: "{{ hostvars[item]['keystone_pubkey'] | b64decode }}"
   with_items: groups['keystone_all']
   tags:
     - keystone-key

tasks/keystone_key_populate.yml

@@ -14,8 +14,8 @@
 # limitations under the License.
 
 - name: Get public key contents and store as var
-  command: |
-    cat {{ keystone_system_user_home }}/.ssh/id_rsa.pub
+  slurp:
+    src: "{{ keystone_system_user_home }}/.ssh/id_rsa.pub"
   register: keystone_pub
   changed_when: false
   tags:
@@ -24,7 +24,7 @@
 
 - name: Register a fact for the keystone pub key
   set_fact:
-     keystone_pubkey: "{{ keystone_pub.stdout }}"
+     keystone_pubkey: "{{ keystone_pub.content }}"
   tags:
     - keystone-key
     - keystone-key-create