Enabled memcached usage for token caching

As of today blazar warns out on startup that using the in-process token
cache is deprecated for quite a while. In order to get rid of this warning
we add memcached configuration for keystone token.

Change-Id: Ibd80231bdb1dfe2e66e69c4538a2129c7f84c92f

defaults/main.yml

@@ -50,6 +50,8 @@ blazar_manager_plugins:
   - virtual.instance.plugin
   - virtual.floatingip.plugin
 
+blazar_memcached_servers: "{{ memcached_servers }}"
+
 ## Common PIP requirements
 blazar_pip_packages:
   - "git+{{ blazar_git_repo }}@{{ blazar_git_install_branch }}#egg=blazar"
@@ -58,6 +60,8 @@ blazar_pip_packages:
   - pymysql
   - python-blazarclient
   - systemd-python
+  - pymemcache
+  - python-memcached
 
 ## blazar constraints
 blazar_git_constraints:

releasenotes/notes/blazar_memcached-b069ef6d7dfcbe76.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Blazar now using memcached for token caching. List of memcached servers
+    can be controlled using ``blazar_memcached_servers`` variable.

templates/blazar.conf.j2

@@ -49,6 +49,10 @@ service_token_roles_required = {{ blazar_service_token_roles_required | bool }}
 service_token_roles = {{ blazar_service_token_roles | join(',') }}
 service_type = {{ blazar_service_type }}
 
+memcached_servers = {{ blazar_memcached_servers }}
+memcache_security_strategy = ENCRYPT
+memcache_secret_key = {{ memcached_encryption_key }}
+
 [database]
 connection = mysql+pymysql://{{ blazar_galera_user }}:{{ blazar_container_mysql_password }}@{{ blazar_galera_address }}:{{ blazar_galera_port }}/{{ blazar_galera_database }}?charset=utf8{% if blazar_galera_use_ssl | bool %}&ssl_verify_cert=true{% if blazar_galera_ssl_ca_cert | length > 0 %}&ssl_ca={{ blazar_galera_ssl_ca_cert }}{% endif %}{% endif +%}
 max_overflow = {{ blazar_db_max_overflow }}