Make BIND /var dir persistent

BIND stores dynamically created zones in /var/named by default,
which means that this directory needs to be persistent across
container restarts.  However, we can't just bind mount /var/named
into the container because /var/named is empty on the host, but in
the container the BIND package populates some necessary initial files
in it.

To address this, we can point BIND at /var/named-persistent and
copy all of the initial config from /var/named at container start,
just like we do for other configs.

Change-Id: Ic17fb812468f2eb66d9c348b51dfa73a1f216a70

docker/services/designate-worker.yaml

@@ -113,11 +113,15 @@ outputs:
               dest: "/"
               merge: true
               preserve_properties: true
+            - source: "/var/named/*"
+              dest: "/var/named-persistent/"
+              merge: true
+              preserve_properties: true
           permissions:
             - path: /var/log/designate
               owner: designate:designate
               recurse: true
-            - path: /var/named
+            - path: /var/named-persistent
               owner: root:named
               perm: '0770'
       docker_config:
@@ -152,6 +156,7 @@ outputs:
                   - /var/lib/kolla/config_files/designate_backend_bind9.json:/var/lib/kolla/config_files/config.json:ro
                   - /var/lib/config-data/puppet-generated/designate/:/var/lib/kolla/config_files/src:ro
                   - /var/log/containers/designate:/var/log/designate
+                  - /var/named-persistent:/var/named-persistent
             environment:
               - KOLLA_CONFIG_STRATEGY=COPY_ALWAYS
       host_prep_tasks:
@@ -166,3 +171,7 @@ outputs:
               Log files from designate containers can be found under
               /var/log/containers/designate.
           ignore_errors: true
+        - name: create persistent named directory
+          file:
+            path: /var/named-persistent
+            state: directory

puppet/services/designate-worker.yaml

@@ -69,6 +69,7 @@ outputs:
         map_merge:
         - get_attr: [DesignateBase, role_data, config_settings]
         - designate::worker::worker_notify: true
+          dns::vardir: /var/named-persistent
           dns::additional_options:
             listen-on:
               str_replace: