Write out db config for root user

We use this in some utlity scripts, but we currently don't
write it out anywhere. It was an old puppet artifact.

Change-Id: Ib6fdfc4f4a9c5d1befdb6d256989450996dd2a3d

playbooks/roles/gerrit/tasks/main.yaml

@@ -290,6 +290,13 @@
 - name: Start gerrit
   include_tasks: start.yaml
 
+- name: Set up root mysql conf file
+  when: gerrit_database_type == 'MYSQL'
+  template:
+    src: root.my.cnf.j2
+    dest: /root/.gerrit_db.cnf
+    mode: 0400
+
 - name: Set up cron job to optmize git repos
   cron:
     name: optmize-git-repos

playbooks/roles/gerrit/templates/root.my.cnf.j2

@@ -0,0 +1,5 @@
+[client]
+host={{ gerrit_mysql_host }}
+user=gerrit2
+password={{ gerrit_mysql_password }}
+ssl=false