Add bup backups to ethercalc.openstack.org

This will backup the redis snapshots (among other things) on the
ethercalc server. This should be the last major step before putting this
service into production.

Change-Id: I12d7809f3a0cea560662491ceff1ff7b1e07ce9a

modules/openstack_project/manifests/ethercalc.pp

@@ -19,6 +19,16 @@ class openstack_project::ethercalc (
     ssl_chain_file_contents => $ssl_chain_file_contents,
   }
 
-  # TODO(clarkb) Redis backups
   include ethercalc::redis
+
+  # Redis creates a snapshot at /var/lib/redis/dump.rdb periodically
+  # (at worst every 15 minutes if at least one change is made to redis)
+  # which can be used to recover the Redis DB. Bup will automagically
+  # pick this file up during its normal operation so no other DB dumping
+  # is required like with mysql.
+  include bup
+  bup::site { 'rs-ord':
+    backup_user   => 'bup-etherpad',
+    backup_server => 'ci-backup-rs-ord.openstack.org',
+  }
 }