glance: disable swift backend

- Disable Swift backend in the list of stores available in Glance.
- Set file backend by default.
- include glance::backend::file

We're having a lot of OOM in swift-proxy-server at this time, this patch
aims to temporarily disable Swift backend for Glance.

We'll reconsider enable it again in the future, but due to limited CI
resources, let's disable it now.

Related-Bug: #1595916
Change-Id: I5e2feff7e5dc900849c9535f2b7ac05d3c8f93e1

elements/puppet-stack-config/puppet-stack-config.pp

@@ -264,7 +264,7 @@ if $step == 2 {
   # TODO: notifications, scrubber, etc.
   include ::glance::api
   include ::glance::registry
-  include ::glance::backend::swift
+  include ::glance::backend::file
   include ::glance::notify::rabbitmq
 
   class { '::nova':

elements/puppet-stack-config/puppet-stack-config.yaml.template

@@ -71,9 +71,10 @@ glance::api::identity_uri: "%{hiera('keystone_identity_uri')}"
 glance::api::registry_host: {{LOCAL_IP}}
 glance::api::keystone_password: {{UNDERCLOUD_GLANCE_PASSWORD}}
 glance::api::stores:
-  - glance.store.filesystem.Store
-  - glance.store.swift.Store
-glance::api::default_store: 'glance.store.swift.Store'
+  - file
+# For now, we can't enable Swift backend because of OOM issue.
+# See https://bugs.launchpad.net/tripleo/+bug/1595916
+glance::api::default_store: 'file'
 glance::api::pipeline: 'keystone'
 # used to construct glance_api_servers
 glance_port: 9292