Adding swift backend for cinder backup

Prod-Related: PROD-32817
Change-Id: I4ed305f50144947c4b5544d767f1974ad996d4ed
diff --git a/README.rst b/README.rst
index 9abb02c..261f234 100644
--- a/README.rst
+++ b/README.rst
@@ -640,6 +640,60 @@
           ceph_chunk_size: 134217728
           restore_discard_excess_bytes: false
 
+* Enable swift driver for cinder-backup service
+
+  .. code-block:: yaml
+
+   cinder:
+     controller:
+       backup:
+         engine: swift
+         swift:
+           driver: cinder.backup.drivers.swift
+           auth: per_user
+           auth_version: 3
+           block_size: 32768
+           object_size: 52428800
+           container: volumebackup
+           compression_algorithm: gzip
+           retry_attempts: 3
+           retry_backoff: 2
+           catalog_info: object-store:swift:internalURL
+           keystone_catalog_info: identity:Identity Service:publicURL
+           user: test
+           user_domain: localhost
+           key: AAAAAAAAAAA
+           tenant: admin
+           project_domain: localhost
+           project: service
+           enable_progress_timer: True
+           ca_cert_file: /etc/ssl/pki/ca.pem
+
+   cinder:
+     volume:
+       backup:
+         engine: swift
+         swift:
+           driver: cinder.backup.drivers.swift
+           auth: per_user
+           auth_version: 3
+           block_size: 32768
+           object_size: 52428800
+           container: volumebackup
+           compression_algorithm: gzip
+           retry_attempts: 3
+           retry_backoff: 2
+           catalog_info: object-store:swift:internalURL
+           keystone_catalog_info: identity:Identity Service:publicURL
+           user: test
+           user_domain: localhost
+           key: AAAAAAAAAAA
+           tenant: admin
+           project_domain: localhost
+           project: service
+           enable_progress_timer: True
+           ca_cert_file: /etc/ssl/pki/ca.pem
+
 * Auditing filter (CADF) enablement:
 
   .. code-block:: yaml