Support to restore backup from remote location

In multi-region deployment with geo-replicated Swift, the user can
restore a backup in one region by manually specifying the original
backup data location created in another region.

Change-Id: Iefef3bf969163af707935445bc23299400dc88c3

3 files changed, 73 insertions, 2 deletions

diff --git a/trove/common/apischema.py b/trove/common/apischema.py
index 4c799992..bc815fad 100644
--- a/trove/common/apischema.py
+++ b/trove/common/apischema.py
@@ -652,14 +652,27 @@ backup = {
         "properties": {
             "backup": {
                 "type": "object",
-                "required": ["instance", "name"],
+                "required": ["name"],
                 "properties": {
                     "description": non_empty_string,
                     "instance": uuid,
                     "name": non_empty_string,
                     "parent_id": uuid,
                     "incremental": boolean_string,
-                    "swift_container": non_empty_string
+                    "swift_container": non_empty_string,
+                    "restore_from": {
+                        "type": "object",
+                        "required": [
+                            "remote_location",
+                            "local_datastore_version_id",
+                            "size"
+                        ],
+                        "properties": {
+                            "remote_location": non_empty_string,
+                            "local_datastore_version_id": uuid,
+                            "size": {"type": "number"}
+                        }
+                    }
                 }
             }
         }
diff --git a/trove/common/constants.py b/trove/common/constants.py
new file mode 100644
index 00000000..0f53477b
--- /dev/null
+++ b/trove/common/constants.py
@@ -0,0 +1,16 @@
+# Copyright 2021 Catalyst Cloud Ltd.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+
+BACKUP_TYPE_FULL = 'full'
+BACKUP_TYPE_INC = 'incremental'
diff --git a/trove/common/swift.py b/trove/common/swift.py
new file mode 100644
index 00000000..43910af1
--- /dev/null
+++ b/trove/common/swift.py
@@ -0,0 +1,42 @@
+# Copyright 2021 Catalyst Cloud Ltd.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+
+
+def parse_location(location):
+    storage_url = "/".join(location.split('/')[:-2])
+    container_name = location.split('/')[-2]
+    object_name = location.split('/')[-1]
+    return storage_url, container_name, object_name
+
+
+def _get_attr(original):
+    """Get a friendly name from an object header key."""
+    key = original.replace('-', '_')
+    key = key.replace('x_object_meta_', '')
+    return key
+
+
+def get_metadata(client, location, extra_attrs=[]):
+    _, container_name, object_name = parse_location(location)
+    headers = client.head_object(container_name, object_name)
+
+    meta = {}
+    for key, value in headers.items():
+        if key.startswith('x-object-meta'):
+            meta[_get_attr(key)] = value
+
+    for key in extra_attrs:
+        meta[key] = headers.get(key)
+
+    return meta