Make backup/restore file name a parameter [(#2248)](GoogleCloudPlatform/python-docs-samples#2248)

* Make backup/restore file a parameter

Previously was hard coded as 'backup.json'

* Added parameter to test function calls

Author: engelke

samples/snippets/v3/alerts-client/snippets.py

@@ -108,15 +108,17 @@ def delete_notification_channels(project_name, channel_ids, force=None):
 
 
 # [START monitoring_alert_backup_policies]
-def backup(project_name):
+def backup(project_name, backup_filename):
     alert_client = monitoring_v3.AlertPolicyServiceClient()
     channel_client = monitoring_v3.NotificationChannelServiceClient()
     record = {'project_name': project_name,
               'policies': list(alert_client.list_alert_policies(project_name)),
               'channels': list(channel_client.list_notification_channels(
                   project_name))}
-    json.dump(record, open('backup.json', 'wt'), cls=ProtoEncoder, indent=2)
-    print('Backed up alert policies and notification channels to backup.json.')
+    json.dump(record, open(backup_filename, 'wt'), cls=ProtoEncoder, indent=2)
+    print('Backed up alert policies and notification channels to {}.'.format(
+        backup_filename)
+    )
 
 
 class ProtoEncoder(json.JSONEncoder):
@@ -136,9 +138,11 @@ def default(self, obj):
 # [START monitoring_alert_create_channel]
 # [START monitoring_alert_update_channel]
 # [START monitoring_alert_enable_channel]
-def restore(project_name):
-    print('Loading alert policies and notification channels from backup.json.')
-    record = json.load(open('backup.json', 'rt'))
+def restore(project_name, backup_filename):
+    print('Loading alert policies and notification channels from {}.'.format(
+        backup_filename)
+    )
+    record = json.load(open(backup_filename, 'rt'))
     is_same_project = project_name == record['project_name']
     # Convert dicts to AlertPolicies.
     policies_json = [json.dumps(policy) for policy in record['policies']]
@@ -299,11 +303,19 @@ def project_name():
         'backup',
         help=backup.__doc__
     )
+    backup_parser.add_argument(
+        '--backup_to_filename',
+        required=True
+    )
 
     restore_parser = subparsers.add_parser(
         'restore',
         help=restore.__doc__
     )
+    restore_parser.add_argument(
+        '--restore_from_filename',
+        required=True
+    )
 
     args = parser.parse_args()
 
@@ -325,7 +337,7 @@ def project_name():
                                       args.notification_channel_id)
 
     elif args.command == 'backup':
-        backup(project_name())
+        backup(project_name(), args.backup_to_filename)
 
     elif args.command == 'restore':
-        restore(project_name())
+        restore(project_name(), args.restore_from_filename)

samples/snippets/v3/alerts-client/snippets_test.py

@@ -107,10 +107,10 @@ def test_replace_channels(capsys, pochan):
 
 
 def test_backup_and_restore(capsys, pochan):
-    snippets.backup(pochan.project_name)
+    snippets.backup(pochan.project_name, 'backup.json')
     out, _ = capsys.readouterr()
 
-    snippets.restore(pochan.project_name)
+    snippets.restore(pochan.project_name, 'backup.json')
     out, _ = capsys.readouterr()
     assert "Updated {0}".format(pochan.alert_policy.name) in out
     assert "Updating channel {0}".format(