Django management command: applybackup

README.md

@@ -58,6 +58,18 @@ Note: Using the localhost IP address as above will route to the default app (cur
 
 Note: if the specification for the VM changes, e.g. what's in the `Vagrantfile`, those changes will need to be retrospectively applied to any existing machines. Either `vagrant reload --provision` the existing machine, or `vagrant destroy; vagrant up` to create a fresh machine to this spec.
 
+#### Backup, and restoring from it
+
+A production install should automatically backup the database and key files to a cloud service.
+
+A django management command is included to apply this backup to a local machine, i.e. follow the above procedure with this.
+
+```
+vagrant up
+vagrant ssh
+python3.6 /folk_rnn_webapp/folk_rnn_site/manage.py apply_backup
+```
+
 #### Tests
 ```
 vagrant up

folk_rnn_site/backup/management/commands/applybackup.py

@@ -0,0 +1,45 @@
+import os
+import tarfile
+import logging
+from tempfile import TemporaryDirectory
+
+from django.core.management.base import BaseCommand
+from django.core.management import call_command
+
+from .backup import Command as BackupCommand
+
+logger = logging.getLogger(__name__)
+
+class Command(BaseCommand):
+    """"
+    Download the latest production backup and apply to local machine
+    """
+    help = 'Download the latest production backup and apply to local machine'
+
+    def handle(self, *args, **kwargs):
+        '''
+        Process the command (i.e. the django manage.py entrypoint)
+        '''
+        logger.info('Apply Backup starting.')
+
+        backup = BackupCommand()
+
+        with TemporaryDirectory() as tmp:
+            logger.info('Downloading latest production backup...')
+            db_path, log_path, tunes_path = backup.download_latest_production_backup(to_dir=tmp)
+
+            logger.info('Applying database...')
+            with tarfile.open(name=db_path, mode='r:bz2') as tar:
+                tar.extractall(path=tmp)
+                call_command('flush', interactive=False) # Ideally drop, create and migrate
+                call_command('loaddata', os.path.join(tmp, 'db_data.json'))
+
+            logger.info('Applying logs...')
+            with tarfile.open(name=log_path, mode='r:bz2') as tar:
+                tar.extractall(path='/')
+
+            logger.info('Applying tune...')
+            with tarfile.open(name=tunes_path, mode='r:bz2') as tar:
+                tar.extractall(path='/')
+
+        logger.info('Apply Backup finished.')

folk_rnn_site/backup/management/commands/backup.py

@@ -217,7 +217,9 @@ def download_latest_production_backup(self, to_dir=''):
                 for name in names:
                     download_path = os.path.join(to_dir, name[2])
                     self.download_file(name[1], download_path)
+                    name.append(download_path)
                 break
+        return ([x[3] for x in names])
 
     def delete_file(self, file_id):
         """