Restoring whole yunohost from borg backups

Discuss Tutorials
5

For the record, this is a complete description of the process I followed:

Restore a complete system from borg backups

For infos on restoring process, check this yunohost forum thread and that one, also using borg with sshkeys, the borg extract documentation, and this general tutorial on borg backup.

In the following explanations:

  • the server to backup/restore will be called: yuno
  • the remote server that receives and store the back will be called: rem
  • rem is accessible at the domain rem.tld
  • the remote user on rem which owns the borg backups will be called yurem
  • backup files will be stored in rem in the directory: /home/yurem/backup

Overview

The idea here, if you need to restore a whole yunohost system is:

  1. Install a new debian VM
  2. Install yunohost in it the usual way
  3. Go through yunohost postinstall (parameters you will supply are not crucial, as they will be replaced by the restore)
  4. Install borg
  5. Setup rem to accept ssh connections from yuno
  6. Use borg to import backups from rem to yuno
  7. Restore borg backups with the yunohost backup restore command, first config, then data, then each app one at a time
  8. Remove the borg app and restore it

Make it possible for yuno to connect to rem with borg

At this stage, we will assume that yuno is a freshly installed yunohost (based on buster in my case). You should also have performed the yunohost postinstall.

If you don’t want to restore the whole system, just some apps, you can skip some of the steps below.

Install the borg yunohost app in yuno

The idea here is just to install borg, not in order to create backups, but only to use borg commands to import remote backups.

So for example, you can install it doing the following:

sudo yunohost app install borg -a "server=rem.tld&ssh_user=yurem&conf=0&data=0&apps=hextris&on_calendar=2:30"

Make sure that rem accepts ssh connections from yuno

In yuno you will need to get the ssh key that borg just created while installing: sudo cat /root/.ssh/id_borg_ed25519.pub, copy it to clipboard.

Connect via ssh to rem, go to /home/yurem/.ssh/authorized_keys, and past the borg public key you got at previous step.

Now to make sure this worked, you can try to ssh from yuno to rem.
In yuno : ssh -i /root/.ssh/id_borg_ed25519 yurem@rem.tld . If you can get into rem , without it prompting for a password, then you’re good to continue :slight_smile:

Restore backups to yuno

:warning: For the commands in the following section to work, you will need to be root in yuno (you can become root running sudo su).

:warning: Restoration of backups can take quite a while, you’d better do them in a separate process, so that it doesn’t stop if your terminal session gets closed. For this, you can for example use tmux.

In yuno now, you should be able to list backups in rem with the following command:

SRV=yurem@rem.tld:/home/yurem/backup
BORG_RSH="ssh -i /root/.ssh/id_borg_ed25519 -oStrictHostKeyChecking=yes " borg list $SRV

You can then reimport one to yuno with:

BORG_RSH="ssh -i /root/.ssh/id_borg_ed25519 -oStrictHostKeyChecking=yes " borg export-tar $SRV::auto_BACKUP_NAME /home/yunohost.backup/archives/auto_BACKUP_NAME.tar.gz

And then restore the archive in yuno with:

yunohost backup restore auto_BACKUP_NAME --system # for config and data backups
yunohost backup restore auto_BACKUP_NAME --apps # for other backups (=apps)

And nextcloud? It’s super heavy!!

For nextcloud, the best is probably to reimport the backup without the data. And to import the data manually.

For that, you can do the following (as root):

SRV=yurem@rem.tld:/home/yurem/backup

# export the app without data
BORG_RSH="ssh -i /root/.ssh/id_borg_ed25519 -oStrictHostKeyChecking=yes " borg export-tar -e apps/nextcloud/backup/home/yunohost.app $SRV::auto_nextcloud_XX_XX_XX_XX:XX /home/yunohost.backup/archives/auto_nextcloud_XX_XX_XX_XX:XX.tar.gz

# extract the data from the backup to the nextcloud folder
cd /home/yunohost.app/nextcloud
BORG_RSH="ssh -i /root/.ssh/id_borg_ed25519 -oStrictHostKeyChecking=yes " borg extract $SRV::auto_nextcloud_XX_XX_XX_XX:XX apps/nextcloud/backup/home/yunohost.app/nextcloud/
mv apps/nextcloud/backup/home/yunohost.app/nextcloud/data data
rm -r apps

# now you can simply restore nextcloud app
yunohost backup restore auto_nextcloud_XX_XX_XX_XX:XX --apps

Restore borg

Once you’ve restored the whole system, you will probably want to restore the borg app as well.

For that, remove the “dummy” borg you installed to do the restoration, and restore borg the same ways as for other apps:

sudo yunohost app remove borg
sudo yunohost backup restore auto_borg_XX_XX_XX_XX:XX --apps
3 Likes