Backup and restore


UBOS backup files

To make backup and restore easy, UBOS uses standard ZIP files, with certain additional conventions. To distinguish them from arbitrary other ZIP files, UBOS backup files typically use the extension .ubos-backup.

With a single command, you can backup all the data of all the Apps installed on your Device to a single UBOS backup file. Or, you can use separate backup files for each Site on your Devices. You can also back up just a single App at a Site to a backup file.

Similarly, given a .ubos-backup file, you can restore an entire Site (same hostname, same TLS credentials, same Apps with all of their data at the same context paths) or or only parts. You can also change hostnames and context paths during restore.

UBOS keeps track inside the backup file what Apps you backed up, and how they were configured at the time they were backed up. This makes UBOS backup files essentially self-documenting, and makes it possible that backups can be interpreted even at some considerable time in the future: all information required to restore an App to the state is was in at the time the backup was created is contained in the UBOS backup file.

The details of the UBOS backup format are documented for developers.

Creating a local backup

To create a local backup of all the data of all the Apps on the Device and save that data to file <backupfile>, execute:

% sudo ubos-admin backup --tobackupfile <backupfile>

If you like UBOS to pick a suitable filename that includes the current date, only specify the directory:

% sudo ubos-admin backup --tobackupdir ~

This will create a backup file containing all installed Apps at all Sites on the local host.

If you run more than one Site on a Device, to create a local backup of all the data of only the Apps and Accessories of one particular Site with SiteId <siteid>, and to save that backup to file <backupfile>, execute:

% sudo ubos-admin backup --siteid <siteid> --tobackupfile <backupfile>

To determine the correct <siteid>, use ubos-admin listsites --detail.

Alternatively, you can specify the hostname of the Site:

% sudo ubos-admin backup --hostname <hostname> --tobackupfile <backupfile>

If you run more than one App at a Site, to create a local backup of all the data of only a single installed App and its Accessory with AppConfigId <appconfigid>, and to save that backup to file <backupfile>, execute:

% sudo ubos-admin backup --appconfigid <appconfigid> --tobackupfile <backupfile>

To determine the correct <appconfigid>, use ubos-admin listsites --detail.

If your Site uses TLS, and you do not want to store your TLS key material in the backup, execute the backup command with the --notls option.

You can also create a backup as a side effect of a ubos-admin update or ubos-admin undeploy operation: simply add option --backup <backupfile> to the command.

Creating a backup that is stored on a remote host

You can use backup destinations that contain a Data Transfer Protocol as part of their URL. Here are some examples:

  • file:/tmp/my.ubos-backup: the local file /tmp/my.ubos-backup. For convenience, you don’t need the prefix file:.

  • use HTTPS to HTTP “POST” the backup file to this URL. (This requires you have to have suitable software running at that knows what to do with the arriving file!)

  • s3://mybucket/my.ubos-backup: the file my.ubos-backup in Amazon Web Services' Simple Storage Service (S3), bucket mybucket. This requires the amazons3 package to be installed.

  • rsync+ssh:// the file my.ubos-backup uploaded to host as user user, using the rsync protocol over ssh. This requires the ubos-datatransfer-rsync package to be installed.

You can find all Data Transfer Protocols currently available on your Device by executing:

% ubos-admin list-data-transfer-protocols

This will also show available options for these Data Transfer Protocols.

Each of those Data Transfer Protocols may have its own options and particularities. For example, if you use ftp, you may or may not have to turn on “passive mode” (which is a command-line option shown with ubos-admin list-data-transfer-protocols). Some may require usernames, passwords or other credentials. ubos-admin backup will either complain that a necessary option was not provided, or interactively ask you for it. For some Data Transfer Protocols, like ftp for example, it may not be obvious what options are needed for your particular situation; try out different ones until it works.

UBOS will, by default, remember the options and credentials you used for backing up to remote locations. This makes it easier to run the same backup on a regular basis – something we’d like to encourage.

Example: creating a backup that is stored on Amazon S3

As an example, let’s see how UBOS can automatically upload a backup file to your account at Amazon Web Services and store it in its Simple Storage Service (S3).

% sudo pacman -S amazons3

This makes the s3 Data Transfer Protocol available.

You need to have an existing “bucket” on S3 that you are permitted to write to. Let’s assume it is called mybucket. Then, you could invoke the backup to S3 as follows:

% sudo ubos-admin backup --backuptodir s3://mybucket


% sudo ubos-admin backup --backuptofile s3://mybucket/my.ubos-backup

When you invoke this command for the first time, it will ask you for the necessary credential information so it can store the backup on your account at Amazon Web Services. This credential information will be stored on your Device, so you do not need to enter it every time you run a backup.

Specifically, you need to have the Amazon “Access Key ID” and the Amazon “Secret Access Key” for an AWS user that is permitted to create and write the S3 bucket that you specified. Creating this may involve the following steps:

  • Sign up for an Amazon Web Services (AWS) account.

  • In AWS, create an suitable Identity and Access Management (IAM) user, e.g. mybackupuser. This is a user that will only use “programmatic” access.

  • Add the needed permissions to this user by creating a policy, such as:

    • HeadBucket
    • ListBucket
    • CreateBucket
    • PutObject.
  • Create an “Access Key ID” and “Secret Access Key” for that user. Store both of them securely, as Amazon will not show you the Secret Access Key again.

Example: creating a backup that is uploaded via rsync over ssh

If you wanted to back up via rsync over ssh, for example to a home NAS device, first install the ubos-datatransfer-rsync package:

% sudo pacman -S ubos-datatransfer-rsync

This makes the rsync+ssh Data Transfer Protocol available.

Then you need to have a rsync-over-ssh endpoint (e.g. on your NAS) that can be accessed with a SSH keypair; password-based authentication is not supported.

Then you can perform the backup with a command such as:

% sudo ubos-admin backup --idfile <privatekeyfile> --backuptodir rsync+ssh://<server>/directory

where <privatekeyfile> is the SSH private key to be used.

Encrypting a backup

To automatically encrypt a backup before delivering it to its final (local or remote) location, specify --encryptid <id> as an argument to ubos-admin backup. UBOS will look in the GPG keychain of the shepherd user for a GPG public key with identifier <id>, and encrypt the backup file with it.

If you generate the GPG keypair somewhere else than as shepherd on your UBOS Device, importing the public key into the shepherd’s key ring can be as simple as executing:

% gpg --import

and copy-pasting the public key into the terminal, followed by a ^D (for end of file).

Note: Please make sure you understand public and private keys before you do this. Backups are useless if they are encrypted and you can’t decrypt them when you need to! In particular, if you make backups to be able to recover your data if your UBOS Device is lost, stolen, or destroyed, be sure you have the private key needed to decrypt your backups in a safe place that won’t be lost, stolen or destroyed at the same time!

Determining what a backup file contains

To determine the contents of a .ubos-backup file, execute:

% ubos-admin backupinfo --in <backupfile>

This will show information about the backup, such as when it was created, as well as which Sites, Apps and Accessories were backed up.

Restoring from backup

You can restore data either by specifying a local .ubos-backup file (using the --in <backupfile> command-line options) or by specifying an http or https URL from which the backup file will first be downloaded (using the --url <backupurl> command-line options). In this section, we will assume your backup file is local but all commands should work equally with remote files.

To restore all Sites with all Apps and Accessories contained in a .ubos-backup file, execute:

% sudo ubos-admin restore --in <backupfile>

This command will refuse to work if restoring the backup would cause a conflict with a Site that is already installed. Possible conflicts include the following:

  • a currently deployed Site runs at the same hostname as one to be restored;

  • a currently deployed Site has the same SiteId as one to be restored;

  • a currently deployed App has the same AppConfigId as one to be restored;

  • a currently deployed App runs at the same Context Path as one to be restored.

If you wish to restore a previous version of a currently deployed Site from backup, either back up and then undeploy the current Site first, or restore the Site at a new hostname and with new identifiers, using the --createnew options described below.

To restore a Site with a certain SiteId from a backup file <backupfile> to the current Device, but leave all other Sites unchanged, specify the SiteId:

% sudo ubos-admin restore --siteid <siteid> --in <backupfile>

Alternatively, you can use the hostname of the Site that was used at the time of the backup:

% sudo ubos-admin restore --hostname <hostname> --in <backupfile>

To restore only one App, instead of all Apps at a Site, specify the AppConfigId and the hostname of the Site to which the App shall be added:

% sudo ubos-admin restore --appconfigid <appconfigid> --tohostname <tohostname> --in <backupfile>

Alternatively you can use the SiteId of the Site to which the App shall be added:

% sudo ubos-admin restore --appconfigid <appconfigid> --tositeid <tositeid> --in <backupfile>

To copy a Site or AppConfiguration and use new identifiers and a new hostname, use one of the following:

% sudo ubos-admin restore --siteid <fromsiteid> --createnew --newhostname <newhostname> --in <backupfile>

Finally, to replace one or more Apps or Accessory with a different one during restore, use the --migratefrom <package> and --migrateto <package> options, such as:

% sudo ubos-admin restore --migratefrom owncloud --migrateto nextcloud --in <backupfile>

To see the full set of options, invoke:

% ubos-admin restore --help