Setting up Duplicati on Ubuntu Jammy (22.04) for Raspberry Pi (RPI) is a great way to ensure your data is securely backed up. Duplicati is a free, open-source backup solution that allows you to store encrypted, incremental, and compressed backups on various cloud storage services and remote file servers. It supports a wide range of storage options, including Amazon S3, Google Drive, Dropbox, Onedrive and many more.

Duplicati uses AES-256 encryption to secure your data before it is uploaded, ensuring your privacy is protected from unauthorized access. The software is designed to handle network issues and interrupted backups efficiently, making it a reliable choice for online backups.

This guide will walk you through the process of installing and configuring Duplicati on your RPI running the 64-bit ARM version of Ubuntu Jammy.

Steps to setup Duplicati:
-Download the latest Duplicati-package (2.0.8.1 as of writing this page)

wget https://updates.duplicati.com/beta/duplicati_2.0.8.1-1_all.deb


Output:
--2024-08-26 11:12:53--  https://updates.duplicati.com/beta/duplicati_2.0.8.1-1_all.deb
Resolving updates.duplicati.com (updates.duplicati.com)... 2606:4700:7::60, 2a06:98c1:58::60, 172.66.0.96, ...
Connecting to updates.duplicati.com (updates.duplicati.com)|2606:4700:7::60|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 32505580 (31M) [application/x-debian-package]
Saving to: ‘duplicati_2.0.8.1-1_all.deb.1’

duplicati_2.0.8.1-1_all.deb.1                   100%[====================================================================================================>]  31.00M  11.3MB/s    in 2.7s

2024-08-26 11:12:56 (11.3 MB/s) - ‘duplicati_2.0.8.1-1_all.deb.1’ saved [32505580/32505580]

-Install the package

apt install ./duplicati_2.0.8.1-1_all.deb

Output:
.....
snip
.....
137 new root certificates were added to your trust store.
Import process completed.
Done
done.
Setting up duplicati (2.0.8.1-1) ...
Setting up mono-devel (6.8.0.105+dfsg-3.2) ...
update-alternatives: using /usr/bin/mono-csc to provide /usr/bin/cli-csc (c-sharp-compiler) in auto mode
update-alternatives: using /usr/bin/resgen to provide /usr/bin/cli-resgen (resource-file-generator) in auto mode
update-alternatives: using /usr/bin/al to provide /usr/bin/cli-al (assembly-linker) in auto mode
update-alternatives: using /usr/bin/sn to provide /usr/bin/cli-sn (strong-name-tool) in auto mode
Setting up mono-xsp4-base (4.2-2.3) ...
Setting up mono-xsp4 (4.2-2.3) ...
Using Mono XSP 4 port: 8084
Binding Mono XSP 4 address: 0.0.0.0
Use of uninitialized value $libs in concatenation (.) or string at /usr/sbin/mono-xsp4-update line 216.
Setting up monodoc-http (4.2-3.1) ...
Use of uninitialized value $libs in concatenation (.) or string at /usr/sbin/mono-xsp4-update line 216.
Processing triggers for libgdk-pixbuf-2.0-0:arm64 (2.42.8+dfsg-1ubuntu0.3) ...

As next we start the Duplicati-service and check if the service is running:

systemctl start duplicati
systemctl status duplicati

Output:
● duplicati.service - Duplicati web-server
     Loaded: loaded (/lib/systemd/system/duplicati.service; disabled; vendor preset: enabled)
     Active: active (running) since Mon 2024-08-26 11:24:22 CEST; 4s ago
   Main PID: 1129 (mono)
      Tasks: 16 (limit: 4422)
     Memory: 55.7M
        CPU: 2.516s
     CGroup: /system.slice/duplicati.service
             ├─1129 DuplicatiServer /usr/lib/duplicati/Duplicati.Server.exe
             └─1133 /usr/bin/mono-sgen /usr/lib/duplicati/Duplicati.Server.exe

Aug 26 11:24:22 raspi24n systemd[1]: Started Duplicati web-server.

Duplicati uses port 8200 and binds the service per default to the loopback-address.

-To get access from remote to the Duplicati Gui edit /etc/default/duplicati and add “–webservice-interface=any” to the DAEMON_OPTS

vi /etc/default/duplicati

# Defaults for duplicati initscript
# sourced by /etc/init.d/duplicati
# installed at /etc/default/duplicati by the maintainer scripts

#
# This is a POSIX shell fragment
#

# Additional options that are passed to the Daemon.
DAEMON_OPTS="--webservice-interface=any"

-Restart the service

systemctl restart duplicati

Now you are able to access the Duplicati-GUI from remote on port 8200:
http://[IP-RPI]:8200

Make sure to set a password , close the page with <OK>:

In case you want to have the service activated at boot-time enable the service at startup:

systemctl enable duplicate

Output:
Created symlink /etc/systemd/system/multi-user.target.wants/duplicati.service → /lib/systemd/system/duplicati.service.

et voilà ! Duplicati is now up and running in a very basic setup.

To increase security make the Duplicati-page secure with adding a PKCS12-Container to have HTTPS-security enabled.

The Daemon-opts statement needs to be enhanced with:
--webservice-sslcertificatefile=[path]
--webservice-sslcertificatepassword=[password (empty is ok]
(in case the PKCS12-Container is unprotected(=no password set)), please keep in mind to add the second statement with an empty password. Additional instructions can be found on the Duplicati-docs.

Example-section:

ADD-ON: example to backup a folder to Onedrive
Duplicati’s robust features, including AES-256 encryption, ensure that your data is securely backed up and protected from unauthorized access. 

This small guide shows you how to create a daily, incremental Backup of a local RPI-folder to Onedrive:

Local folder to Backup: /daten/important_data
Onedrive Backup folder: /Backup/rpi_backup

Access the Duplicati-Gui and add a Backup: