I am using duplicity with duply to do PGP encrypted backups to Amazon S3. As there are enough guides around for the basic setup (i used Backup unter Linux mit duply), I won’t go into details of that.
However if you are planning to use the new EU (Frankfurt) location called eu-central-1 you will run into problems as this location only supports the V4 authentication.
You might encounter the following error when using duply (even if the config worked on other locations before)
The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256
So what is the solution
This is a bit tricky, as the Debian packages are not up to date and you need to mix backports and unstable versions.
To solve this you will need to upgrade your duplicity and boto framework as following:
Package duplicity needs version > 0.7.02-1
This version is available within the backport branch of Debian. I used package pinning to get this package. You can easily find articles for this via Google, I found this one helpful.
Be careful to understand pinning, as you might confuse APT with a wrong configuration. You should always use sudo apt-cache policy [packagename] and the -s parameter on upgrades first to check what will happen.
Currently I am using duplicity 0.7.06-1~bpo8+1.
Package python-boto needs version >= 2.36.0
Previously this was only available via PyPi, however a newer version is now available in the unstable branch. Hence again you can install this via pinning.
Currently I am using python-boto 2.40.0-1
Package duply did not need additional changes, I am using version 1.9.1-1 out of the regular stable branch