unattended-upgrades: everything except new major versions

Question

I want unattended-upgrades to upgrade everything automatically on my Debian bullyseye system, except for new major version (i.e. not bookworm, when it's released).

I couldn't find anything describing this scenario, and I had a couple of ideas of how to do this:

Unattended-Upgrade::Origins-Pattern {
      "origin=*";
}

Unattended-Upgrade::Package-Blacklist {
      "origin=Debian,codename=^((?!bullseye).)*";
};

Or this:

Unattended-Upgrade::Origins-Pattern {
      "origin=*";
}

Unattended-Upgrade::Package-Blacklist {
      "origin=Debian,codename=bookworm";
};

Can anyone give me some guidance on whether either of these would work, or whether there's a better strategy?

Answer 1

This isn’t determined by unattended-upgrades, it’s determined by the repositories you have configured. If your Debian repositories are selected by codename (bullseye), and you only have those configured, unattended-upgrades won’t upgrade you automatically to the next release of Debian.

(In other words, don’t specify stable in /etc/apt/sources.list etc.)