As per the draft upstream release notes:

AppArmor 3.0 is a major new release of the AppArmor user space that makes
an important change to policy development and support. Its focus is
transitioning policy to the new features ABI and as such other new features
have been limited.

Apprmor 3.0 is a bridge release between older AppArmor 2.x policy and the
newer AppArmor 3 style policy which requires the declaration of a features
abi. As such AppArmor 3.0 will be a short lived release, and will not
receive long term support. The following AppArmor 3.1 feature release is
planned to be a regular release, please take this into account when
including AppArmor 3.0 into a distro release.

As such, Ubuntu 20.10 provides a great opportunity to introduce AppArmor3
to Ubuntu and provide these new capabilities to users and system
administrators. The short support lifespan of Ubuntu 20.10 ensures that
there is alignment with the limited support lifetime of AppArmor 3.0 from
upstream, whilst giving good exposure and opportunity to test and exercise
the new features in AppArmor 3.x on the road to Ubuntu 22.04. A highlight
of new features provided by AppArmor 3.0 include:

- Policy now must declare the feature abi it was developed for if it is to
  use any new features. This ensures that old policy will not become
  incompatible with new kernels that support additional AppArmor features.
- The use of profile names that are based on pathnames are deprecated.
- Support for new kernel features (requires appropriate features abi
  tagging in policy)
  - upstream v8 network socket rules
  - xattr attachment conditionals
  - capabilities PERFMON and BPF
- Improved compiler warnings and semantic checks
- aa-status rewritten in C (previously was python) with additional features
  - supports use in systems/images where python is not available
  - supports kill, unconfined and mixed profile modes
- Rewritten aa-notify (previously was perl, now python3)
  - shared backend with other python tools
  - support use of aa.CONFDIR instead of hard coded /etc/apparmor
  - improved message layout
- Improved support for kernels that support LSM stacking
- New utility aa-features-abi to extract and work with kernel abi features
- New utility aa-load to load binary policy without calling the
  apparmor_parser
- Support for profile modes
  - enforce (default when no mode flag is supplied)
  - kill (experimental)
  - unconfined (experimental)

The use of the new AppArmor profile feature ABI includes a default
configuration (for the Ubuntu packaged version of AppArmor proposed in this
FFE) for the AppArmor features within the 5.4 Linux kernel - this ensures
that all profiles provided in AppArmor3 for groovy will conform to this
feature set and that upgrades to the kernel version (say to 5.8) that may
include newer AppArmor confinement features will not result in additional
policy denials as a result (since say the existing profile did not specify
a rule for a new AppArmor feature which is now supported by the upgraded
kernel). This ensures that there will be no regressions in application
behaviour as a result of AppArmor kernel feature upgrades.

TESTING

This has been extensively tested by the security team - this includes
following the documented Ubuntu merges test plan for AppArmor and the
extensive QA Regression Tests for AppArmor as well. This ensures that the
various applications that make heavy use of AppArmor (LXD, docker, lxc,
dbus, libvirt, snapd etc) have all been exercised and no regressions have
been observed. All tests have passed and demonstrated both apparmor and the
various applications that use it to be working as expected.

BUILD LOGS

This is currently uploaded to groovy-proposed, build logs can be found on
Launchpad at:
https://launchpad.net/ubuntu/+source/apparmor/3.0.0~beta1-0ubuntu1

INSTALL LOG

See attached for a log showing install of the packages from groovy-proposed