Azure Linux Ubuntu not fully upgraded

Using apt-get update && apt-get upgrade -y on your Ubuntu VM in Azure sometimes does not upgrade all packages:

root@hostname6:~#
root@hostname6:~#
root@hostname6:~# apt-get update && apt-get upgrade -y
Hit:1 https://packages.microsoft.com/ubuntu/22.04/prod jammy InRelease
Hit:2 http://azure.archive.ubuntu.com/ubuntu jammy InRelease
Hit:3 http://azure.archive.ubuntu.com/ubuntu jammy-updates InRelease
Hit:4 http://azure.archive.ubuntu.com/ubuntu jammy-backports InRelease
Hit:5 http://azure.archive.ubuntu.com/ubuntu jammy-security InRelease
Reading package lists... Done
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
libnss-systemd libpam-systemd libsystemd0 libudev1 linux-azure linux-cloud-tools-azure linux-headers-azure linux-image-azure linux-tools-azure
systemd systemd-sysv udev
0 upgraded, 0 newly installed, 0 to remove and 12 not upgraded.
root@hostname6:~#

Solution

sudo apt-get install aptitude -y
sudo aptitude safe-upgrade

aptitude safe-upgrade
Upgrades installed packages to their most recent version. Installed packages will not be removed unless they are unused [...] Packages which are not currently installed may be installed to resolve dependencies unless the --no-new-installs command-line option is supplied.

Example

root@hostname6:~#
root@hostname6:~# sudo aptitude safe-upgrade
Resolving dependencies...
The following NEW packages will be installed:
linux-azure-6.8-cloud-tools-6.8.0-1041{a} linux-azure-6.8-headers-6.8.0-1041{a} linux-azure-6.8-tools-6.8.0-1041{a}
linux-cloud-tools-6.8.0-1041-azure{a} linux-headers-6.8.0-1041-azure{a} linux-image-6.8.0-1041-azure{a} linux-modules-6.8.0-1041-azure{a}
linux-tools-6.8.0-1041-azure{a}
The following packages will be upgraded:
libnss-systemd libpam-systemd libsystemd0 libudev1 linux-azure linux-cloud-tools-azure linux-headers-azure linux-image-azure linux-tools-azure
systemd systemd-sysv udev
12 packages upgraded, 8 newly installed, 0 to remove and 0 not upgraded.
Need to get 67.2 MB of archives. After unpacking 269 MB will be used.
Do you want to continue? [Y/n/?]

[..]
Current status: 0 (-12) upgradable.
root@hostname6:~#
root@hostname6:~# apt-get update
Hit:1 http://azure.archive.ubuntu.com/ubuntu jammy InRelease
Hit:2 http://azure.archive.ubuntu.com/ubuntu jammy-updates InRelease
Hit:3 http://azure.archive.ubuntu.com/ubuntu jammy-backports InRelease
Hit:4 http://azure.archive.ubuntu.com/ubuntu jammy-security InRelease
Hit:5 https://packages.microsoft.com/ubuntu/22.04/prod jammy InRelease
Reading package lists... Done
root@hostname6:~#
root@hostname6:~# apt-get upgrade
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
root@hostname6:~#
root@hostname6:~#