Remove old kernel packages in RHEL 8

In RHEL/CentOS 7.x is easy to remove extra kernel packages with package-cleanup, but RHEL 8 yum4 provides a method for removing kernels and keeping only the latest version and running kernel

As you can see we have two kernel packages 4.18.0–240 and 4.18.0.140–15

[buser@lautaro ~]$ rpm -qa | grep kernel-
kernel-tools-4.18.0-240.15.1.el8_3.x86_64
kernel-4.18.0-240.el8.x86_64
kernel-core-4.18.0-240.15.1.el8_3.x86_64
kernel-core-4.18.0-240.el8.x86_64
kernel-tools-libs-4.18.0-240.15.1.el8_3.x86_64
kernel-modules-4.18.0-240.15.1.el8_3.x86_64
kernel-4.18.0-240.15.1.el8_3.x86_64
kernel-modules-4.18.0-240.el8.x86_64

Then we have to remove the oldest one and keep only 1

[buser@lautaro ~]$ sudo yum remove $(yum repoquery --installonly --latest-limit=-1)
Updating Subscription Management repositories.
No match for argument: Updating
No match for argument: Subscription
No match for argument: Management
No match for argument: repositories.
Dependencies resolved.
===============================================================================================
 Package                  Architecture     Version                   Repository           Size
===============================================================================================
Removing:
 kernel                   x86_64           4.18.0-240.el8            @anaconda             0  
 kernel-core              x86_64           4.18.0-240.el8            @anaconda            62 M
 kernel-modules           x86_64           4.18.0-240.el8            @anaconda            21 M
Transaction Summary
===============================================================================================
Remove  3 Packages
Freed space: 83 M
Is this ok [y/N]: y
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                       1/1 
  Erasing          : kernel-4.18.0-240.el8.x86_64                                          1/3 
  Running scriptlet: kernel-4.18.0-240.el8.x86_64                                          1/3 
  Erasing          : kernel-modules-4.18.0-240.el8.x86_64                                  2/3 
  Running scriptlet: kernel-modules-4.18.0-240.el8.x86_64                                  2/3 
  Running scriptlet: kernel-core-4.18.0-240.el8.x86_64                                     3/3 
  Erasing          : kernel-core-4.18.0-240.el8.x86_64                                     3/3 
  Running scriptlet: kernel-core-4.18.0-240.el8.x86_64                                     3/3 
  Verifying        : kernel-4.18.0-240.el8.x86_64                                          1/3 
  Verifying        : kernel-core-4.18.0-240.el8.x86_64                                     2/3 
  Verifying        : kernel-modules-4.18.0-240.el8.x86_64                                  3/3 
Installed products updated.
Removed:
  kernel-4.18.0-240.el8.x86_64                    kernel-core-4.18.0-240.el8.x86_64           
  kernel-modules-4.18.0-240.el8.x86_64
Complete!

then if we query the kernel packages again

[buser@lautaro ~]$ rpm -qa | grep kernel-
kernel-tools-4.18.0-240.15.1.el8_3.x86_64
kernel-core-4.18.0-240.15.1.el8_3.x86_64
kernel-tools-libs-4.18.0-240.15.1.el8_3.x86_64
kernel-modules-4.18.0-240.15.1.el8_3.x86_64
kernel-4.18.0-240.15.1.el8_3.x86_64