Using the KernelCare Plug-in

You can use the KernelCare plug-in to patch the Linux kernel on managed hosts without rebooting them. The plug-in provides job templates to view and live-patch the Linux kernel on managed hosts and ensures managed hosts do not report to orcharhino Server that a reboot is required through tracer. For more information, see tuxcare.com/live-patching-services and docs.tuxcare.com/live-patching-services.

The KernelCare plug-in is a technical preview. ATIX AG does not recommend running this in your production environment.

Installing the KernelCare Plug-in

Use the following procedure to install the KernelCare plug-in.

Procedure

On your orcharhino Server, install the plug-in package:
```
# dnf install rubygem-foreman_kernel_care
```
Rerun orcharhino-installer:
```
# orcharhino-installer
```

KernelCare Client

You need to provide the KernelCare client to your managed hosts. Synchronize the required repositories depending on the operating system of your managed hosts.

After synchronization, ensure to make the content consumable to your managed hosts.

Creating KernelCare Repositories for CentOS 7

You need to provide the KernelCare client on managed hosts to live-patch their Linux kernel.

Procedure

In the orcharhino management UI, navigate to Content > Products.
Click Create Product to create a product named KernelCare CentOS. For more information, see Creating a Product in Managing Content.
On the Repositories tab, click New Repository to create a repository of type yum as follows:
- Name: KernelCare CentOS 7
- Upstream URL: https://repo.cloudlinux.com/kernelcare/7/x86_64/
- Optional: Add the KernelCare GPG pub key as content credential: https://repo.cloudlinux.com/kernelcare/RPM-GPG-KEY-KernelCare.
For more information, see Adding RPM Repositories in Managing Content.

Installing the KernelCare Package on Managed Hosts

You can use kernelcare to patch the Linux kernel on managed hosts without rebooting them.

Prerequisite

Your managed hosts have access to the KernelCare repository.

Procedure

In the orcharhino management UI, navigate to Hosts > All Hosts and select one or multiple hosts.
From the Select Action menu, select Schedule Remote Job.
In the Job category field, select Katello via Ansible.
In the Job template field, select Install Package - Katello Ansible Default.
In the Package field, enter kernelcare.
Click Submit to install the package on your managed hosts.

Viewing Patched Kernel Version

You can use a job template to view the patched Kernel version on managed hosts.

Prerequisite

Ensure the kernelcare package is installed on your managed hosts. For more information, see Installing the KernelCare Package on Managed Hosts.

Procedure

In the orcharhino management UI, navigate to Hosts > All Hosts.
Select one or multiple hosts and under Select Action, click Schedule Remote Job.
In the Job category field, select Commands.
In the Job template field, select Kernel version.
Click Submit to view the running Linux kernel version on your hosts.

Live Patching Hosts Using KernelCare Plug-In

You can use kcarectl provided by TuxCare to live-patch the Linux kernel on managed hosts. By default, kcarectl checks for updates every four hours. If the automatic installation of patches is disabled or if you want to install patches manually at a certain time, you can start the process using a remote execution job.

Prerequisites

Ensure your hosts have the kernelcare package installed.
Ensure your hosts run CentOS 7, CentOS 8, or CentOS 9.
Ensure your hosts have access to the internet to connect to cloudlinux.com.

If your host is in a disconnected environment, you can use ePortal by Tuxcare to provide Linux kernel patches. For more information, see docs.tuxcare.com/eportal.

Procedure

In the orcharhino management UI, navigate to Hosts > All Hosts.
Select one or multiple hosts and under Select Action, click * Schedule Remote Job*.
In the Job category field, select Commands.
In the Job template field, select Run Command - SSH Default.
In the command field, enter /usr/bin/kcarectl --update.
Click Submit to update to the latest Linux kernel on your hosts.

Additional Resources

For more information on live-patching managed hosts, see docs.tuxcare.com/live-patching-services.

The text and illustrations on this page are licensed by ATIX AG under a Creative Commons Attribution–Share Alike 3.0 Unported ("CC-BY-SA") license. This page also contains text from the official Foreman documentation which uses the same license ("CC-BY-SA").