Disable Ctrl-Alt-Del Reboot Activation

Description

By default, SystemD will reboot the system if the Ctrl-Alt-Del key sequence is pressed.

To configure the system to ignore the Ctrl-Alt-Del key sequence from the command line instead of rebooting the system, create a MachineConfig similar to the following:

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 75-master-disable-ctrlaltdel-reboot
spec:
  config:
    ignition:
      version: 3.1.0
    systemd:
      units:
      - name: ctrl-alt-del.target
        mask: true
EOF

This will mask the ctrl-alt-del.target systemd target for all the nodes labeled with the "master" role.

Note that this needs to be done for each MachineConfigPool

For more information on how to configure nodes with the Machine Config Operator see the relevant documentation.

Rationale

A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.