Red Hat build of MicroShift

Included greenboot health checks

By default, Red Hat Enterprise Linux for Edge (RHEL for Edge) includes a set of built-in greenboot health checks designed to verify functions, such as network connectivity to update repositories and hardware watchdog status. Health check scripts are available in /usr/lib/greenboot/check, a read-only directory in Red Hat Enterprise Linux for Edge (RHEL for Edge) image mode for RHEL systems.

The following health checks are included with the greenboot-default-health-checks framework.

Check if repository URLs are still DNS solvable:

This script is under /usr/lib/greenboot/check/required.d/01_repository_dns_check.sh and ensures that DNS queries to repository URLs are still available.
Check if update platforms are still reachable:

This script is under /usr/lib/greenboot/check/wanted.d/01_update_platform_check.sh and tries to connect and get a 2XX or 3XX HTTP code from the update platforms defined in /etc/ostree/remotes.d.
Check if the current boot has been triggered by the hardware watchdog:

This script is under /usr/lib/greenboot/check/required.d/02_watchdog.sh and checks whether the current boot has been watchdog-triggered or not.
- If the watchdog-triggered reboot occurs within the grace period, the current boot is marked as red. Greenboot does not trigger a rollback to the previous deployment.
- If the watchdog-triggered reboot occurs after the grace period, the current boot is not marked as red. Greenboot does not trigger a rollback to the previous deployment.
- A 24-hour grace period is enabled by default. This grace period can be either disabled by modifying GREENBOOT_WATCHDOG_CHECK_ENABLED in /etc/greenboot/greenboot.conf to false, or configured by changing the GREENBOOT_WATCHDOG_GRACE_PERIOD=number_of_hours variable value in /etc/greenboot/greenboot.conf.