Greenboot directories details

You can control how greenboot handles errors by placing your health check scripts in specific directories. The directories determine which scripts are strictly required for a successful boot and which ones can fail without causing a rollback.

Returning a nonzero exit code from any script means that script has failed. Greenboot restarts the system a few times to retry the scripts before attempting to roll back to the previous version.

  • /etc/greenboot/check/required.d contains the health checks that must not fail.

    • If the scripts fail, greenboot retries them three times by default. You can configure the number of retries in the /etc/greenboot/greenboot.conf file by setting the GREENBOOT_MAX_BOOTS parameter to the desired number of retries.

    • After all retries fail, greenboot automatically initiates a rollback if one is available. If a rollback is not available, the system log output shows that manual intervention is required.

    • The 40_microshift_running_check.sh health check script for MicroShift is installed into this directory.

  • /etc/greenboot/check/wanted.d contains health scripts that are allowed to fail without causing the system to be rolled back.

    • If any of these scripts fail, greenboot logs the failure but does not initiate a rollback.

  • /etc/greenboot/green.d contains scripts that run after greenboot has declared the start successful.

  • /etc/greenboot/red.d contains scripts that run after greenboot has declared the startup as failed, including the 40_microshift_pre_rollback.sh prerollback script. This script is executed right before a system rollback. The script performs MicroShift pod and OVN-Kubernetes cleanup to avoid potential conflicts after the system is rolled back to a previous version.

Important

If you customize the values of any environment variable in the /etc/greenboot/greenboot.conf file, these changes can be lost when the greenboot RPM package is updated or downgraded.

  • To retain customizations when building system images with MicroShift, add the greenboot.conf file to a blueprint.

  • To retain customizations when using an RPM installation, apply changes to the greenboot.conf file after you install MicroShift and greenboot RPMs.

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