Phase 2 Deliverable:

GA or Tech Preview support for a generic interface for administrators to define custom reboot/drain suppression rules. 

Epic Goal

• Allow administrators to define which machineconfigs won't cause a drain and/or reboot.
• Allow administrators to define which ImageContentSourcePolicy/ImageTagMirrorSet/ImageDigestMirrorSet won't cause a drain and/or reboot
• Allow administrators to define alternate actions (typically restarting a system daemon) to take instead.
• Possibly (pending discussion) add switch that allows the administrator to choose to kexec "restart" instead of a full hw reset via reboot.

Why is this important?

• There is a demonstrated need from customer cluster administrators to push configuration settings and restart system services without restarting each node in the cluster. 
• Customers are modifying ICSP/ITMS/IDMS outside post day 1/adding them+
• (kexec - we are not committed on this point yet) Server class hardware with various add-in cards can take 10 minutes or longer in BIOS/POST. Skipping this step would dramatically speed-up bare metal rollouts to the point that upgrades would proceed about as fast as cloud deployments. The downside is potential problems with hardware and driver support, in-flight DMA operations, and other unexpected behavior. OEMs and ODMs may or may not support their customers with this path.

Scenarios

1. As a cluster admin, I want to reconfigure sudo without disrupting workloads.
2. As a cluster admin, I want to update or reconfigure sshd and reload the service without disrupting workloads.
3. As a cluster admin, I want to remove mirroring rules from an ICSP, ITMS, IDMS object without disrupting workloads because the scenario in which this might lead to non-pullable images at a undefined later point in time doesn't apply to me.

Acceptance Criteria

• CI - MUST be running successfully with tests automated
• Release Technical Enablement - Provide necessary release enablement details and documents.
• ...

Dependencies (internal and external)

1. ...

Previous Work (Optional):

1. …

Open questions::

1. …

Done Checklist

• CI - CI is running, tests are automated and merged.
• Release Enablement <link to Feature Enablement Presentation>
• DEV - Upstream code and tests merged: <link to meaningful PR or GitHub Issue>
• DEV - Upstream documentation merged: <link to meaningful PR or GitHub Issue>
• DEV - Downstream build attached to advisory: <link to errata>
• QE - Test plans in Polarion: <link or reference to Polarion>
• QE - Automated tests merged: <link or reference to automated tests>
• DOC - Downstream documentation merged: <link to meaningful PR>