The Boot Orchestration Service (BOS) consists of many different micro-services and other components, including the API, operators, and the BOS state reporter.
The API is the point of contact for the user and all other services, including BOS’ own services, that want to query or update BOS data.
BOA was a feature of BOS v1 only. It was a Kubernetes job that was responsible for tracking all of the components in a BOS session and taking actions against them.
The BOS operators were introduced in BOS v2. Rather than relying on a single actor to handle all components and actions, the actions are broken up against several operators that monitor for components that require a specific action and handle only those components.
actual-state-cleanupconfigurationdiscoverypower-off-forcefulpower-off-gracefulpower-onsession-cleanupsession-completionsession-setupstatusactual-state-cleanupThis operator clears the actual_state field for components when the field has not been updated with the component_actual_state_ttl time.
This ensures that BOS keeps accurate information on the state of all components.
See Options for more information on setting component_actual_state_ttl option, which controls how long this data is valid if it is not updated.
configurationThis operator is responsible for setting the desired configuration in CFS for components that are in the configuring phase of the boot process.
Because the power-on sets the desired configuration prior to booting components, this is typically only needed when booting to the same boot artifacts, but with a different configuration.
discoveryThis operator periodically checks with HSM to discover new components and create the component records for BOS.
power-off-forcefulThis operator calls PCS to forcefully power off components when a previous power off action fails to power off the component.
power-off-gracefulThis operator calls PCS to gracefully power off components for components that have a power-off-pending status.
power-onThis operator calls PCS to power on components for components that have a power-on-pending status.
session-cleanupThis operator deletes session from BOS that are older than the cleanup_completed_session_ttl value.
session-completionThis operator marks sessions as complete and saves a final status for the session when all components that a session is responsible for have been disabled.
session-setupThis operator monitors for pending sessions, and translates the session template into a list of components and the boot artifacts and configuration to be set as the desired state for those components.
statusThis operator monitors all components that are enabled in BOS and sets their phase based on the components desired and current state in BOS, the components power state as reported by HSM, and the component’s configuration status as reported by CFS.
The bos-state-reporter was introduced in BOS v2. It runs on all components managed by BOS and periodically reports back the actual state of the component it runs on.
This is installed as a package at image customization time.
See Options for more information on setting component_actual_state_ttl option, which controls how long this data is valid if it is not updated.