ConfiguredDaemonSet

Requirements

API Requirements

• Pod template

• Set of nodes on which Pods are to be spawned

• ConfigMap/Secret volume mounts which can be configured per-node

Operative Requirements

• Per configured node, there MUST NOT exist more than one running Pod of a ConfiguredDaemonSet for a longer period of time. The controller MUST attempt to dispose of excess pods immediately.

• Pods of a ConfiguredDaemonSet MUST NOT run on any node not configured explicitly in the ConfiguredDaemonSet spec.

• Upon configuration changes, the controller MUST execute a rolling upgrade of the configuration. The maximum number of Pods which are in the process of being restarted due to the upgrade at the same time is configurable and MUST NOT be exceeded.

• The controller MUST be able to deal with configuration changes which happen while a rolling upgrade for an earlier configuration change is still in progress.

• Invalid configuration (e.g. inconsistent node sets in different config blocks) MUST NOT be applied.

• The controller MAY start pods even if the Secret / ConfigMap they use is not yet present. The downtime caused by that is covered by the maximum number of pods which can be redeployed at the same time.