K8s: Metac Ideas ~ Selectors, Flags, Trigger

[AmitKumarDas]

Need for selectors:

• NameSelector
• LabelSelector
• AnnotationSelector

  NamespaceSelector []string - set on attachments or watch

  FinalizerSelector []string - set on watch or attachments

  WatchAsRefSelector bool - set on attachments; refers to watch

  ResourceRefSelector struct - set on watch or attachments

  resourceRefSelector: "spec.pvcClaimRef"

  NameRefSelector string - set on attachments refers to watch's name

• Is a path available in the attachment resource

  nameRefSelector: "spec.nodeName"

  nameRefSelector: "spec.source.persistentVolumeName"

UIDRefSelector string - set on attachments refers to watch's UID

• Is a path available in the attachment resource

  uidRefSelector: "spec.nodeUID"

  uidRefSelector: "spec.source.persistentVolumeUID"

Boolean / Flag

• IsNoop - Should this entire reconcile operation be forgot?
  • In other words, do not proceed with further reconciliation

Sync/Finalize Hooks as K8s Jobs

• Use of K8s Job as sync or finalize hooks
• Metac will aggregate the current watch & attachments state & pass them as configmaps to K8s Job

Sync/Finalize Hooks as K8s Deployments

• Binary uses Metac as a library
• Binary uses a config (controller specifications) via ConfigMap
• Binary runs a service which in turn
  • Provides the config to Metac lib
  • Implements the sync function exposed by Metac