Tightening the resource lifecycle

[DamianEdwards]

Current runtime lifecycle processing:

• DistributedApplication.StartAsync
  • IDistributedApplicationEventing -> BeforeStartEvent
    • The DistributedApplication.Services collection is built by the time this event is published
    • This event is the last chance to add or remove resources from the DistributedApplicationModel before they're processed by consumers (note you'll likely want to capture the IDistributedApplicationBuilder before this so that you can get instances of IResourceBuilder<TResource> if adding resources)
  • IDistibutedApplicationLifecycleHook.BeforeStartAsync
  • NEW EVENT: IDistributedApplicationEventing -> InitializeResourceEvent
  • IDistributedApplicationEventing -> EndpointsAllocatedEvent
  • IDistibutedApplicationLifecycleHook.EndpointsAllocatedAsync
  • Per DCP controlled resources:
    • IDistributedApplicationEventing -> ConnectionStringAvailableEvent
    • IDistributedApplicationEventing -> BeforeResourceStartedEvent
      • This even can be fired multiple times for a resource, e.g. if it's restarted it will fire each time before it starts
      • This event is the last chance to mutate a resource's annotations before they're processed by consumers
      • The logic for WaitFor is implemented here, so resources must publish this event
  • IDistributedApplicationEventing -> ResourceReadyEvent
    • fires for all resources after health checks are healthy, only once
    • Resources that have a WaitFor relationship to another resource are waiting for this event
  • IDistributedApplicationEventing -> AfterResourcesCreatedEvent
  • IDistibutedApplicationLifecycleHook.AfterResourcesCreatedAsync

[mitchdenny]

It's good to spell this out.