Cascading delete for ServiceInstances

[brendandobbs]

Description

When a user deletes a ServiceInstance we would assume that they expect the related ServiceBindings and ServiceBindingUsages to be deleted also. Currently the user needs to delete the ServiceBindings before the ServiceInstances as able to deleted (warning message: "All associated ServiceBindings must be removed before this ServiceInstance can be deleted")

Reasons

Cascading delete of a ServiceInstance would improve the users experience.

Acceptance Criteria

• show idea (and try to make it accepted, could be under alphaFeature) to SC and implement feature on PR,
• under "delete" button when popup displayed, allow user to select: "delete All" with description what will be deleted: SB, SBU.
• feature contributed to upstream SC master

Solution proposal:

• Provide a feature in the Service Catalog istself, where user can flag ServiceInstance during creation/update, and when deleted it will not block removal if SB exists, but will just delete all related SBs and when they are out, SI will be just deleted by SC (that functionality is already in SC)

Next steps:

• popup with warning that all SBUs will be deleted
• when creating SI we need to add "check" cascading delete ON

[mszostok]

treat that task as base groud

• documentation about the new spec (e.g. mention backward compatibility) (in Service Catalog repo)
• implement business logic (change CRD + instance_controller)
• add proper message in status info about new action (deleting SB in background)
• add integration tests for a new logic
• create a task for our Kyma UI (discuss with @kwiatekus)

[piotrmiskiewicz]

After the discussion with @PK85 we decided to have a feature flag which enables cascading deletion for all service instances.

[PK85]

When finished, create an issue to use in Kyma istelf.

[PK85]

@piotrmiskiewicz prepare yourself for 5 min demo during sprint review.

[mszostok]

PR was merged: kubernetes-retired/service-catalog#2711

issue for enabling that in Kyma: #6140 (comment)