Add A New Etcd Cluster Component

etcd-druid defines an Operator which is responsible for creation, deletion and update of a resource that is created for an Etcd cluster. If you want to introduce a new resource for an Etcd cluster then you must do the following:

• Add a dedicated package for the resource under component.

• Implement Operator interface.

• Define a new Kind for this resource in the operator Registry.

• Every resource a.k.a Component needs to have the following set of default labels:

  • app.kubernetes.io/name - value of this label is the name of this component. Helper functions are defined here to create the name of each component using the parent Etcd resource. Please define a new helper function to generate the name of your resource using the parent Etcd resource.
  • app.kubernetes.io/component - value of this label is the type of the component. All component type label values are defined here where you can add an entry for your component.
  • In addition to the above component specific labels, each resource/component should have default labels defined on the Etcd resource. You can use GetDefaultLabels function.

  These labels are also part of recommended labels by kubernetes. NOTE: Constants for the label keys are already defined here.

• Ensure that there is no wait introduced in any Operator method implementation in your component. In case there are multiple steps to be executed in a sequence then re-queue the event with a special error code in case there is an error or if the pre-conditions check to execute the next step are not yet satisfied.

• All errors should be wrapped with a custom DruidError.