Configuration options

The Java Operator SDK (JOSDK) provides several abstractions that work great out of the box. However, while we strive to cover the most common cases with the default behavior, we also recognize that that default behavior is not always what any given user might want for their operator. Numerous configuration options are therefore provided to help people tailor the framework to their needs.

Configuration options act at several levels, depending on which behavior you wish to act upon:

• Operator-level using ConfigurationService
• Reconciler-level using ControllerConfiguration
• DependentResouce-level using the DependentResourceConfigurator interface
• EventSource-level: some event sources, such as InformerEventSource, might need to be fine-tuned to properly identify which events will trigger the associated reconciler.

Operator-level configuration

Configuration that impacts the whole operator is performed via the ConfigurationService class. ConfigurationService is an abstract class, and the implementation can be different based on which flavor of the framework is used. For example Quarkus Operator SDK replaces the default implementation. Configurations are initialized with sensible defaults, but can be changed during initialization.

For instance, if you wish to not validate that the CRDs are present on your cluster when the operator starts and configure leader election, you would do something similar to:

Operator operator = new Operator( override -> override
        .checkingCRDAndValidateLocalModel(false)
        .withLeaderElectionConfiguration(new LeaderElectionConfiguration("bar", "barNS")));

Reconciler-level configuration

While reconcilers are typically configured using the @ControllerConfiguration annotation, it is also possible to override the configuration at runtime, when the reconciler is registered with the operator instance, either by passing it a completely new ControllerConfiguration instance or by preferably overriding some aspects of the current configuration using a ControllerConfigurationOverrider Consumer:

Operator operator;
Reconciler reconciler;
...
operator.register(reconciler, configOverrider ->
        configOverrider.withFinalizer("my-nifty-operator/finalizer").withLabelSelector("foo=bar"));

DependentResource-level configuration

DependentResource implementations can implement the DependentResourceConfigurator interface to pass information to the implementation. For example, the SDK provides specific support for the KubernetesDependentResource, which can be configured via the @KubernetesDependent annotation. This annotation is, in turn, converted into a KubernetesDependentResourceConfig instance, which is then passed to the configureWith method implementation.

TODO: still subject to change / uniformization

EventSource-level configuration

TODO