daemonset-primitive

DaemonSet Primitive Example

This example demonstrates the usage of the daemonset primitive within the operator component framework. It shows how to manage a Kubernetes DaemonSet as a component of a larger application, utilizing features like:

• Base Construction: Initializing a DaemonSet with basic metadata and spec.
• Feature Mutations: Applying version-gated or conditional changes (sidecars, env vars, annotations) using the Mutator.
• Suspension: Demonstrating the delete-on-suspend behavior unique to DaemonSets.
• Data Extraction: Harvesting information from the reconciled resource.

Directory Structure

• app/: Defines the mock ExampleApp CRD and the controller that uses the component framework.
• features/: Contains modular feature definitions:
  • mutations.go: sidecar injection, env vars, and version-based image updates.
• resources/: Contains the central NewDaemonSetResource factory that assembles all features using the daemonset.Builder.
• main.go: A standalone entry point that demonstrates a single reconciliation loop using a fake client.

Running the Example

You can run this example directly using go run:

go run examples/daemonset-primitive/main.go

This will:

1. Initialize a fake Kubernetes client.
2. Create an ExampleApp owner object.
3. Reconcile the ExampleApp components through multiple spec changes.
4. Print the resulting status conditions.