Skip to main content

Getting Started with KubeOps

Prerequisites​

Before you begin, ensure you have the following installed:

Development Environment

For local development, we recommend using kind or Docker Desktop as it provides a lightweight Kubernetes cluster that's perfect for operator development. Make sure your cluster is running before proceeding with the installation steps.

Installing KubeOps Templates​

KubeOps provides templates to help you get started quickly. Install them using the .NET CLI:

dotnet new --install KubeOps.Templates::*

KubeOps offers several template types:

  • operator: Standard operator with demo implementations
  • operator-empty: Minimal operator without web capabilities
  • operator-web: Operator with web server capabilities and demo implementations
  • operator-web-empty: Minimal operator with web server capabilities

Creating Your First Operator​

Let's create a new operator project using the standard template:

dotnet new operator -n MyFirstOperator
cd MyFirstOperator

The template creates a complete operator project structure with:

  • Program.cs: Entry point of your operator
  • Entities/: Directory for your custom resources
  • Controllers/: Directory for your controllers
  • Finalizers/: Directory for your finalizers
  • Webhooks/: Directory for webhooks (if using web operator)

Installing the KubeOps CLI​

The KubeOps CLI helps you manage your operator development workflow. Install it globally:

dotnet tool install --global KubeOps.Cli

Or locally in your project:

dotnet new tool-manifest
dotnet tool install --local KubeOps.Cli

Using the KubeOps CLI​

The CLI provides several useful commands:

Generate Resources​

Generate all necessary Kubernetes resources for your operator:

dotnet kubeops generate operator MyOperator ./MyFirstOperator.csproj
Automatic Generation

The resource generation is automatically included in the build process. You don't need to run the generate command manually unless you want to customize the output location or format.

This command generates:

  • RBAC rules
  • Dockerfile
  • Deployment configuration
  • CRDs (Custom Resource Definitions)
  • Namespace configuration
  • Kustomization files
Webhook Support

If your operator includes webhooks, additional resources are generated:

  • CA and Server certificates
  • Webhook configurations
  • Service definitions
  • Secret generators

Make sure to handle these certificates securely in production environments.

Install CRDs​

Install your operator's CRDs into your Kubernetes cluster:

dotnet kubeops install ./MyFirstOperator.csproj

Uninstall CRDs​

Remove your operator's CRDs from the cluster:

dotnet kubeops uninstall ./MyFirstOperator.csproj

Building Blocks of an Operator​

KubeOps operators are built using several key components:

Custom Resources (Entities)​

Custom resources are defined as C# classes with the [KubernetesEntity] attribute:

[KubernetesEntity(Group = "demo.kubeops.dev", ApiVersion = "v1", Kind = "DemoEntity")]
public class V1DemoEntity : CustomKubernetesEntity<V1DemoEntity.V1DemoEntitySpec, V1DemoEntity.V1DemoEntityStatus>
{
    public class V1DemoEntitySpec
    {
        public string Username { get; set; } = string.Empty;
    }

    public class V1DemoEntityStatus
    {
        public string DemoStatus { get; set; } = string.Empty;
    }
}

Controllers​

Controllers implement the reconciliation logic for your custom resources:

[EntityRbac(typeof(V1DemoEntity), Verbs = RbacVerb.All)]
public class DemoController : IEntityController<V1DemoEntity>
{
    public Task ReconcileAsync(V1DemoEntity entity, CancellationToken cancellationToken)
    {
        // Implement your reconciliation logic here
        return Task.CompletedTask;
    }
}

Finalizers​

Finalizers handle cleanup when resources are deleted:

public class DemoFinalizer : IEntityFinalizer<V1DemoEntity>
{
    public Task FinalizeAsync(V1DemoEntity entity, CancellationToken cancellationToken)
    {
        // Implement your cleanup logic here
        return Task.CompletedTask;
    }
}
Next Steps

The following sections will dive deeper into:

Make sure to read these sections before deploying your operator to production.

Learning Path

Take your time to understand each concept. Building operators is a complex task, but KubeOps makes it more approachable for .NET developers.