Custom resources allow you to extend the Kubernetes API beyond its default objects like pods and services to manage complex applications.
Popular tools like ArgoCD, Prometheus, and KubeVirt leverage custom resources to provide functionalities like GitOps, monitoring, and virtual machine management.
Implementing a custom resource involves defining its schema with a Custom Resource Definition (CRD), writing the business logic in an operator, and using code generators for boilerplate client code.
The first step in creating a custom resource is designing its specification, as demonstrated by the MongoKube example for automating MongoDB deployments.
A Custom Resource Definition (CRD) file is used to register the new resource's schema, scope, versions, and naming conventions with the Kubernetes API server.
The controller contains the core logic that reacts to changes in custom resource objects, such as creating deployments and services when a new object is applied.
A live demonstration shows how applying a single custom resource manifest triggers the controller to deploy all necessary Kubernetes objects for a MongoDB instance.
Crossplane extends the Kubernetes control plane to manage external cloud provider resources like AWS S3 buckets as if they were native Kubernetes objects.
Custom resources are ideal when you need to manage external resources or implement complex operational logic that goes beyond the templating capabilities of Helm charts.
27:52Maish Saidel-Keesing
57:24Hannes Norbert Göring
21:43Mario Valderrama
31:52Philipp Krenn
48:45Denis Souza Rosa
40:00Rob Richardson
45:49Denis Wilson Souza Rosa & Steffen Schneider
50:02Liviu Costea
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