basebandit/crd-greeting

A Basic Kubernetes Custom Resource Definition

Custom Resource Definition (CRD)

The CustomResourceDefinition API resource allows you to define custom resources:
In this project we create a CRD using the below approach:

• Define CustomResourceDefinition using YAML
• Create custom resources using YAML

Later we will add more functionality, for example if we want our CRDs to work like Pods?

• Once CRD is created, Create new Custom Controller on resource handling create/update/delete events.
• To achieve that, we will build a Custom Controller and deploy it to work as an aggregated API for declarative resources using Kubernetes CRDs and kubectl.

Requirements

• Have a k8s cluster up and running. (minikube would do perfectly fine)
• Create the CRD.
  kubectl apply -f crd-greeting.yaml
• Confirm the resource has been successfully created.

└──╼ $ k api-resources 
NAME         SHORTNAMES   APIVERSION                        NAMESPACED   KIND
...
greetings    grt          basebandit.io/v1alpha1            true         Greeting
...

• Go ahead and now create a resource using our above CRD.
  kubectl apply -f test-greeting.yaml
• Confirm it is successfully created.

└──╼ $ k get greetings                    
NAME                  AGE
basebandit-greeting   19m
┌─[lab@basebandit]─[~/github.com/basebandit/kubernetes/crd-greeting] [main ⚡] 
└──╼ $ k get greeting                     
NAME                  AGE
basebandit-greeting   19m
┌─[lab@basebandit]─[~/github.com/basebandit/kubernetes/crd-greeting] [main ⚡] 
└──╼ $ k get grt     
NAME                  AGE
basebandit-greeting   19m

Note: You can switch the name resource name greetings with any of the names you declared in the CRD spec definition.