intro
a small operator demo which only watches car cr's events.
environment:
ubuntu-20.04-amd64
k3s-1.21
docker-20.10.7
go-1.17
tools
download dependences
go mod get -u ./...
go mod vendor
code generate
sudo chmod +x vendor/k8s.io/code-generator/generate-groups.sh
make code_gen
build controller
make build
run controller
make run
regist CRD
kubectl apply -f crd/car.yaml
create CR
kubectl apply -f cr/car.yaml
get CR info
kubectl describe car example-car
practice
regist crd and run controller, you will get:
go run . -kubeconfig /etc/rancher/k3s/k3s.yaml -alsologtostderr=true
I1116 15:47:20.211328 746138 controller.go:82] Setting up event handlers
I1116 15:47:20.211944 746138 controller.go:112] Starting car control loop
I1116 15:47:20.211955 746138 controller.go:114] Waiting for informer caches to sync
I1116 15:47:20.312421 746138 controller.go:119] Starting workers
I1116 15:47:20.312485 746138 controller.go:125] Starting workers
if you create or update a example-car cr in k3s/k8s, you will get:
I1116 15:47:47.780189 746138 controller.go:181] Successfully synced 'default/example-car'
I1116 15:47:47.780265 746138 event.go:282] Event(v1.ObjectReference{Kind:"Car", Namespace:"default", Name:"example-car", UID:"50d0c928-1e1c-4c68-aafd-37a832d576c3", APIVersion:"samplecrd.github.com/v1", ResourceVersion:"61815", FieldPath:""}): type: 'Normal' reason: 'Synced' Car synced successfully
if you delete this cr, you will get:
W1116 15:57:31.026478 746138 controller.go:209] Car: default/example-car does not exist in local cache, will delete it from carset
I1116 15:57:31.026807 746138 controller.go:212] Deleting Car: default/example-car ...
I1116 15:57:31.026816 746138 controller.go:181] Successfully synced 'default/example-car'
