claudiumocanu / tag-operator

Just a demo for testing and learning. This is not meant to be used in a prod kube cluster

operator-pod-example

Simple operator that labels the pods with claudiu.go/pod-name, if they have a specific annotation claudiu.go/add-pod-name-label=true

operator-sdk commands

Might work with other builds, but I only tested these:

$ operator-sdk version
operator-sdk version: "v1.8.0", commit: "d3bd87c6900f70b7df618340e1d63329c7cd651e", kubernetes version: "1.20.2", go version: "go1.16.4", GOOS: "linux", GOARCH: "amd64"

Generate project

operator-sdk init --domain=claudiu.go --repo=github.com/claudiumocanu/tag-operator

Generate the API and Controller(note that we do not need to create a CRD - this will require some changes in the upcoming build/deploy phase)

operator-sdk create api --group core --version v1 --kind Pod --controller

Run locally

make run

Spawn some pods and annotate them, to trigger the watcher

Create a Pod:

kubectl run --image=nginx my-nginx
kubectl get pod my-nginx --show-labels
kubectl annotate pod my-nginx --overwrite claudiu.go/add-pod-name-label=true
kubectl get pod my-nginx --show-labels

Build and deploy in kube

Because this operator does not create a CRD, some changes are required in the normal build process:

• make sure to bump the version in the Makefile
• make sure to add the IMAGE_TAG_BASE
• generate the manifests and then comment the - ../crd base in the config/default/kustomization.yaml