sidecar-injector

A contrived reference example illustrating the use of operator-sdk in developing a basic custom controller that operates on Deployments.

sidecar-injector is intended as the companion repository to What is the Kubernetes Controller Pattern?

Getting Started

You'll need a Kubernetes cluster to run against. You can use KIND to get a local cluster for testing, or run against a remote cluster.

Note: Your controller will automatically use the current context in your kubeconfig file (i.e. whatever cluster kubectl cluster-info shows).

Running on the cluster

1. Install Instances of Custom Resources:

kubectl apply -f config/samples/

2. Build and push your image to the location specified by IMG:

make docker-build docker-push IMG=<some-registry>/sidecar-injector:tag

3. Deploy the controller to the cluster with the image specified by IMG:

make deploy IMG=<some-registry>/sidecar-injector:tag

Uninstall CRDs

To delete the CRDs from the cluster:

make uninstall

Undeploy controller

UnDeploy the controller from the cluster:

make undeploy

How it works

This project uses a Controller which provides a reconcile function responsible for synchronizing resources until the desired state is reached on the cluster.

Test It Out

Run your controller (this will run in the foreground, so switch to a new terminal if you want to leave it running):

make run

Modifying the API definitions

If you are editing the API definitions, generate the manifests such as CRs or CRDs using:

make manifests

NOTE: Run make --help for more information on all potential make targets

More information can be found via the Kubebuilder Documentation