k8s-dummy-operator

A simple demo operator, that manages resources of type Dummy, creates matching Pods and reflects their status to the owning Dummy. Based on Operator SDK.

Getting Started

1. git clone this repository
2. Connect to a Kubernetes cluster (for example minikube)
3. Install the operator to your cluster: make deploy IMG="ghcr.io/m-hofmann/k8s-dummy-operator:v0.0.2"
4. Create two new sample Dummy objects in the default namespace by using kubectl apply -f demo/just_dummies.yaml
5. Watch the status of
   • your newly created Dummy objects: kubectl describe Dummy
   • the Pods: kubectl get pods

If you want to remove the operator, use make undeploy

Development

For developing the operator, you can use the following commands - prerequisite: You're logged into a k8s cluster!

# if you've changed a *_types.go file
make generate
make manifests
# for running the operator on the host
make install run

Once you want to release a version, use this command. It targets GitHub container registry but can be adjusted according to your needs:

make docker-build docker-push IMG="ghcr.io/<YOUR-GITHUB-ACCOUNT-NAME>/k8s-dummy-operator"

TODO

Some ideas for improving this operator:

1. Make created dependent objects more resilient
   1. Add Liveness/Readiness probe to created Pods
   2. Use Deployments instead of Pods to make Dummy scale out
2. Extend Dummy to reflect detailed status messages from Pod (e.g. ImagePullBackoff)
3. Make Controller heal Pod specs if they are changed
4. Implement some tests (and a lot of mocks)

License

Copyright 2023.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.