cdr-operator

Sample kubernetes operator implementing the custom resoures and resouce-specific logic used by ArgoCD ApplicationSet Controller Cluster Decision Resource generator

Description

This sample kubernetes operator defines and constructs the custom resource definition(CRD) of type "ClusterDecisionResource". It also builds a controller to watch the CRs of this custom type along with an external ConfigMap which contains the ArgoCD managed cluster and their corresponding status. It implements sample logic to create the "decisions" list of clusters from comparing the desired clusters along with the max number of clusters to deploy to in the CR with the data from the ConfigMap in order to avoid deploying to clusters in Maintenance mode. These CRs are read via duck-typing by the ArgoCD ApplicationSet Controller Cluster Decision Resource generator

Sample yaml resouces for CRs and configmaps can be found in config/samples folder

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>/cdr-operator:tag

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

make deploy IMG=<some-registry>/cdr-operator:tag

Uninstall CRDs

To delete the CRDs from the cluster:

make uninstall

Undeploy controller

UnDeploy the controller from the cluster:

make undeploy

Contributing

This is a sample project. Contributions are welcomed as various samples.

How it works

This project aims to follow the Kubernetes Operator pattern.

It uses Controllers, which provide a reconcile function responsible for synchronizing resources until the desired state is reached on the cluster.

Test It Out

1. Install the CRDs into the cluster:

make install

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

make run

NOTE: You can also run this in one step by running: make install 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

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.