coredns-manager-operator/docs/develop.md

Getting Started

• You’ll need a Kubernetes to run against.
  • kube-dns service is exposed
  • It is recommended to switch the current context to the kube-system

Go 1.20

The project is done using go1.20.

Install.

# install go.120
go install golang.org/dl/go1.20@latest
GOPATH=`go env GOPATH`
$GOPATH/bin/go1.20 download

# export 
export GOROOT=`$(go env GOPATH)/bin/go1.20 env GOROOT`
export PATH=${GOROOT}/bin:${PATH}

# check version
go version

Running on the cluster

1. Install Instances of Custom Resources:

kubectl apply -k config/samples/

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

make docker-build docker-push IMG=<some-registry>/coredns-manager-operator:tag

3. Update namespace if needed in config/default/kustomization.yaml. Operator shall be installed in the same namespace as your coredns.

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

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

   OR, Alternatively, generate manifests using kustomize.

    make installation-manifests IMG=<some-registry>/coredns-manager-operator:tag
    kubectl apply -f deploy/operator.yaml
   

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 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

   NOTE: You can also run make from-scratch to run all together: recreate kind cluster, set kube-system as current context, generate, manifests, install and run.

Manual test

Since the project does not have unit tests yet, it is recommended to follow the manual QA guide to ensure the quality of the controller. Manual QA Guide

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

License

Copyright 2024 monkale.io.

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.