capi-argocd-controller

This controller adds clusters to ArgoCD when created by CAPI/CAPA.

Prerequisites

This controller makes a few assumptions right now

• CAPI is installed in the cluster this is being deployed to
• ArgoCD is installed in the cluster this is being deploy to
• ArgoCD is installed in the argocd namespace

Quickstart

To release a new image to the registry

echo $GITHUB_TOKEN | docker login ghcr.io -u $GITHUB_USERNAME --password-stdin
make docker-build docker-push

This will release an image to ghcr.io/rossedman/capi-argocd-controller. Once the image is created, then it can be deployed. To deploy the controller, you must be pointed at the correct cluster context you want to deploy to and then run these commands

kubectl config use-context $CLUSTER_NAME
make docker-build docker-push deploy

Setup

Below I am setting up a controller that will watch for cluster-api resources using the operator-sdk framework. This provides us with a scaffolding and testing framework to ensure our controllers work as expected and generates tons of boilerplate code for us. First, let's install the operator-sdk tool

brew install operator-sdk

Below, I'm creating a controller and referencing types that exist in CAPI. I am also skipping the creation of those resources because CAPI creates them for us. This is generating a controller without CRDs.

operator-sdk init \
    --domain=x-k8s.io \
    --repo=github.com/rossedman/capi-argocd-controller

operator-sdk create api \
    --group=cluster \
    --version=v1beta1 \
    --kind=Cluster \
    --resource=false \
    --controller=true

Once we have a controller bootstrapped we need to import the types from cluster-api so we can reference them

go get sigs.k8s.io/cluster-api/api/v1beta1
go get github.com/argoproj/argo-cd/pkg/apis/application/v1alpha1

Once this is downloaded, run these commands

go mod tidy
go mod download

Also important to note, to track resources that are not part of the core Kubernetes API or a CRD we are generating, we need to declare them in the scheme for the controller. This was added in main.go to track cluster api resources

utilruntime.Must(capi.AddToScheme(scheme))