Create a repository
mkdir cluster-api-provider-mailgun
cd src/sigs.k8s.io/cluster-api-provider-mailgun
git init
You’ll then need to set up go modules
go mod init github.com/liztio/cluster-api-provider-mailgun
go: creating new go.mod: module github.com/liztio/cluster-api-provider-mailgun
Generate scaffolding
kubebuilder init --domain cluster.x-k8s.io
kubebuilder init will create the basic repository layout, including a simple containerized manager.
It will also initialize the external go libraries that will be required to build your project.
Commit your changes so far:
git commit -m "Generate scaffolding."
Generate provider resources for Clusters and Machines
Here you will be asked if you want to generate resources and controllers. You’ll want both of them:
kubebuilder create api --group infrastructure --version v1alpha1 --kind MailgunCluster
kubebuilder create api --group infrastructure --version v1alpha1 --kind MailgunMachine
Create Resource under pkg/apis [y/n]?
y
Create Controller under pkg/controller [y/n]?
y
The latest API version of Cluster API and the version of your provider do not need to be in sync. Instead, prefer choosing a version that matches the stability of the provider API and its backward compatibility guarantees.
Add Status subresource
The status subresource lets Spec and Status requests for custom resources be addressed separately so requests don’t conflict with each other. It also lets you split RBAC rules between Spec and Status. You will have to manually enable it in Kubebuilder.
Add the subresource:status annotation to your <provider>cluster_types.go <provider>machine_types.go
// +kubebuilder:subresource:status
// +kubebuilder:object:root=true
// MailgunCluster is the Schema for the mailgunclusters API
type MailgunCluster struct {
// +kubebuilder:subresource:status
// +kubebuilder:object:root=true
// MailgunMachine is the Schema for the mailgunmachines API
type MailgunMachine struct {
And regenerate the CRDs:
make manifests
Apply further customizations
The cluster API CRDs should be further customized:
- Apply the contract version label to support conversions (required to deploy any custom resource of your provider)
- Ensure you are compliant with the clusterctl provider contract
Commit your changes
git add .
git commit -m "Generate Cluster and Machine resources."