This project is a component of the Operator Framework, an open source toolkit to manage Kubernetes native applications, called Operators, in an effective, automated, and scalable way. Read more in the introduction blog post.

Helm App Operator Kit

This repository serves as a template for easily creating managed stateless applications that run either Kubernetes Deployments or Helm charts. It was inspired by the Lostromos project. The underlying Operator was created using the operator-sdk new command.

Installing a custom Helm-based app

While the Operator Lifecycle Manager can only manage Operators, not all applications require developers to write a custom Operator. The Helm App Operator Kit makes it possible to leverage a pre-existing Helm chart to deploy Kubernetes resources as a unified application.

git clone https://github.com/coreos/helm-app-operator-kit
cd helm-app-operator-kit

Prerequisites

Kubernetes 1.9+ cluster
docker client
kubectl client
Helm Chart

Instructions

Run the following:

$ git checkout [email protected]:operator-framework/helm-app-operator-kit.git && cd helm-app-operator-kit
$ docker build -t quay.io/<namespace>/<chart>-operator -e HELM_CHART=/path/to/helm/chart -e API_VERSION=<group/version> -e KIND=<Kind> .
$ docker push quay.io/<namespace>/<chart>-operator

Modify the following Kubernetes YAML manifest files in helm-app-operator/deploy:

File	Action
`deploy/crd.yaml`	Define your CRD (`kind`, `spec.version`, `spec.group` must match the `docker build` args)
`deploy/cr.yaml`	Make an instance of your custom resource (`kind`, `apiVersion` *must match the `docker build` args)
`deploy/operator.yaml`	Replace `<namespace>` and `<chart>` appropriately
`deploy/rbac.yaml`	Ensure the resources created by your chart are properly listed
`deploy/csv.yaml`	Replace fields appropriately. Define RBAC in `spec.install.spec.permissions`. Ensure `spec.customresourcedefinitions.owned` correctly contains your CRD
`deploy/olm-catalog/crd.yaml`	Define your CRD (`kind`, `spec.version`, `spec.group` must match the `docker build` args)

Apply the manifests to your Kubernetes cluster (if using Operator Lifecycle Manager):

$ kubectl create -f helm-app-operator/deploy/olm-catalog/crd.yaml
$ kubectl create -n <operator-namespace> -f helm-app-operator/deploy/olm-catalog/csv.yaml

Otherwise, manually create the RBAC and deployment resources:

$ kubectl create -f helm-app-operator/deploy/crd.yaml
$ kubectl create -n <operator-namespace> -f helm-app-operator/deploy/rbac.yaml
$ kubectl create -n <operator-namespace> -f helm-app-operator/deploy/operator.yaml

Creating an instance of the example application

After the CustomResourceDefinition and ClusterServiceVersion-v1 resources for the new application have been applied, new instances of that app can be created:

$ kubectl create -n <operator-namespace> -f helm-app-operator/deploy/cr.yaml

Confirm the resources defined in the Helm Chart were created.

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