README.md

Wing for Kubernetes

A framework for synthesizing Kubernetes manifests using Winglang.

Installation

Install the Wing CLI:

npm i -g winglang

Create a new project and install this library:

mkdir wing-loves-k8s
cd wing-loves-k8s
npm i @winglibs/k8s

Usage

Let's define an app with a simple Kubernetes object:

// main.w
bring k8s;

new k8s.ApiObject(
  apiVersion: "v1",
  kind: "ConfigMap",
  spec: {
    data: {
      key: "value",
    },
  }
);

Now, compile it to YAML:

$ wing compile -t @winglibs/k8s ubuntu.main.w
target/ubuntu.main.k8s

You

The output is a valid K8S YAML is in target/ubuntu.main.k8s:

$ ls target/ubuntu.main.k8s
chart-c86185a7.k8s.yaml

Creating Helm charts

You can set WING_K8S_OUTPUT to helm in order to produce a helm chart instead of simple manifest. This requires a Chart.yaml file next in the current directory.

Default labels and namespace

You can use the WING_K8S_LABELS environment variable to apply labels to all resources in an app. The value is a JSON-encoded map.

The WING_K8S_NAMESPACE variable can be used to specify the default namespace.

export WING_K8S_LABELS='{ "my-label": "123", "your-label": "444" }'
export WING_K8S_NAMESPACE='my-namespace'
wing compile -t @winglibs/k8s main.w

CDK8s Support

This library supports cdk8s and cdk8s-plus, so you can do stuff like this:

npm i cdk8s-plus-27

And then:

bring "cdk8s-plus-27" as k8s;

// lets create a volume that contains our app.
let appData = new k8s.ConfigMap();
appData.addDirectory("./nodejs-app");

let appVolume = k8s.Volume.fromConfigMap(this, "App", appData);

// lets create a deployment to run a few instances of a pod
let deployment = new k8s.Deployment(
  replicas: 3,
);

// now we create a container that runs our app
let appPath = "/var/lib/app";
let port = 80;
let container = deployment.addContainer({
  image: "node:14.4.0-alpine3.12",
  command: ["node", "index.js", "{port}"],
  port: port,
  workingDir: appPath,
});

// make the app accessible to the container
container.mount(appPath, appVolume);

// finally, we expose the deployment as a load balancer service and make it run
deployment.exposeViaService(serviceType: k8s.ServiceType.LOAD_BALANCER);

Roadmap

• Support generating Wing bindings from K8S API specifications and CRDs (cdk8s import).

Maintainers

• Elad Ben-Israel

License

This library is licensed under the MIT License.