/cloud-provider-kind

Cloud provider for KIND clusters

Primary LanguageGoApache License 2.0Apache-2.0

Kubernetes Cloud Provider for KIND

KIND has demonstrated to be a very versatile, efficient, cheap and very useful tool for Kubernetes testing. However, KIND doesn't offer capabilities for testing all the features that depend on cloud-providers, specially the Load Balancers, causing a gap on testing and a bad user experience, since is not easy to connect to the applications running on the cluster.

cloud-provider-kind aim to fill this gap and provide an agnostic and cheap solution for all the Kubernetes features that depend on a cloud-provider using KIND.

Install

You can install cloud-provider-kind by downloading the binary from the release page. On linux:

curl -Lo ./cloud-provider-kind https://github.com/kubernetes-sigs/cloud-provider-kind/releases/download/v0.0.1/cloud-provider-kind-linux-amd64
chmod +x ./cloud-provider-kind
sudo mv ./cloud-provider-kind  /usr/local/bin/cloud-provider-kind

You can also build it locally:

git clone https://github.com/kubernetes-sigs/cloud-provider-kind.git
Cloning into 'cloud-provider-kind'...
remote: Enumerating objects: 6779, done.
remote: Counting objects: 100% (6779/6779), done.
remote: Compressing objects: 100% (4225/4225), done.q
remote: Total 6779 (delta 2150), reused 6755 (delta 2135), pack-reused 0
Receiving objects: 100% (6779/6779), 9.05 MiB | 1.83 MiB/s, done.
Resolving deltas: 100% (2150/2150), done.

cd cloud-provider-kind && make
sudo mv .bin//cloud-provider-kind  /usr/local/bin/cloud-provider-kind

How to use it

Run a KIND cluster:

$ kind create cluster
Creating cluster "kind" ...
 ✓ Ensuring node image (kindest/node:v1.26.0) 🖼
 ✓ Preparing nodes 📦
 ✓ Writing configuration 📜
 ✓ Starting control-plane 🕹️
 ✓ Installing CNI 🔌
 ✓ Installing StorageClass 💾
Set kubectl context to "kind-kind"
You can now use your cluster with:

kubectl cluster-info --context kind-kind

Have a question, bug, or feature request? Let us know! https://kind.sigs.k8s.io/#community 🙂

Note

Control-plane nodes need to remove the special label node.kubernetes.io/exclude-from-external-load-balancers to be able to access the workloads running on those nodes using a LoadBalancer Service.

$ kubectl label node kind-control-plane node.kubernetes.io/exclude-from-external-load-balancers-
node/kind-control-plane unlabeled

Once the cluster is running, we need to run the cloud-provider-kind in a terminal and keep it running. The cloud-provider-kind will monitor all your KIND clusters and Services with Type LoadBalancer and create the correponding LoadBalancer containers that will expose those Services.

bin/cloud-provider-kind
I0416 19:58:18.391222 2526219 controller.go:98] Creating new cloud provider for cluster kind
I0416 19:58:18.398569 2526219 controller.go:105] Starting service controller for cluster kind
I0416 19:58:18.399421 2526219 controller.go:227] Starting service controller
I0416 19:58:18.399582 2526219 shared_informer.go:273] Waiting for caches to sync for service
I0416 19:58:18.500460 2526219 shared_informer.go:280] Caches are synced for service
...

Creating a Service and exposing it via a LoadBalancer

Let's create an application that listens on port 8080 and expose it in the port 80 using a LoadBalancer.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: policy-local
  labels:
    app: MyLocalApp
spec:
  replicas: 1
  selector:
    matchLabels:
      app: MyLocalApp
  template:
    metadata:
      labels:
        app: MyLocalApp
    spec:
      containers:
      - name: agnhost
        image: registry.k8s.io/e2e-test-images/agnhost:2.40
        args:
          - netexec
          - --http-port=8080
          - --udp-port=8080
        ports:
        - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: lb-service-local
spec:
  type: LoadBalancer
  externalTrafficPolicy: Local
  selector:
    app: MyLocalApp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 8080
$ kubectl apply -f examples/loadbalancer_etp_local.yaml
deployment.apps/policy-local created
service/lb-service-local created
$ kubectl get service/lb-service-local
NAME               TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
lb-service-local   LoadBalancer   10.96.207.137   192.168.8.7   80:31215/TCP   57s

We can see how the EXTERNAL-IP field contains an IP, and we can use it to connect to our application.

$ curl  192.168.8.7:80/hostname
policy-local-59854877c9-xwtfk

$  kubectl get pods
NAME                            READY   STATUS    RESTARTS   AGE
policy-local-59854877c9-xwtfk   1/1     Running   0          2m38s

Note

Only tested with docker and Linux, but podman and Windows and Macusers feedback will be helpful to support those platforms.

The project is still in very alpha state, bugs are expected, please report them back opening a Github issue.

Code of conduct

Participation in the Kubernetes community is governed by the Kubernetes Code of Conduct.