There are several ways to run small Kubernetes clusters: k3s and k3d, minikube, and microk8s to name a few. Currently, my favorite is the Kubernetes provided by Docker Desktop for Mac. But this doesn’t help my friends (or myself) when I am on a Linux laptop. It would be nice to have one lightweight and shared environment for Kubernetes.

Luckily, one of the Kubernetes groups has released KinD - Kubernetes in Docker. In this post I will show how I use KinD for local development of OpenFaaS. I like KinD because, similar to Docker Desktop, it creates a simple single node Kubernetes environment in a Docker container and has a simple kind load command that allows us avoid the push/pull of local development builds of our project.

Creating a dev environment

Start a KinD cluster

Because we are starting a cluster for development of OpenFaaS, I assume that you have go and docker installed already.

# install/upgrade kind
go get -u sigs.k8s.io/kind
# create a cluster
kind create cluster --name dev-openfaas

# verify everything started
export KUBECONFIG="$(kind get kubeconfig-path --name="dev-openfaas")"
kubectl rollout status deploy coredns --watch -n kube-system

Installing Helm

You must have the Helm client installed.

Then, setup the RBAC permissions to make the Helm tiller a cluster admin

kubectl -n kube-system create sa tiller
kubectl create clusterrolebinding tiller \
  --clusterrole cluster-admin \
  --serviceaccount=kube-system:tiller

Then, install Helm into the cluster

# export is not needed if you are in the original terminal used to setup KinD
export KUBECONFIG="$(kind get kubeconfig-path --name="dev-openfaas")"
helm init --skip-refresh --upgrade --service-account tiller

Installing OpenFaaS

First we need to install a vanilla release of OpenFaaS

  1. Setup the default namespaces

    kubectl apply -f https://raw.githubusercontent.com/openfaas/faas-netes/master/namespaces.yml

  2. Setup Gateway basic auth credentials

    export PASSWORD="tester"
kubectl -n openfaas create secret generic basic-auth \
--from-literal=basic-auth-user=admin \
--from-literal=basic-auth-password="$PASSWORD"

  3. Instll OpenFaaS via Helm

    helm repo add openfaas https://openfaas.github.io/faas-netes/
helm repo update
helm upgrade openfaas --install openfaas/openfaas \
    --namespace openfaas  \
    --set basic_auth=true \
    --set functionNamespace=openfaas-fn
kubectl rollout status deploy gateway --watch -n openfaas

    At this point, we have a default OpenFaaS installation isolated in a Docker container. Normally, this would be accessible at http://localhost:31112/ui but this is not exposed yet. Unlike Docker Desktop, NodePort services are not automatically bound to your localhost. Instead, we must manually expose it.

  4. In a separate terminal, we need to expose the

    kubectl -n openfaas port-forward deploy/gateway 31112:8080

  5. Deploy a test function Now that we can access the gateway, we can deploy a test function with the faas-cli

    export GATEWAY=http://localhost:31112
faas-cli login --gateway=$GATEWAY -u admin -p tester
faas-cli store deploy nodeinfo --gateway=$GATEWAY
echo "" | faas-cli invoke nodeinfo --gateway=$GATEWAY

Deploy a local development version of the kubernetes provider

Now that we have this environment created, we can start testing our local development builds.

If I want to test a local branch of the faas-netes project, I use the kind load command to copy the docker image from my local docker into kind cluster. This a lot faster than pushing it to a registry and then pulling it back to my laptop!

make build
kind load docker-image --name dev-openfaas openfaas/faas-netes:latest
export KUBECONFIG="$(kind get kubeconfig-path --name="dev-openfaas")"
helm upgrade openfaas --install openfaas/openfaas \
    --namespace openfaas  \
    --set basic_auth=true \
    --set openfaasImagePullPolicy=IfNotPresent \
    --set faasnetes.imagePullPolicy=IfNotPresent \
    --set faasnetes.image=openfaas/faas-netes:latest \
    --set functionNamespace=openfaas-fn

Cleaning up

If I ever get in trouble and want to start from scratch, I can always recreate the cluster in a minute

kind delete cluster --name dev-openfaas
unset KUBECONFIG

And start again! I have moved most of this into a simple bash script that I have shared as a gist.

KinD provides a lightweight, disposable, and consistent method to test OpenFaaS on Kubernetes without needing a cloud provider or pushing images around the cloud. Going forward, all of my OpenFaaS pull requests will include test instructions that start from a clean cluster using KinD.