Local Kubernetes testing with KIND

Local Kubernetes testing with KIND

Intro

If you've spent days (or even weeks?) trying to spin up a Kubernetes cluster for learning purposes or to test your application, then your worries are over. Spawned from a Kubernetes Special Interest Group, KIND is a tool that provisions a Kubernetes cluster running IN Docker.

From the docs:

kind is a tool for running local Kubernetes clusters using Docker container "nodes".
kind is primarily designed for testing Kubernetes 1.11+, initially targeting the conformance tests.

Installing KIND

As it is built using go, you will need to make sure you have the latest version of golang installed on your machine.

According to the k8s docs, golang -v 1.11.5 is preferred. To install kind, run these commands (it takes a while):

go get -u sigs.k8s.io/kind
kind create cluster

Then confirm kind cluster is available:

kind get clusters

Setting up kubectl

Also, install the latest kubernetes-cli using Homebrew or Chocolatey.
The latest Docker has Kubernetes feature but it may come with older kubectl . Check its version by running this command:

kubectl version

Make sure it shows GitVersion: "v1.14.1" or above.
If you find you are running kubectlfrom Docker, try brew link or reorder path environment variable.

Once kubectl and kind are ready, open bash console and run these commands:

export KUBECONFIG=”$(kind get kubeconfig-path)”
kubectl cluster-info

If kind is properly set up, some information will be shown.
Now you are ready to proceed. Yay!

Deploying first application

What should we deploy on the cluster? We are going to attempt deploying Cassandra since the docs have a pretty decent walk-through on it.

First of all, download cassandra-service.yaml and cassandra-statefulset.yaml for later. Then create kustomization.yaml by running two cat commands.
Once those yaml files are prepared, layout them as following:

k8s-wp/
  kustomization.yaml
  mysql-deployment.yaml
  wordpress-deployment.yaml

Then apply them to your cluster:

cd k8s-wp
kubectl apply -k ./

Validating (optional)

Get the Cassandra Service.

kubectl get svc cassandra

The response is:

NAME        TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)    AGE
cassandra   ClusterIP   None         <none>        9042/TCP   45s

Note that Service creation might have failed if anything else is returned. Read Debug Services for common issues.

Finishing up

That's really all you need to know to get started with KIND, I hope this makes your life a little easier and lets you play with Kubernetes a little bit more :)