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Kubernetes Simple Development Box

Introduction

This post covers a method to stand up a simple isolated Kubernetes environment using Minikube with the –vm-driver=none option and Vagrant. The –vm-driver option is used to specify which hypervisor minikube will use. The default is virtualbox. Virtualbox is generally fine except in cases where your environment (guest environment in this case) does not support nested virtualization. This is where vm-driver=none provides a solution.
Here we are taking advantage of the –vm-driver=none to invoke the guest’s VM local docker daemon instead of one on a single node virtual box instance which is the default behavior, and using Vagrant to isolate a guest Kubernetes environment from the host. Basically putting minikube on the guest VM rather than having minikube launch a guest VM.

Prerequisits

An environment with Docker, Minikube, and Kubectl. There is a Vagrantfile in the http://github.com/justsomedevnotes/Kubernetes-simple-development-box repository that contains the necessary binaries.

Step 1: Create the Cluster

To start minikube with no vm-driver, simply use the command below. After you run the command you need to update the .kube and .minikube files as shown on the output. I have provided a minikube-start.sh script in the http://github.com/justsomedevnotes/kubernetes-simple-development-box repository that starts minikube and updates the files required. There is also a minikube-destroy.sh as well.

sudo minikube start --vm-driver=none

Or use

cd /vagrant && ./minikube-start.sh

Step 2: Test the Environment

This is pretty basic for illustration purposes to show the box works. We are just going to create a nginx pod, grab its IP, and connect to it. Use the pod.yaml below and paste it in a file. The pod.yaml is also found at the http://github.com/justsomedevnotes/kubernetes-simple-development-box repository.

apiVersion: v1
kind: Pod
metadata:
  name: justapod
spec:
  containers:
  - image: nginx
    name: nnginx  

Use the pod.yaml to create a pod instance  

kubectl create -f pod.yaml

Verify the pod has a status of ‘running’ using the following command.

kubectl get pods

Assuming the justapod pod is running, capture the pod IP.

export PODIP=$(kubectl get pod justapod -o json | jq -r .status.podIP)

Finally, access the nginx container.

curl ${PODIP}
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