Kubernetes - Launch Single Node Kubernetes Cluster

Minikube is a tool that makes it easy to run Kubernetes locally. Minikube runs a single-node Kubernetes cluster inside a VM on your laptop for users looking to try out Kubernetes or develop with it day-to-day.

More details can be found at https://github.com/kubernetes/minikube

Step 1 - Start Minikube

Minikube has been installed and configured in the environment. Check that it is properly installed, by running the minikube version command:

minikube version

Start the cluster, by running the minikube start command:

minikube start

Great! You now have a running Kubernetes cluster in your online terminal. Minikube started a virtual machine for you, and a Kubernetes cluster is now running in that VM.

Step 2 - Cluster Info

The cluster can be interacted with using the kubectl CLI. This is the main approach used for managing Kubernetes and the applications running on top of the cluster.

Details of the cluster and its health status can be discovered via 

kubectl cluster-info

To view the nodes in the cluster using 

kubectl get nodes

If the node is marked as NotReady then it is still starting the components.

This command shows all nodes that can be used to host our applications. Now we have only one node, and we can see that it’s status is ready (it is ready to accept applications for deployment).

Step 3 - Deploy Containers

With a running Kubernetes cluster, containers can now be deployed.

Using kubectl run, it allows containers to be deployed onto the cluster - 

kubectl run first-deployment --image=katacoda/docker-http-server --port=80

The status of the deployment can be discovered via the running Pods - 

kubectl get pods

Once the container is running it can be exposed via different networking options, depending on requirements. One possible solution is NodePort, that provides a dynamic port to a container.

kubectl expose deployment first-deployment --port=80 --type=NodePort

The command below finds the allocated port and executes a HTTP request.

export PORT=$(kubectl get svc first-deployment -o go-template='{{range.spec.ports}}{{if .nodePort}}{{.nodePort}}{{"n"}}{{end}}{{end}}') echo "Accessing host01:$PORT" curl host01:$PORT

The results is the container that processed the request.

Step 4 - Dashboard

The Kubernetes dashboard allows you to view your applications in a UI. In this deployment, the dashboard has been made available on port 30000.

The URL to the dashboard is https://2886795296-30000-ollie02.environments.katacoda.com/