Getting to know kubernetes

Getting to know kubernetes by way of minikube

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.

This README will walk you through getting minikube and kubectl installed. After that, you can follow the Hello minikube tutorial section to deploy to your kubernetes cluster.

We are running ...

• macOS Monterey
• on M1 Max chip.
• with Docker Desktop 4.10.1

Getting Started with k8s and minikube

Let's get you up and running.

1. Install minikube

brew install minikube

2. Install kubectl

If you're a GCP user, you may wish to install using the Google Cloud SDK: gcloud components install kubectl

If you're not, you can use homebrew: brew install kubectl

3. Start minikube

minikube start

You'll see something like this:

😄  minikube v1.26.0 on Darwin 12.5 (arm64)
✨  Automatically selected the docker driver
📌  Using Docker Desktop driver with root privileges
👍  Starting control plane node minikube in cluster minikube
🚜  Pulling base image ...
💾  Downloading Kubernetes v1.24.1 preload ...
    > preloaded-images-k8s-v18-v1...: 342.86 MiB / 342.86 MiB  100.00% 3.68 MiB
    > gcr.io/k8s-minikube/kicbase: 347.17 MiB / 347.17 MiB  100.00% 2.94 MiB p/
    > gcr.io/k8s-minikube/kicbase: 0 B [_________________________] ?% ? p/s 49s
🔥  Creating docker container (CPUs=2, Memory=15939MB) ...
🐳  Preparing Kubernetes v1.24.1 on Docker 20.10.17 ...
    ▪ Generating certificates and keys ...
    ▪ Booting up control plane ...
    ▪ Configuring RBAC rules ...
🔎  Verifying Kubernetes components...
    ▪ Using image gcr.io/k8s-minikube/storage-provisioner:v5
🌟  Enabled addons: storage-provisioner, default-storageclass
🏄  Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default

If you have trouble starting

Try running the delete instructions and then re-try the start command.

Post Startup

After it's finished its startup, check status:

minikube status

You'll see something like this:

minikube
type: Control Plane
host: Running
kubelet: Running
apiserver: Running
kubeconfig: Configured

4. Set kubectl context

kubectl config use-context minikube

You'll see something like this:

Switched to context "minikube".

You can verify:

kubectl cluster-info

You'll see something like this:

Kubernetes control plane is running at https://127.0.0.1:61870
CoreDNS is running at https://127.0.0.1:61870/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

5. Open your kubernetes dashboard

minikube dashboard

You'll see something like this:

🔌  Enabling dashboard ...
    ▪ Using image kubernetesui/dashboard:v2.6.0
    ▪ Using image kubernetesui/metrics-scraper:v1.0.8
🤔  Verifying dashboard health ...
🚀  Launching proxy ...
🤔  Verifying proxy health ...
🎉  Opening http://127.0.0.1:62094/api/v1/namespaces/kubernetes-dashboard/services/http:kubernetes-dashboard:/proxy/ in your default browser...

And voila! Your browser will open that URL.

Hello minikube tutorial

This repo is adapted from kubernetes' hello minikube tutorial.

In this tutorial, we will build a docker image and deploy it using kubernetes.

1. Reuse the Docker daemon

Let's point our SHELL to minikube's docker-daemon to do our building.

eval $(minikube -p minikube docker-env)

If you want to be sure it worked, try running docker ps. You'll see all the k8s containers running in minikube.

To unset the environment: eval $(minikube docker-env -u)

2. Build the image

docker build . -t hello-node:v1

3. Create a Deployment

A Kubernetes Pod is a group of one or more Containers, tied together for the purposes of administration and networking. The Pod in this tutorial has only one Container.

A Kubernetes Deployment checks on the health of your Pod and restarts the Pod’s Container if it terminates. Deployments are the recommended way to manage the creation and scaling of Pods.

Create the Deployment

kubectl create deployment hello-node --image=hello-node:v1

View the Deployment

kubectl get deployments

View the Pod

kubectl get pods

4. Create a Service

By default, the Pod is only accessible by its internal IP address within the Kubernetes cluster. To make the hello-node Container accessible from outside the Kubernetes virtual network, you have to expose the Pod as a Kubernetes Service.

kubectl expose deployment hello-node --type=LoadBalancer --port 8080

5. Expose your App

The --type=LoadBalancer flag indicates that you want to expose your Service outside of the cluster. In GCP's Kubernetes Engine, an external IP address would be provisioned to access the Service. In Minikube, the LoadBalancer type makes the Service accessible through the minikube service command:

minikube service hello-node

This will open a browser window to your app. Open your minikube dashboard to have a look around!

6. Shut it down

minikube stop

You'll see something like this:

✋  Stopping node "minikube"  ...
🛑  Powering off "minikube" via SSH ...
🛑  1 node stopped.

7. (Optional) Delete and purge configurations

minikube delete --all --purge

You'll see something like this:

🔥  Deleting "minikube" in docker ...
🔥  Removing /Users/User_Name/.minikube/machines/minikube ...
💀  Removed all traces of the "minikube" cluster.
🔥  Successfully deleted all profiles
💀  Successfully purged minikube directory located at - [/Users/User_Name/.minikube]
📌  Kicbase images have not been deleted. To delete images run:
    ▪ docker rmi gcr.io/k8s-minikube/kicbase:v0.0.32

Resources

• minikubecommand reference
• Kubernetes Web Site
• Play with Kubernetes