Follow this tutorial on YouTube here: https://youtu.be/ejLQ5danlIY
Kubernetes is a portable, extensible, open-source platform for managing containerized workloads and services that facilitates both declarative configuration and automation.
Source: https://kubernetes.io/docs/concepts/overview/what-is-kubernetes/
Containers are a good way to bundle and run your applications. In a production environment, you need to manage the containers that run the applications and ensure that there is no downtime. For example, if a container goes down, another container needs to start. Wouldn’t it be easier if this behaviour was handled by a system?
That’s how Kubernetes comes to the rescue! Kubernetes provides you with a framework to run distributed systems resiliently. It takes care of scaling and failover for your application, provides deployment patterns, and more.
Minikube is a tool that makes it easy to run Kubernetes locally. Minikube runs a single-node Kubernetes cluster inside a Virtual Machine (VM) on your laptop for users looking to try out Kubernetes or develop with it day-to-day.
In this example, we’ll use our laptop along with Minikube, VirtualBox and Kubectl to create a single node Kubernetes cluster: (Source picture:Platform9: https://platform9.com/docs/install-kubernetes-the-ultimate-guide/)
I'm assuming you have Virtualbox already setup. If you need a demo on any of these tools, just let me know in the comments.
Install VirtualBox on your system: https://www.virtualbox.org/wiki/Downloads
On windows, MAC OS or Linux, download and install minikube from the following link: https://minikube.sigs.k8s.io/docs/start/
Follow the install procedure first and once complete, continue with these steps.
Minikube gets installed in the C:\ so find the location in file explorer and open up a CMD windows in that directory.
The first install takes a few minutes:
C:\minikube>minikube start
C:\minikube>minikube start
* minikube v1.28.0 on Microsoft Windows 11 Home 10.0.22000 Build 22000
* Automatically selected the virtualbox driver
* Downloading VM boot image ...
> minikube-v1.28.0-amd64.iso....: 65 B / 65 B [---------] 100.00% ? p/s 0s
> minikube-v1.28.0-amd64.iso: 274.45 MiB / 274.45 MiB 100.00% 7.62 MiB p/
* Starting control plane node minikube in cluster minikube
* Downloading Kubernetes v1.25.3 preload ...
> preloaded-images-k8s-v18-v1...: 385.44 MiB / 385.44 MiB 100.00% 7.60 Mi
* Creating virtualbox VM (CPUs=2, Memory=6000MB, Disk=20000MB) ...
! This VM is having trouble accessing https://registry.k8s.io
* To pull new external images, you may need to configure a proxy: https://minikube.sigs.k8s.io/docs/reference/networking/proxy/
* Preparing Kubernetes v1.25.3 on Docker 20.10.20 ...
- Generating certificates and keys ...
- Booting up control plane ...
- Configuring RBAC rules ...
- Using image gcr.io/k8s-minikube/storage-provisioner:v5
* Verifying Kubernetes components...
* Enabled addons: storage-provisioner, default-storageclass
* kubectl not found. If you need it, try: 'minikube kubectl -- get pods -A'
* Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default
Kubectl is part of the minikube install so you can run kubectl commands just by putting minikube infront of it.
But we're going to install kubectl because we want full functionality.
On windows, MAC OS or Linux, download and install kubectl from the following link: https://kubernetes.io/docs/tasks/tools/install-kubectl/
Find your OS and follow the install process. I ran this command from C:\minikube
C:\minikube>curl.exe -LO "https://dl.k8s.io/release/v1.25.0/bin/windows/amd64/kubectl.exe"
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 138 100 138 0 0 123 0 0:00:01 0:00:01 --:--:-- 423
100 43.6M 100 43.6M 0 0 6420k 0 0:00:06 0:00:06 --:--:-- 7793k
Check kubectl commands work:
C:\minikube>kubectl version
WARNING: This version information is deprecated and will be replaced with the output from kubectl version --short. Use --output=yaml|json to get the full version.
Client Version: version.Info{Major:"1", Minor:"25", GitVersion:"v1.25.0", GitCommit:"a866cbe2e5bbaa01cfd5e969aa3e033f3282a8a2", GitTreeState:"clean", BuildDate:"2022-08-23T17:44:59Z", GoVersion:"go1.19", Compiler:"gc", Platform:"windows/amd64"}
Kustomize Version: v4.5.7
Server Version: version.Info{Major:"1", Minor:"25", GitVersion:"v1.25.3", GitCommit:"434bfd82814af038ad94d62ebe59b133fcb50506", GitTreeState:"clean", BuildDate:"2022-10-12T10:49:09Z", GoVersion:"go1.19.2", Compiler:"gc", Platform:"linux/amd64"}
C:\minikube>kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-565d847f94-5zzq5 1/1 Running 0 7m2s
kube-system etcd-minikube 1/1 Running 0 7m15s
kube-system kube-apiserver-minikube 1/1 Running 0 7m15s
kube-system kube-controller-manager-minikube 1/1 Running 0 7m15s
kube-system kube-proxy-zw9qz 1/1 Running 0 7m2s
kube-system kube-scheduler-minikube 1/1 Running 0 7m15s
kube-system storage-provisioner 1/1 Running 1 (6m31s ago) 7m13s
The kubectl command creates a deployment and deployments create our pods and keep them up and running. Lets add the meetup-app into minukube:
C:\minikube>kubectl create deployment meetup-app --image=dmccuk/meetup-app:first --port=80
deployment.apps/meetup-app created
C:\minikube>kubectl get deployment
NAME READY UP-TO-DATE AVAILABLE AGE
meetup-app 1/1 1 1 12s
C:\minikube>kubectl get pods
NAME READY STATUS RESTARTS AGE
meetup-app-9f6b86b86-l5xm8 1/1 Running 0 21s
Lets check out the deployment configuration by checking the yaml file:
C:\minikube>kubectl get deployment -o yaml
apiVersion: v1
items:
- apiVersion: apps/v1
kind: Deployment
metadata:
annotations:
deployment.kubernetes.io/revision: "1"
creationTimestamp: "2022-11-17T11:51:16Z"
generation: 1
labels:
app: meetup-app
name: meetup-app
namespace: default
<results omitted>
Now it’s running we can expose it outside of Kubernetes:
C:\minikube>kubectl expose deployment meetup-app --type=NodePort
service/meetup-app exposed
Other options are available to expose your deployment. These include Port-forwarding, NodePort & Load-balancer.
Once we expose out app, we can check the service. There is our exposed IP address:
C:\minikube>kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 99m
meetup-app NodePort 10.97.162.135 <none> 80:30219/TCP 19s
C:\minikube>minikube service meetup-app --url
http://192.168.59.100:30219
** You can visit the service on in your browser!**
C:\minikube>kubectl scale deployment meetup-app --replicas=3
deployment.apps/meetup-app scaled
And to prove it:
C:\minikube>kubectl get po
NAME READY STATUS RESTARTS AGE
meetup-app-9f6b86b86-8vxsb 1/1 Running 0 15s
meetup-app-9f6b86b86-l5xm8 1/1 Running 0 3m18s
meetup-app-9f6b86b86-nhfcf 1/1 Running 0 15s
We can also get the individual end points:
C:\minikube>kubectl get ep meetup-app
NAME ENDPOINTS AGE
meetup-app 172.17.0.3:80,172.17.0.4:80,172.17.0.5:80 2m13s
C:\minikube>kubectl get po -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
meetup-app-9f6b86b86-8vxsb 1/1 Running 0 45s 172.17.0.4 minikube <none> <none>
meetup-app-9f6b86b86-l5xm8 1/1 Running 0 3m48s 172.17.0.3 minikube <none> <none>
meetup-app-9f6b86b86-nhfcf 1/1 Running 0 45s 172.17.0.5 minikube <none> <none>
Testing: If we delete 2 of the pods, what’s going to happen?
C:\minikube>kubectl delete po meetup-app-9f6b86b86-l5xm8 meetup-app-9f6b86b86-nhfcf
pod "meetup-app-9f6b86b86-l5xm8" deleted
pod "meetup-app-9f6b86b86-nhfcf" deleted
C:\minikube>kubectl get po
NAME READY STATUS RESTARTS AGE
meetup-app-9f6b86b86-8vxsb 1/1 Running 0 87s
meetup-app-9f6b86b86-mxc8v 1/1 Running 0 11s
meetup-app-9f6b86b86-snn66 1/1 Running 0 11s
** They get recreated again!!**
C:\minikube>minikube service meetup-app --url
http://192.168.59.100:30219
C:\minikube>minikube service meetup-app
|-----------|------------|-------------|-----------------------------|
| NAMESPACE | NAME | TARGET PORT | URL |
|-----------|------------|-------------|-----------------------------|
| default | meetup-app | 80 | http://192.168.59.100:30219 |
|-----------|------------|-------------|-----------------------------|
* Opening service default/meetup-app in default browser...
C:\minikube>kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 103m
meetup-app NodePort 10.97.162.135 <none> 80:30219/TCP 4m32s
C:\minikube>kubectl describe svc meetup-app
Name: meetup-app
Namespace: default
Labels: app=meetup-app
Annotations: <none>
Selector: app=meetup-app
Type: NodePort
IP Family Policy: SingleStack
IP Families: IPv4
IP: 10.97.162.135
IPs: 10.97.162.135
Port: <unset> 80/TCP
TargetPort: 80/TCP
NodePort: <unset> 30219/TCP
Endpoints: 172.17.0.4:80,172.17.0.5:80,172.17.0.6:80
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
C:\minikube>minikube dashboard
* Enabling dashboard ...
- Using image docker.io/kubernetesui/dashboard:v2.7.0
- Using image docker.io/kubernetesui/metrics-scraper:v1.0.8
* Some dashboard features require the metrics-server addon. To enable all features please run:
minikube addons enable metrics-server
* Verifying dashboard health ...
* Launching proxy ...
* Verifying proxy health ...
* Opening http://127.0.0.1:56996/api/v1/namespaces/kubernetes-dashboard/services/http:kubernetes-dashboard:/proxy/ in your default browser...
A browser will open and you will see the cluster and information displayed on the webpage. Take a look around.
Either close the browser or press “Ctrl + c” to close it from the command line.
- Built a docker container for a static website.
- Pushed your container to the Docker hub
- Installed and setup minikube and kubectl on you Laptop
- Started a Kubernetes cluster an ran the container image
- Exposed the container deployment and port
- Used minikube to start the container as a Kubernetes service adding replicas
- Finally started up the Kubernetes dashboard to display information about our cluster and pod.
Now that we’ve used Kubernetes to run out container, we can delete the deployment and service.
First, let’s get all the information from Kubernetes that we need to delete it:
C:\minikube>kubectl get all
NAME READY STATUS RESTARTS AGE
pod/meetup-app-9f6b86b86-8vxsb 1/1 Running 0 5m49s
pod/meetup-app-9f6b86b86-mxc8v 1/1 Running 0 4m33s
pod/meetup-app-9f6b86b86-snn66 1/1 Running 0 4m33s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 106m
service/meetup-app NodePort 10.97.162.135 <none> 80:30219/TCP 7m31s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/meetup-app 3/3 3 3 8m52s
NAME DESIRED CURRENT READY AGE
replicaset.apps/meetup-app-9f6b86b86 3 3 3 8m52s
Now, run this command:
C:\minikube>kubectl delete deploy/meetup-app svc/meetup-app
deployment.apps "meetup-app" deleted
service "meetup-app" deleted
All that’s left is the minikube cluster.
C:\minikube>kubectl get all
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 107m
Lets stop Minikube:
C:\minikube>minikube stop
* Stopping node "minikube" ...
* 1 node stopped.
All done! Great work.
If you#re looking to get into learning kubernetes in more detail, I can highly recommend James Spurin. Checkout his Youtube channel here: https://www.youtube.com/@DiveInto
This was just a quick introduction into Docker and Kubernetes. I hope you had some fun.
Good luck in your Journey!