What is minikube?
Minikube is a lightweight and open-source tool that enables developers to run a single-node Kubernetes cluster on their local machine. It facilitates local testing and development of applications on Kubernetes without the need for a full-scale cluster setup.
Features of minikube
Local Kubernetes Cluster: It allows developers to set up a single-node Kubernetes cluster on their local machine, providing an environment for testing and developing applications.
Cross-platform: Minikube supports various operating systems like Windows, macOS, and Linux, making it accessible to a wide range of developers.
Cluster Management: Developers can easily start, stop, and delete clusters, enabling quick iterations during the development process.
Add-ons and Plugins: Minikube supports various add-ons and plugins, allowing users to customize the cluster's behavior and add additional functionality as needed.
Easy Deployment: It simplifies the deployment of Kubernetes workloads, making it an ideal choice for local development, learning, and experimentation.
Docker Integration: Minikube seamlessly integrates with Docker, enabling developers to use their existing Docker images with Kubernetes.
Resource Constraints: It allows users to specify resource constraints for the virtual machine running the Kubernetes cluster, making it suitable for machines with limited resources.
Kubernetes Version Management: Developers can choose specific versions of Kubernetes to run on Minikube, ensuring compatibility with their application's target environment.
Define Pod
A Pod is the smallest deployable unit in Kubernetes, representing a single instance of a running process. It can contain one or more tightly coupled containers that share the same network namespace and can communicate with each other using the localhost. Pods are scheduled to run on nodes in the cluster and can be horizontally scaled up or down. They provide an isolated environment for applications and include shared resources like storage volumes and IP addresses. Pods are designed to be ephemeral and can be easily replaced or rescheduled in case of failures.
Task 1: Install Minikube on your local
Create a new VM instance having 2 CPUs, 4GB of free memory, 20 GB of free disk space.
When creating a new EC2 instance select t2.medium.
Install Docker in your system.
sudo apt update -y
sudo apt install docker.io -y
sudo systemctl start docker
sudo systemctl enable docker
sudo systemctl status docker
sudo usermod -aG docker $USER && newgrp docker
Install Minikube in the system.
curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install minikube-linux-amd64 /usr/local/bin/minikube
And then install Kubelet.
sudo snap install kubectl --classic
Start Minikube as per the image and check Minikube status
minikube start --driver=docker
Check if minikube cluster has been set up successfully or not by checking pods or namespace status.
kubectl get pods
kubectl get namespace
Task 2: Create your first pod on Kubernetes through minikube.
To create a pod, we have to write a YAML file which is a.k.a Manifest file. So to create a pod for NGINX we have to pass the values & attributes in key-value format.
In the manifest file, we are passing values:
apiVersion → Kubernetes Version
Kind → Type of deployment
metadata → More Details about pod
container → Details of containers in object
containerPort → The port where the pod will deploy
apiVersion: v1 kind: Pod metadata: name: nginx spec: containers: - name: nginx image: nginx:1.14.2 ports: - containerPort: 80
Run the kubectl command to create a pod.
kubectl apply -f pod.yml
Check the pod's status by kubectl get pods, you can see a NGINX pod is created successfully by it's status
kubectl get pods
Run the kubectl get pods -o wide command to get more detailed information about the pod-like IP, node, age of node, and status.
To check if nginx is running locally or not, do we have to ssh the minikube go inside the minikube cluster. Then curl the IP address of the pod.
#Get the IP
kubectl get pods -o wide
# SSH into minikube
minikube ssh
# Curl the IP address to access the NGINX
curl http://<IP-Addr>
Task 3: Create NGINX pod on K8s through Kubeadm
Create 2 VM instances for Master and Node.
Install Docker on both Master & Node
sudo apt update -y
sudo apt install docker.io -y
sudo systemctl start docker
sudo systemctl enable docker
sudo systemctl status docker
Install Kebeadm on both master and node.
Again update the system.
sudo apt update -y
Install Kubeadm,Kubectl and Kebelet in both Master and Node.
sudo apt install kubeadm=1.20.0-00 kubectl=1.20.0-00 kubelet=1.20.0-00 -y
Connect Master with Node:
Initialized Kubeadm:
Run the following command only on Master:
sudo su
kubeadm init
Setup the kubeconfig for the current user
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
Finish the Master Setup using the following Command:
kubectl apply -f https://github.com/weaveworks/weave/releases/download/v2.8.1/weave-daemonset-k8s.yaml
Now create a token to join the Master & Node connection
kubeadm token create --print-join-command
We will get nodes for master
After that open port 6443 in master
Then on the Worker Node reset the checks so it can't assign as Master.
sudo su
kubeadm reset pre-flight checks
Paste the Join command on the worker node and append --v=5 at the end
Verify by running the command in Master:
kubectl gets nodes
Create the Nginx Pod
By default, the kubectl run command creates a deployment and a replica set along with the pod. If you only want to create a pod without creating a deployment or replica set, you can use the --restart=Never flag.
But if you pass --restart=Always, if your pod is deleted or having an issue, then a new pod will be replaced immediately.
kubectl run nginx --image=nginx --restart=Never
Now we can see the docker container in the worker node
docker ps
To check if the pods are running or not
kubectl get pods
Get the details of the pod
kubectl get pods -o wide
To delete a pod in
# kubectl delete pod <pod-name>
kubectl delete pod nginx
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