In this blog, we will learn about Ingress and how to create ingress rules, So Stay Tuned!
- Minikube Cluster
- kubectl Installed
WHAT IS INGRESS?
Ingress is an API object that allows the external traffic to the Kubernetes cluster based on the routing mechanism. It provides routing rules to manage external users’ access in a Kubernetes cluster via HTTP/HTTPS.
WHY DO WE USE INGRESS?
An ingress is used when you have multiple services on your cluster and want the user request to be routed to the service based on their path.
For Example- If I have to go to geeksforgeeks.com, so the geeksforgeeks domain will point to my cluster and my cluster should know where exactly this request is pointed and that job is done by ingress.
HOW DOES IT WORKS?
In the above diagram,
- The user visits the URL into the browser that basically gets redirected to the ingress service.
- Then service, forwards the request to the controller which then checks the rules, and based on these rules it takes a decision as to where the request has to be sent.
- If it is geeksforgeeks.com, then we will go to this particular service and if it is tutorialspoint.com, then we will go to this service.
- These services act as a load balancer to the pods and hence your request is being sent to the pod through the service.
Moreover for a better understanding, let’s move to the demo
1. If you don’t have minikube and kubectl installed on your system
Therefore, Refer- minikube & kubectl
2. Start your minikube cluster
3. Enable nginx ingress controller
minikube addons enable ingress
4. Check the namespaces
kubectl get namespaces
5. To verify that it is running
kubectl get pods -n ingress-nginx
Now, let’s deploy a Hello World Application
1. Create a manifest file for deployment
apiVersion: apps/v1 kind: Deployment metadata: name: ingress-demo spec: selector: matchLabels: app: myapp replicas: 1 template: metadata: labels: app: myapp spec: containers: - name: ingress-cont image: gcr.io/google-samples/hello-app:1.0
Here, I created a deployment with the name with 1 replica
2. Apply this file
kubectl apply -f [file-name] kubectl apply -f ingress-deploy.yaml
3. Check the status of deployments, pods, and replicas
kubectl get deployments kubectl get pods kubectl get replicaset
4. Now, expose this deployment
kubectl expose deployment ingress-demo --type=NodePort --port=8080
5. Verify the service
kubectl get service
Access the application via the node-ip and the node port
6. To check the node ip
kubectl get nodes -o wide
7. Now, let’s create a manifest file for Ingress
apiVersion: networking.k8s.io/v1 kind: Ingress metadata: name: ingress-app annotations: nginx.ingress.kubernetes.io/rewrite-target: / spec: rules: - host: hello-worldapp.com http: paths: - path: / pathType: Prefix backend: service: name: ingress-demo port: number: 8080
This manifest file is similiar to all other manifest files in kubernetes. Here, kind is Ingress and inside metadata filed, it consists of details about ingress like name, annotations. Inside spec section, we write rules and for rules we will be mentioning the host so that we can access the application with the domain name instead of ip address.
8. Apply this manifest file
kubectl apply -f [file-name]
9. Let’s do the verification
kubectl get ingress
The address filed shoel take couple of minutes
Go to your browser and type hello-worldapp.com
Instead of accessing your applications through ip address and port, create ingress rules and access your applications though domain.