Ingress In Kubernetes

What is ingress?

Ingress is set of routing rules that you define inside .yml file. which route should point to service.

There are two types of routing

1. Host Based :

Host based routing such as -> api.example.com, example.com, cms.example.com

2. Path Based

Path based routing such as -> example.com, example.com/products, example.com/payments

So in this blog we will implement path based routing.

If you want to check how to deploy app on kubernetes then first visit below.

How to deploy app using docker on kubernetes

Step 1.

Start minikube

minikube start

Install or add ingress controller

minikube addons enable ingress

Step 2.

minikube addons list | grep ingress

If you have successfully enable ingress then you will see ingress in list

Step 3.

Create two deployments for two different microservices one is nodejs another one is flask

Deployment for Node API

kubectl create deploy node-api-deploy --image=shanikr/nodeapi

Deployment for Flask API

kubectl create deploy flask-api-deploy --image=shanikr/flaskapi:v1

Check list of deployments

kubectl get deploy

Step 4.

Create Services for these deployments

Service for Node API

kubectl expose deployment node-api-deploy --name=node-api-svc --type=NodePort --port=80 --target-port=3000

Service for Flask API

kubectl expose deployment flask-api-deploy --name=flask-api-svc --type=NodePort --port=80 --target-port=5000

Check list of services

kubectl get svc

Go to dashboard check list of pods, deployments, services till now.

minikube dashboard --url

http://127.0.0.1:41787/api/v1/namespaces/kubernetes-dashboard/services/http:kubernetes-dashboard:/proxy/

Step 5.

Create ingress file that defines routes and associated services.

ingress-file.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: flask-node-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
    - host: myapp.com
      http:
        paths:
          - path: /nodeapi
            pathType: Prefix
            backend:
              service:
                name: node-api-svc
                port:
                  number: 80
          - path: /flaskapi
            pathType: Prefix
            backend:
              service:
                name: flask-api-svc
                port:
                  number: 80

Create ingress from this file

kubectl apply -f ingress-file.yaml

Check list of ingress

kubectl get ing

After few second you will see the address has been added

Now open hosts file

sudo vi /etc/hosts

#add this one
192.168.49.2   myapp.com

Save the file and close it

That’s it, it has been done.

Now open terminal make a curl request

curl myapp.com/nodeapi   # this will fetch data from nodeapi service app.

curl myapp.com/flaskapi  # this will fetch data from flask api service app.

That’s great you have done!