Azure Kubernetes Service hasn't created LoadBalancer

Question

I want to publish my website. I have created Azure Kubernetes Service on portal.azure.com but I don't have LoadBalancer:

Should I create a "Service" with type "LoadBalancer"? But I don't know what I should enter in "Port number" and "Target port". Could you tell me? Or maybe I should create "Ingress (preview)", not the "Service"?

On dev.azure.com during creating pipeline - Deploy to Azure Kubernetes Service I have choosen "8080" as a Service Port so maybe I should enter "8080" as a "Port Number" and "Target Port"?

Answer 1

To expose your website running on Azure Kubernetes Service, both ways are correct as I mentioned in the comment section, you can create a Service with type Load Balancer. In the Service manifest, you can specify the port number and target port for your website. If you have chosen "8080" as a Service Port during pipeline creation, then you should enter "8080" as the Port Number and Target Port. Here is an example manifest:

apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type: LoadBalancer
  ports:
  - port: 80
    targetPort: 8080
  selector:
    app: my-app

After you deploy the manifest, you can confirm that the Service is created, and the Load Balancer is configured using the following command:

kubectl get service my-service

When you view the service details, the public IP address created for this service on the load balancer is shown in the EXTERNAL-IP column. It might take a few minutes for the IP address to change from <pending> to an actual public IP address.

Let me take a flask app example that says This is a Hello World application using the below code.

from flask import Flask

app = Flask(__name__)

@app.route("/")
def hello_world():
    return "<p>This is a Hello World application</p>"

if __name__ == "__main__":
    app.run(host='0.0.0.0', debug=True)

Then containerize the app using docker and then build it using docker build -t bravinwasike/flask-kubernetes .

Output:

after that push the Docker image into my Azure container repository using the following commands:

az login
az acr login --name <youracrname>
docker tag <the_name_you_want_to_show_in_ACR> <youracrname>.azurecr.io/<the_image_name_which_you_built>

docker push <youracrname>.azurecr.io/<the_name_you_want_to_show_in_ACR> 

then I deployed the containerized application to the created AKS cluster

Followed by creating a deployment and service (Load Balancer) yaml file that refers to the image that I just pushed in my acr

Deployment and service yaml file combined

apiVersion: apps/v1
kind: Deployment
metadata:
  name: flask-app-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: test-app
  template:
    metadata:
      labels:
        app: test-app
    spec:
      containers:
      - name: test-app
        image: bravinwasike/flask-kubernetes:latest
        resources:
          limits:
            memory: "128Mi"
            cpu: "500m"
        ports:
        - containerPort: 5000
---

apiVersion: v1
kind: Service
metadata:
  name: flask-app-service
spec:
  selector:
    app: flask-app-deployment
  ports:
  - port: 6000
    targetPort: 5000
  type: LoadBalancer

then apply the yaml

 kubectl apply -f <whatever_you_have_named_your_file>.yaml

Done.. Now when I do kubectl get pods my pods are up

and my flask app is up and reachable via the load balancer.

Alternatively, you can use Ingress to expose your website as well. To use Ingress, you need to deploy an Ingress controller in your cluster. Here is an example Ingress manifest:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: your-website-name
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - host: my-website.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: my-website
            port:
              name: http

In this example, the Ingress controller listens on port 80 for requests to the host my-website.com. Requests to the root path / are forwarded to the my-website service on port 80. The nginx.ingress.kubernetes.io/rewrite-target annotation rewrites the URL path to remove the / prefix. You can deploy this manifest using kubectl apply -f <filename>.

References:

• Use a public standard load balancer in Azure Kubernetes Service (AKS)
• Quickstart: Create a basic public load balancer using the Azure portal