Prerequisite:

First You have to install some Prerequisites for this deployment. For kubeadm installation

https://github.com/farzshamim/Installation-scripts/blob/main/kubernetes_installation_kubeadm.sh

or you can check my blog as well for installation kubeadm with docker and containerd.

https://hashnode.com/draft/64a5bb878bd112000f2654f6#:~:text=kubernetes-,architecture,-and%20Multi%2DNode

Here, i have created two ec2 instance of t2-medium for a smooth operation but you can choose t2-micro for worker node.

Open the ports in security inbound rule 6443, 31001 and whatever is required as per your preference.

Step 1: Clone the code

https://github.com/farzshamim/reddit-clone-k8s-ingress.git

or you can use the image farzshamim/reddit-clone:latest

Step 2: Containerize the Application using Docker

Build the docker image and push it to docker hub.

Dockerfile:

FROM node:19-alpine3.15

WORKDIR /reddit-clone

COPY . /reddit-clone

RUN npm install

EXPOSE 3000

CMD ["npm","run","dev"]

Step 3: Write a Kubernetes Manifest File.

You can refer to the website https://kubernetes.io/ for the format which are available there.

Write mongo-config.yaml file

For database i have choosen mongodb. In data:

key:value=mongo-url: mongo-service

 apiVersion: v1
 kind: ConfigMap
 metadata:
   name: mongo-config
 data:
   mongo-url: mongo-service

2. Write a mongo-secret.yaml file:

In this file, the key:value pairs are specified by encoding in the CLI by using the code : generate yours one by the following

echo -n <username> | base64

echo -n <password> | base64

 apiVersion: v1
 kind: Secret
 metadata:
   name: mongo-secret
 data:
   mongo-user: bW9uZ28tdXNlcg==
   mongo-password: bW9uZ28tcGFzc3dvcmQ=

3. Write a database.yaml file: i.e mongo.yaml

The deployment and service both are in one file. Make sure the labels and selector should be the same. Specify the replicas, container image, and environment of the database you are using in this case: MongoDB and add the secret key reference to the deployment file environment.

The service selector and the deployment label name should be the same and the target port of the service should be same as the deployment container port i.e 27017.

 apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: mongo-deployment
   labels:
     app: mongo
 spec:
   replicas: 1
   selector:
     matchLabels:
       app: mongo
   template:
     metadata:
       labels:
         app: mongo
     spec:
       containers:
       - name: mongodb
         image: mongo:6.0
         ports:
         - containerPort: 27017
         env:
         - name: MONGO_INITDB_ROOT_USERNAME
           valueFrom:
             secretKeyRef:
               name: mongo-secret
               key: mongo-user
         - name: MONGO_INITDB_ROOT_PASSWORD
           valueFrom:
             secretKeyRef:
               name: mongo-secret
               key: mongo-password

 ---
 apiVersion: v1
 kind: Service
 metadata:
   name: mongo-service
 spec:
   selector:
     app: mongo
   ports:
     - protocol: TCP
       port: 27017
       targetPort: 27017

4.Write an web-app.yaml file: i.e reddit-clone.yaml

Here, everything will be the same as above mongo.yaml file. The addition will be:

configMapKeyRef: name: mongo-config key: mongo-url which has been taken from the mongo-config .yaml.
Type: NodePort

with port 3000 redirecting to the external port 31001 to communicate with the browser.

  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: reddit-clone-deployment
    labels:
      app: reddit-clone
  spec:
    replicas: 3
    selector:
      matchLabels:
        app: reddit-clone
    template:
      metadata:
        labels:
          app: reddit-clone
      spec:
        containers:
        - name: reddit-clone
          image: farzshamim/reddit-clone:latest
          ports:
          - containerPort: 3000
          env:
          - name: USER_NAME
            valueFrom:
              secretKeyRef:
                name: mongo-secret
                key: mongo-user
          - name: USER_PWD
            valueFrom:
              secretKeyRef:
                name: mongo-secret
                key: mongo-password
          - name: DB_URL
            valueFrom:
              configMapKeyRef:
                name: mongo-config
                key: mongo-url

  ---
  apiVersion: v1
  # Indicates this as a service
  kind: Service
  metadata:
    # Service name
    name: reddit-clone-service
  spec:
    selector:
      # Selector for Pods
      app: reddit-clone
    ports:
    - port: 3000
      targetPort: 3000
      nodePort: 31001
      protocol: TCP
    type: NodePort

To deploy the app you need to run following the command: First, run the secret and config yaml file by the blow kubectl apply -f command and then the app and database yaml file. kubectl apply -f reddit-clone.yaml Just Like this create a mongo.yaml using kubectl apply -f mongo.yaml

If You want to check your deployment & Service use the command kubectl get deployment & kubectl get services

The app is running in your worker node http://43.204.96.206:31001/

Step 4: Configuring Ingress

Pods and services in Kubernetes have their own IP; however, it is normally not the interface you'd provide to the external internet. Though there is a service with node IP configured, the port in the node IP can't be duplicated among the services. It is cumbersome to decide which port to manage with which service. Furthermore, the node comes and goes, it wouldn't be clever to provide a static node IP to an external service. Ingress defines a set of rules that allows the inbound connection to access Kubernetes cluster services. It brings the traffic into the cluster at L7 and allocates and forwards a port on each VM to the service port. This is shown in the following figure. We define a set of rules and post them as source type ingress to the API server. When the traffic comes in, the ingress controller will then fulfill and route the ingress by the ingress rules. As shown in the following figure, ingress is used to route external traffic to the Kubernetes endpoints by different URLs:

Write an ingress.yaml file

Now you can able to create ingress for your service. kubectl apply -f ingress.yaml use this command to apply ingress settings.
- Verify that the ingress resource is running correctly by using kubectl get ingress ingress-reddit-app command.

Install minikube to enable ingress:

Minikube doesn't enable ingress by default; we have to enable it first using minikube addons enable ingress command.

If you want to check the current setting for addons in minikube use minikube addons list command.

Now you can able to create ingress for your service. kubectl apply -f ingress.yaml use this command to apply ingress settings.

Verify that the ingress resource is running correctly by using kubectl get ingress ingress-reddit-app command.

Expose the app

First We need to expose our deployment so use kubectl expose deployment reddit-clone-deployment --type=NodePort command.
You can test your deployment using curl -L http://192.168.49.2:31000. 192.168.49.2 is a minikube ip & Port 31000 is defined in Service.yml
Then We have to expose our app service kubectl port-forward svc/reddit-clone-service 3000:3000 --address 0.0.0.0 &

Test Ingress

Now It's time to test your ingress so use the curl -L domain/test command in the terminal.

ou can also see the deployed application on Ec2_ip:3000

Note:- Make sure you open the 3000 port in a security group of your Ec2 Instance.

Get Connected:

If you have any suggestion about this post feel free to let me know and be updated on my blog in the following ways:

LinkedIn Twitter Github

#TrainWithShubham #DevOps #chatgpt #AI #devops #devopsengineer #devops2023 #devopscommunity #devopslife #devopsnotes #DevOpsGuys #DevOpsHandbook #devopsinuk #shellscript #linux #kubernetes #kubeadm

Deployed a Reddit Clone app with Mongodb on Kubeadm using 2 nodes cluster with Ingress enabled

Table of contents